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The endurance athlete’s guide to fueling and weight loss part 5: Hunger etc..

Please read the previous posts if you haven’t seen them before…

We are moving closer to the post where I hope to give useful advice on the different tactics you might use to improve fueling or lose some weight. Or perhaps both.

This was going to be a short post as I was having trouble coming up with a good way to talk about hunger, but I came across some new (to me) information that I hope will be informative.

Hunger

Hunger lies at the intersection of energy balance, brain function, psychology, and group dynamics. Oh, and evolutionary biology. That makes it complex and hard to understand, and therefore not very amenable to easy explanations or simplification. It’s much more complex than – for example – how blood glucose is controlled. I’m therefore going to have to simplify quite a lot, and there will be a number of areas where it’s just not clear (to me) what is going on. That said, let’s get started.

The evolutionary purpose of hunger is to drive us to eat in ways that maintain our energy stores – and in particular, our fat stores – at a certain level. Or perhaps within a certain range. What factors could set the low and high limits of that range? (note 1).

Let’s start at the lower end – what drives the lower end of the fat storage range?

  • If we have too little stored energy, we won’t be able to survive when food becomes scarce.
  • If we are female, we need extra stored energy to be able to build and feed a child.
  • And at the upper range?

  • If we have too much stored energy, we may not be able to move around effectively, which could compromise our survival.
  • There may also be impact based upon climate, but I’m going to ignore that for this discussion.

    Another way to describe the range is “enough fat, but not too much fat”. Where “enough” and “too much” have definitions that are a bit squishy. But you get the idea…

    The regulation of hunger – and therefore the regulation of energy intake – is driven by two hormones, leptin and ghrelin. To oversimplify things:

    Leptin is produced by fat cells, and serves to reduce hunger. Generally speaking, the larger the fat storage, the higher the leptin levels will be. You can think of leptin levels like the gas gauge on a car; if your fat tank is empty, leptin reads low, if you fat tank is full, leptin reads high.

    Ghrelin is produced by the stomach, and serves to enhance hunger. It’s a shorter term signal.

    Based on a simple understanding of how the hormones work, we would expect that Ghrelin levels would be proportional to how long it was since we ate; the longer we went without food, the more hungry we would be.

    Here’s a graph of Ghrelin values over a typical day:

    (note 2)

    The solid line is the average while the dotted lines show the upper and lower range.

    That’s not what I expected. Ghrelin levels are lowest right when we get up, which is when we have gone the longest without eating and would therefore expect them to be highest. It turns out that ghrelin levels have a few somewhat interesting features:

  • They are adaptive based upon when we usually eat and our circadian rhythms.
  • They increase when we start to eat. This is familiar to most of us; not being really hungry but finding out that as we smell dinner or start eating, we are suddenly hungry.
  • There’s another strange feature of ghrelin related to fasting. Here’s a study (note 3) that looked at ghrelin levels over an 84 hour fast:

    image

    That’s just weird. The mean ghrelin levels decrease from day do day, which means you are actually quite a bit less hungry on day three of fast than you are in day one. While weird, this is pretty well established by research.

    Also note that there seems to be a greater reduction for women, for reasons that are not well understood.

    Why our bodies behave this way is not really known. The best theory I know is one from an evolutionary standpoint; while it is good to be hungry if food is available, it can quickly become counter-productive if food is scarce.

    Moving onto leptin, what do leptin levels look like? (note 4):

    image

    That is what we generally expect – at least there seems to be a decent linear relationship between BMI and leptin levels. It’s a bit messy, probably because BMI does not correlate perfectly to fat mass, and likely because of individual variations as well. The differences between male and female leptin levels are asserted to be caused by a) women having more fat mass at a given BMI and b) women having more of the kind of fat cells that produce more leptin than men, though I don’t think the question is truly settled.

    Disfunction

    Leptin is supposed to inhibit significant weight gain; if you gain excess fat, your leptin levels rise, your hunger drops, and you lose fat mass until your leptin levels drop. And that seems to work for some people, especially those who are young, choose their parents well, and male. But it’s pretty obvious it does not work well in a lot of cases.

    Is there anything known about the disfunction? Well, a bit…

    Leptin and ghrelin levels based on types of food

    I found a very nice experiment (note 5) that looks into leptin and ghrelin response based on different kinds of food. Take a group of people, have them fast overnight, and then give them one of three drinks:

  • 500 calories with 80%/10%/10% from carbs, fat, and protein
  • 500 calories with 10%/80%/10% from carbs, fat, and protein
  • 500 calories with 10%/10%/80% from carbs, fat, and protein
  • In other words, a carb-heavy (glucose-heavy), fat-heavy, and protein-heavy drink (note 6). This is done in what is called a “crossover” study, which means that each subject had all three drinks on different days.

    You sample their blood before they have the drink, and then every 30 minutes afterwards, and measure a bunch of different things. Based on how ghrelin works, I would expect that eating would suppress the ghrelin levels and then over time, they would rebound to their previous levels.

    What happens?

    image


    All three produce a significant suppression of ghrelin production, but carbohydrate produces the biggest reduction. Interestingly, however, after about two hours the carbohydrate ghrelin level goes shooting up and after 3 hours it is higher than the fat or protein curves and soon after becomes higher than the initial ghrelin level.

    Or, to put this another way, five hours after eating 500 calories of mostly glucose we would be *more hungry* than we were at the start.

    The authors write, “Our finding of a rebound of total and especially acyl-ghrelin above baseline after high-carbohydrate meals could provide some physiological basis for claims made by low-carbohydrate diet advocates that ingesting carbohydrates prompts an early hunger rebound”.

    Indeed.

    They did measure subjective appetite which showed no effect, though unfortunately they had technical difficulties with the appetite reporting system and that data was therefore not published.

    I’d also like to note that there are many experiments that measure satiety (the inverse of hunger) and show that carbohydrates lead to more satiety than fats or protein. And they do, if you only measure them for 2-3 hours.

    The experiment also measured blood glucose over time:

    image

    If I eyeball the two charts, it looks like ghrelin production starts to go up steeply about the time blood glucose drops quickly at 140 minutes, and is highest when the blood glucose is the lowest. The pattern here matches what is known as either “reactive hypoglycemia” or “postprandial hypoglycemia” – basically the blood glucose drops below initial levels a few hours after eating.

    It’s important to note that the drinks were dominated by a specific macro and drinks with mixed macros may show unexpected results. Though 500 calories is not really that much and these were consumed in a fasted state, and as we know that is the time when the body is best able to handle a lot of glucose.

    You can find the leptin chart in the paper if you’d like to see it; there were small drops over time but nothing very striking.

    Fructose vs Glucose

    Is there a difference between fructose and glucose? Let’s look at another experiment (note 7).

    In this experiment, we take 12 normal-weight women and feed them three meals containing 55%, 30%, and 15% of carbohydrate/fat/protein and take blood samples every 30-60 minutes.

    Of the 55% of the calories that come from carbs, 30% either comes from a fructose-sweetened or glucose-sweetened beverage.  Take a normal meal pattern and make the carbs either fructose heavy or glucose heavy. And sample their blood periodically:

    image

    Wow. Lunch and dinner show large spikes in ghrelin for both drinks, but the late-night spike of the fructose drink is much higher. Also notice the difference in levels at 8am the next day; the level of ghrelin in those who had glucose is quite low, but it’s pretty high for those who had fructose.

    Fructose gives us bigger positive ghrelin peak than glucose.

    They also measured blood glucose levels:

    image

    Based on what we know about glucose and fructose metabolism, that is what we would expect; because the fructose is processed in the liver, there is much less glucose. We would expect that the liver processes the fructose to triglycerides. Is there data to support that?

    image

    Yep. Vastly higher triglyceride levels show the fructose being converted to fat and released into the bloodstream, and those levels persist through the night.

    They also measured leptin levels:

    image

    Leptin levels rose much less for the high-fructose meal, which means there was less inhibition of appetite.

    Overall, fructose led to a greater increase in ghrelin (higher appetite) and a lesser increase in leptin (less appetite suppression).

    So, carbohydrates in general aren’t great, and fructose is worse.

    The best theory I’ve seen around why fructose behaves so differently is that significant fructose supplies were rare in historical times, and therefore it was advantageous for humans to eat as much as possible when they found them. That sounds reasonable, though like many studies in evolutionary biology they are hard to support.

    Leptin resistance

    The mystery of why leptin isn’t behaving as we would expect – why people still eat a lot even with high leptin levels – has been labeled “leptin resistance”, by analogy with insulin resistance; the idea is that for some reason the brain is not sensitive to the levels of leptin.

    Whether there is actual resistance or whether there are other factors that are overpowering the leptin signal is not clear.

    There are a number of theories round what is actually happening. Among them are:

  • There is a defect in transporting leptin from the bloodstream into brain cells across the blood/brain barrier.
  • The cells within the brain become less sensitive to leptin.
  • Dietary fructose leading to elevated triglycerides reducing leptin transport across the blood/brain barrier.
  • Here’s two papers if you want more information (note 8) (note 9).

    Dopamine

    I’m including this section for completeness. There is some research on how dopamine is affected by sugar ingestion, and while I think there something going on there that partially explains why sugar is addictive – at least for some people – I’m not confident enough in my understanding and the quality of the research to have much to offer.

    I do offer a few papers:

    Hunger Summary

    The main points from the preceding section on hunger:

    • Carbs – and especially fructose – seem to interfere with the hunger control system.

    • Hunger is not directly related to how long it’s been since you ate; it has a daily rhythm and decreases when fasting.

    Energy balance and weight loss

    If you have read official guidelines and advice about weight loss, you can generally boil them down to one bit of advice:

    Eat less and move more

    This is often summed up as the “Calories in / Calories out” (CICO) model; eat less means fewer calories in, move more means more calories out, and the result will be weight loss.

    It is also typical to see appeals toward the Laws of Thermodynamics. The more rabid adherents to the model treat it as if they have discovered one of the deep secrets of the universe.

    If you have read the earlier posts and have learned anything about biochemistry, I’m sincerely hoping that you suspect that the reality might just be a *tiny* bit more complicated than the simple world of “eat less and move more”. Especially since that advice fails for a large number of people, at least for the long term.

    There is truth to the CICO model in one sense, if you are losing weight you are burning more calories than you are taking in. And vice versa. But that’s the result, not the driver; the driver is the biochemistry at work.

    The key to understand how things really work – and why CICO isn’t very useful in many cases – is related to how the body responds to a reduction in food intake. The body essentially has three options to balance things out:

    1. It can burn stored fat.
    2. It can tear down muscles (ie “lean mass”) and burn that.
    3. It can reduce its energy use.

      We are hoping that it would do #1 – after all, the whole point of the fat storage system is to provide an energy reserve when food is scarce. But remembering the earlier posts, there are a couple of things that can get in the way of that. First off, we need to be good at burning fat in general. And second, we need to be in a hormonal state where fat burning is possible.

      If either of those aren’t true – or are true only to a limited extent – then we are stuck with tearing down muscle and reducing energy use. And, in fact, that is what we see in a lot of diet studies; people will lose lean mass – sometimes a significant amount – and people report being cold, tired, and hungry all the time.

      And they don’t really lose all that much weight.

      If we can get rid of the conditions that are blocking fat metabolism – and, since we are athletes, up the amount of fat we burn when exercising – then the body should naturally start burning more stored fat, and we should lose weight. Or, to put it another way, we are going to focus on the fat burning side of the house.

      This post is already quite long so I’ve tried to limit the detail in this section; if you want more I highly recommend Peter Attia’s post on fat flux.

      Summary

      There is a lot more that I could write about WRT hunger and energy balance, but I think this is enough for now.

      Our strategy is going to make dietary modifications to reduce hunger and improve our ability to use fat to generate energy while exercising, with a goal to lose weight/improve our ability to perform in long events.

      Which takes us to the tactics portion of the series. What do I think you should actually *do* to implement these strategies, so that you can – with any luck – see the benefits that I’m talking about.

      That will be post #6. When I get that done, I’m planning on doing at least one post to cover any questions.

      Notes:

      1. I’ve tried to base this section on what I’ve learned about evolutionary pressure, fat stores, and hunger.
      2. From Jason Fung’s excellent discussion on hunger and fasting here.
      3. Fasting unmasks a strong inverse association between ghrelin and cortisol in serum: studies in obese and normal-weight subjects
      4. Mechanisms behind gender differences in circulating leptin levels. This result is widely replicated in other studies.
      5. Acyl and Total Ghrelin Are Suppressed Strongly by Ingested Proteins, Weakly by Lipids, and Biphasically by Carbohydrates
      6. The beverages were mostly composed of a glucose beverage, whey protein/nonfat milk, and heavy whipping cream for the carb/protein/fat drinks.
      7. Dietary Fructose Reduces Circulating Insulin and Leptin, Attenuates Postprandial Suppression of Ghrelin, and Increases Triglycerides in Women
      8. Leptin resistance: a prediposing factor for diet-induced obesity
      9. Mechanisms of Leptin Action and Leptin Resistance
      10. MarksDailyApple, by Mark Sisson’s. Mark is an advocate for a way of eating named “Primal”.

      The endurance athlete’s guide to fueling and weight loss part 4: Better fat burning in actual athletes

      Please read the introduction and earlier posts if you haven’t…

      In the last post, I finished by asking what factor or factor might cause the difference between these two athletes:

      image_thumb2

      image_thumb5

      The differences might be genetic, differences in diet, or differences in training. Or maybe something else. What do you think is at play?

      We don’t know all the factors, but it turns out that this athlete does not have a sweet tooth, so he eats closer to the recommended cyclist diet; lots of carbs, but not a ton of sugar. At least in his base diet; I don’t know what he eats before/during/after training. And he’s better at burning fat.

      Hmm. It’s almost as if there might be a dietary effect here, that the availability of carbohydrate in the diet and on the bike might have an effect on fat burning ability. How could we test that?

      Well, let’s put two cyclists – how about these two cyclists? – in a situation where there is much less carbohydrate available, let them train for 10 weeks, remeasure their VO2Max, and see what changes. Since we want to maximize the effect, we’ll put them on a very low carb “keto” diet, which is something like 30 grams of carbs per day.

      What happens?

      Well, athlete #1 is not happy on the keto diet, and that’s really no surprise; he’s not good at producing energy from fat *at all*. If you take away his carbs he will feel horrible on the bike. He ends up making the following adjustments from has previous diet:

    1. He minimizes all sources of sugar
    2. He limits bread, rice, pasta, and potatoes to once or twice a week.
    3. He reduces the food he eats on the bike to an occasional banana plus water
    4. Not really a low-carb diet, but certainly a *lower than before carb* diet.

      Ten weeks of training go by, he retakes the test, and we generate a new graph (previous results are dotted):

      image

      This athlete is now a significantly better fat burner; rather than hitting only 25% of calories from fat, he’s averaging 40% or so across most of his range. His beta oxidation system is better.

      Athlete 2 started with the same very-low-carb diet, and he didn’t stick to it strictly either, but he did mostly get rid of grains and fruit from his diet, and he ended up lower-carb than athlete 1.

      10 weeks go by, and we get this:

      image 

      Yowsa! He nearly doubled the amount of energy he got from fat in parts of his range, and averages over 70% for most of the range. There is also a significant shift to the right, and he produces a higher maximum relative power. That’s great, the low carb diet made him much more powerful!

      Not so fast. Remember that this is *relative power*, and we know that he lost some weight as part of his 10 weeks training, so most of the improvement is likely from the reduction in weight. Though the training may also have helped.

      What did we see across these two athletes?

      First – and most importantly – we saw that a dietary switch made significant changes in the fat metabolism ability for both athletes. This really isn’t very surprising knowing what we know about the underlying biochemistry, but it does show very clearly that beta oxidation capability can be trained.

      Second, we saw a correlation between the amount of carbohydrate in the diet and the overall ability to metabolize fat.

      I do want to add a few caveats. The first is that two cyclists is a very low sample size, and the second is that we can’t tell the difference between changes due to base diet and changes due to food before/during/after. And there may be a genetic component at play here.

      Returning to my RAMROD example from the last post, let’s add in two more lines, corresponding to getting 50% of calories from carbs and supplementing 200 cal/hour (yellow) and getting 25% from carbs and supplementing 50 cal/hour (blue). These lines are closer to the “after” graphs of the two cyclists.

      image

      If I can get up to 50% fat utilization and supplement at 200 calories per hour, I should be able to go 12 hours without running out of glycogen. And if I can get up to 75% from fat, I can supplement at only 50 calories per hour and still easily make it to 12 hours.  I can maybe get to 12 hours without eating anything at all…

      It may be better than that. Remembering back to the first post where we talked about triglycerides, and how those are composed of a glycerol backbone with three fatty acids attached to it. If we are burning lots of fatty acids in beta oxidation, that means the fat cells are breaking apart triglycerides, and that means we have a lot of extra glycerol around.

      Since the body doesn’t want to waste energy, it will try to use the glycerol for something useful, and it can turn it into glucose through gluconeogenesis. That means if we are burning a lot of fat, we will get some glucose out of it to support the glycolysis side. And no, I don’t know how much “some” turns out to be, this is hard to study.

      Some more data

      Is there more data out there that would be interesting?

      Jeff Volek and Stephen Phinney have done a number of studies looking at low-carb/keto diets and athletes (note 1), and here’s one that I think is relevant to this topic:

      Metabolic characteristics of keto-adapted ultra-endurance runners

      One of the problems with dietary studies is that the studies are expensive and time is limited, so it’s very hard to do studies where you change an athlete’s diet and check to see how it affects her for the next 12 months. That is why many of the studies around keto diets and athletes are extremely short; less than 3 weeks. Knowing what we know about how long it takes to achieve training gains in general, it’s pretty clear that 3 weeks is on the short side to see adaptations, so I don’t think most of those studies are very good.

      In this study, Volek and Phinney instead looked at two groups of elite ultra-endurance runners, 10 who followed a high-carb diet, and 10 who followed a low-carb diet. Since each group was on their habitual diet, it’s a pretty good bet they were adapted to it pretty well. I will note at the outset that this is an observational study and therefore there is the possibility that the runners who chose low-carb are genetically better at burning fat than the high-carb ones.

      From the hypothesis about trainability, what difference would we expect to see in fat burning rates between the two groups? Here’s the first graph:

      image

      The graph shows the peak fat oxidation during a 3-hour run for all of the athletes. Every low carb athlete is significantly better at burning fat than even the best fat-burning high carb athletes. If we look at the averages (circles to right), the average in the low carb group was 2.3 times higher than the high-carb group.

      I’d also like to note that the average for the low carb group was 1.54 grams/minute. That would be 92.4 grams/hour, or a whopping 92.4 * 9 = 832 calories / hour from fat burning alone.

      Where did that peak fat oxidation occur? Here’s another graph:

      image

      Here we are looking at the relative intensity of that fat peak for each runner; the HC group peak was at 54.9% of VO2max, and the LC group peak was at 70.3%. Not only are the low carb athletes burning more fat, they are hitting their peak at a higher intensity.

      It is pretty clear that the low carb athletes are burning vastly more fat during a long run than the high carb athletes. And this study was with elite athletes doing ultra-distance events, which means even the high-carb athletes are likely to be decent fat burners.

      There are some other interesting graphs in the paper that I recommend looking at (note 2), and we may come back to it later.

      Summary

      We found out that there seems to be a strong training effect and we can expect to improve the rate at which we burn fat through training. We also learned that if we can do that, it can make fueling more straightforward on long rides; we may need to still supplement, but likely not as much.

      In the next post, we’re going to take a little excursion into talking about weight loss and hunger.

      Part 5: Hunger etc.

      Notes:

      1. Phinney and Volek have written a couple of books that cover this same subject area: “The Art and Science of Low Carbohydrate Living” and “The Art and Science of Low Carbohydrate Performance”.
      2. Section 3.2 talks about submaximal substrate utilization, and features two charts that show the average oxidation rates (in grams/minute) for both fats and carbohydrates. The low carb group was very steady across the whole 180 minutes of the run; both fat and carbohydrate utilization is nearly a flat line. The high carb group saw a drop in carbohydrate and increase in fat over time; they also saw a slight reduction from 13.2 cal/minute at the start of the run to 12.0 cal/minute at the end.


      The endurance athlete’s guide to fueling and weight loss part 2: Energy Systems

      Please read the introduction and earlier posts before reading this one.

      In our last episode, we learned about how fat and carbohydrate get into our systems and the fundamental asymmetry between those two systems.

      In this episode, we will look at how fat and glucose are used for energy. My focus is going to be on muscles since these posts are for athletes; there are similar concepts that apply to other tissues but they are beyond the scope of this discussion (see note 1)

      I’m going to have to dive into some biochemistry to create a framework for further discussion; I have tried to simplify it as much as possible, and the post is relatively short.

      This is a summary of the overall processes at work for aerobic energy production; there are others that are at work for non-aerobic production.

      Each of the boxes is a complex series of chemical steps (note 2)

      image

      We’ll start at the bottom and work our way up.

      Citric acid cycle

      Our goal is to take fat and carbohydrates and create ATP, which is what powers our muscles. At the center of the diagram is a compound named acetyl coenzyme A, abbreviated as “Acetyl CoA”. You can think of Acetyl CoA as the common energy compound produced from either glucose or fatty acids. That’s not absolutely correct, but it’s correct enough.

      The Acetyl CoA feeds into the citric acid cycle (sometimes known as “Kreb’s Cycle” after one of the discoverers). If you want to see the details, here’s a link:

      Image result for don't press this button image

      You pressed it, didn’t you?

      Biochemistry is just ridiculously complex.

      All of this takes place inside of each of most of our cells. You probably studied cells when you were in biology class, and the diagrams looked something like this:

      Image result for simple cell nucleus mitochondria

      Specifically, the citric acid cycle happens within the mitochondria, which you can see are those oval-shaped structures within the cell. I generally think of cells as being these little spheres or flat discs, and some are, but muscle cells are a bit different:

      Image result for muscle cell nucleus mitochondria

      Not at all like a globule or a flat disc; I especially like the nucleus stuck on the side as an afterthought.

      Muscle cells need a lot of energy so they have tons of Mitochondria. Thousands of them.

      And how are we going to get all the Acetyl CoA that we need to drive those muscles?

      Glycolysis and Beta Oxidation

      Glycolysis is the the process that converts Glucose to Acetyl CoA. Beta oxidation is the process that convert fatty acids to Acetyl CoA. Both of these processes happen in the mitochondria.

      There is a very important point to be made about glycolysis and beta oxidation. Even though they both occur in the mitochondria and even though they both feed into the citric acid cycle, they use different chemical pathways and therefore use different machinery.

      The citric acid cycle, glycolysis, and beta oxidation can all be trained. Not only can the body build more mitochondria, it can improve the rate at which each bit of machinery in the mitochondria works. That is one of the adaptations that makes us better at aerobic exercise.

      But the body only makes improvement to the parts of the machinery that are being stressed, so if it’s glycolysis that is being stressed, improvements will be made in the glucose metabolism, and similarly if beta oxidation is stressed, improvements will show up in fat metabolism.

      This point is going to be fundamental to our next discussion, so I’ll state it again in a different way – you can be an athlete with a very powerful glycolysis pathway and a crappy beta oxidation pathway. And vice versa.

      Another interesting outcome is that to achieve higher performance, you need to improve either glycolysis or beta oxidation *and* the citric acid cycle. You can do a bunch of work to improve your beta oxidation and you’ll burn more fat and fewer carbs, but you won’t see higher performance if the citric acid cycle is unchanged (note 3).

      Summary

      This was a short post and I’m not sure I really need a summary, but the short one is that both fat burning and glucose burning have separate chemical reactions (glycolysis and beta oxidation) that feed into a shared set of chemical reactions (the citric acid cycle) that ultimately give the energy to drive the muscles.

      That’s all for this post. The next post will take this post and apply it in real-world situations.

      Part 3: Carbohydrate and fat use in actual athletes

      Notes

      1. That would take us into ketone bodies and their usage in different tissues.
      2. Like, ridiculously complex. In glycolysis, to get from glucose to pyruvate – which is fed into the citric acid cycle – takes a series of 10 different chemical transformations. Beta oxidation goes through 5 steps but repeats them for every two carbon atoms on the fatty acid, and it’s more complex for unsaturated fatty acids. The citric acid cycle has 9 steps.
      3. This depends a bit on what you mean by “performance” and it ties into fueling, which will come up very soon in a future post.


      The endurance athlete’s guide to fueling and weight loss introduction

      I’ve always been interested in nutrition for athletes, and as a serious recreational cyclist – whatever that means – I’ve played around with a number of different approaches. And I’ve read a lot of books that explain how to do the “standard athlete diet”, and done my best to follow them.

      But there were a couple of things that had me confused…

      The first was my inability to come up with a nutrition strategy that worked for me on very long and hard rides. Invariably, if I got beyond about 7 hours, I felt sick and weak, and sometimes it happened earlier.

      The second was just an observation at first; there were people I rode with who rode a *lot* more than I did but still carried a significant amount of extra weight – 30 or even 50 pounds. I knew from talking with them that they ate like I did, and they were already riding in excess of 5000 miles a year, so more exercise couldn’t be the answer. It was quite the puzzle, but it took getting into my 50s and finding that my weight was no longer easily controlled by cycling and that I was having energy issues in the afternoon to compel me to investigate a bit further.

      That led to a period of two years where I learned a lot more about physiology and taught myself enough biochemistry to be moderately dangerous. And changed both my diet and fueling strategy significantly.

      And, incidentally, I lost around 15 pounds. I was 178 pounds to start, and at 6’1”, that’s reasonably light, but at 163 pounds, I’m now “cycling light”, and that’s made a big difference on the rides I do.

      This series is my attempt to put down the important things that I’ve learned in a coherent manner so that others can benefit from it, and I can get clear in my head what I think I know.

      I’ll warn you at the outset; I’m going to be talking about biochemistry because that understanding is pretty critical when we get to talking about strategies and tactics. I have tried to make it “Just enough biochemistry”.

      The following is a list of the various posts. I really recommend reading them in order as the later posts build on the earlier posts.

      1. Part 1: Macronutrient intake and storage
      2. Part 2: Energy systems
      3. Part 3: Carbohydrate and fat use in actual athletes…
      4. Part 4: Better fat burning in actual athletes…
      5. Part 5: Hunger etc…

      The endurance athlete’s guide to fueling and weight loss part 1: macronutrient intake and storage

      If you haven’t already, I recommend reading the introduction

      We’re going to start by going into the biochemistry of how the various macronutrients – fat, protein, and carbohydrate – make it into our bloodstream and how they are stored.

      I’ve simplified the biochemistry as much as practical. If you want more details, you can start with the chapters about fat and carbohydrate metabolism in Marks Medical Biochemistry, but I’ll warn you that biochemistry is annoyingly complex.

      Digestion and Storage

      Fat

      When we eat fat, we are eating triglycerides, which look like this:

      Image result for triglyceride

      Triglycerides are simply 3 fatty acids hooked to a glycerol backbone. The fatty acids are just chains of carbons with hydrogens attached to them and then what’s called a hydroxyl group (pink in the image) at one end. Discussion of fats is imprecise; sometimes we talk about “fats”, sometimes “fatty acids”, and sometimes “triglycerides”. You can treat all those as equivalent for this discussion.

      The fatty acids shown here are saturated fatty acids; the differences are mostly immaterial for the purposes of this series, so I’m going to ignore them.

      After digestion, fatty acids end up in the bloodstream, our adipose (fat) tissue pulls them in, and stores the fatty acids away. Very simple and the system works quite well.

      The amount of energy you can store in fat cells is close to unlimited. Even only 10 pounds of fat stores about 35,000 calories, which is a ton of energy; that’s about 1000 miles of riding for the kinds of rides that I do.


      Protein

      The protein in the food we eat is broken apart into individual amino acids, absorbed into the bloodstream, and… Well, at that point it gets a little weird.

      There is no centralized storage for protein in the body. There is a what is called the “amino acid pool” in each of the cells, but generally speaking, if we eat more protein than is immediately usable by the cells, the rest is excess. Most of the excess amino acids can be converted to glucose through a process known as gluconeogenesis, so some of the excess energy becomes blood glucose, but if there is too much, it is just thrown away.

      Now, if you look at it another way, you can view muscles as a centralized storage for protein. There is something known as “protein sparing” where the body generally tries not to tear apart muscles to get energy, but if the need is great, the body will tear down protein, convert it to glucose, and burn it. If you’ve seen the pro cyclist upper body muscles, you can see this effect in action.


      Carbohydrate

      Carbohydrates are much more complex; unlike the fat system, where all fatty acids are treated equally, the different sugars are treated quite differently. I’m going to talk about how the various sugars get into the bloodstream and what form they take before I talk about storage.

      Glucose

      Image result for glucose

      Glucose is one of the common currencies for energy in the body. When you eat glucose, it is absorbed into the bloodstream.

      Starch/Maltodextrin/Dextrose

      These are sometimes known as “glucose polymers”, which is a fancy way of saying “chains of glucose”. The chains are broken apart into glucose in the digestive system before they are absorbed and that generally happens fairly fast.

      You can treat dextrose, maltodextrin, and most starches as if they were glucose from a nutritional perspective. There are a few exceptions; there is “resistant starch”, which doesn’t get digested easily and can be converted to fat in the digestive system by bacteria, and a cool product known as SuperStarch that I’ll talk about in a later post.

      Sucrose/Fructose

      Sucrose is a disaccharide, which means it’s a compound of one molecule of glucose and one of fructose. You can treat the glucose part just like any other glucose molecule.

      The fructose part is more complex. Some fructose may get digested into fat in the digestive system, but the fructose that makes it into the bloodstream cannot be used directly by the cells of the body. Rather than waste that energy, the liver takes the fructose molecules and does a bit of processing on them. If glucose is rare (blood glucose is not high), the resulting compounds will become glucose, and if glucose is common, it will convert those compounds into fatty acids, which is released (if you are lucky) or accumulates (if you are not lucky). More on that later.

      High fructose corn syrup is about 55% fructose and 45% glucose, so it’s pretty close to the same mixture as sucrose and from a dietary perspective, you can treat it the same.

      I should also note that some people have varying degrees of fructose intolerance; it can cause what is politely known as “digestive issues”. If I eat any fructose during exercise I will get immediate stomach issues. I mention this because it took me a long time to figure out.

      Lactose

      Lactose (milk sugar) is another disaccharide, in this case a combination of glucose and galactose. The glucose is like any other glucose, the galactose is like fructose in that it can only be handled by the liver.

      Alcohol

      What we call ‘alcohol’ – ethanol – is lumped together with other carbohydrates even though it is not a sugar. Ethanol can only be metabolized through the liver, and like fructose and galactose, it might end up as glucose or it might end up as fatty acids.

      Blood glucose levels and glucose storage

      Much of the physiology we’ll talk about is driven by blood glucose levels. There are two big things to know:

      Thing 1: There is a narrow range for healthy blood sugar levels

      When blood sugar is not in a narrow range, bad things happen. Normal fasting blood glucose levels are around 80 mg/dL (milligrams per deciliter). If you get below 50 or so, you can end up in a coma, which is bad; that is what happens to type I diabetics if they get too much insulin. If you get above about 215, you need to seek medical attention, and above 300 is an immediate risk. And moderately high levels on an ongoing mean that you have type II diabetes.

      Thing 2: The quantity of glucose in the bloodstream is small

      How much glucose is in the blood? Knowing that an average fasting blood glucose is 80 mg/DL and  that the average adult has about 5 liters of blood in their bloodstream – 50 dL – we can do some very simple math:

      glucose content of blood = 80 mg/dL * 50 dL = 4500 mg = 4 grams

      How much is that? About this much:

      Image result for sugar cube.

      One small sugar cube. There is a *tiny* amount of glucose in the bloodstream.

      The small range of normal blood glucose levels plus the small amount of glucose in the blood means that even a modest amount of glucose coming in from the outside could have a huge effect on blood glucose levels; a mere 4 grams of glucose would double the blood glucose level if there were no mechanism to deal with the extra glucose. The body therefore devotes significant amounts of machinery to try to keep blood glucose constant.

      Blood glucose level is regulated by the pancreas. As the cells of the body pull glucose out of the blood, the level drops, and the pancreas releases the hormone glucagon. The glucagon signals the liver to release some of its stored glucose into the blood stream to bring the blood level back to normal. The liver can store about 100 grams (400 calories) of glucose, which it stores as glycogen. If the liver glycogen stores are chronically low – if you aren’t eating many carbs on an ongoing basis – the liver can make glucose from other compounds – like lactate, the glycerol from triglycerides, and some amino acids from protein – using process known as gluconeogenesis – and it can also switch some tissues to use ketones rather than glucose to reduce the required amount. If you aren’t eating anything – if you are fasting or starving – your body can still make the carbs you need.

      Low blood sugar is the less interesting case, because the body is (generally) quite capable of dealing with it. The more problematic part is high blood glucose…

      If you eat something with carbs, as they are digested you will end up with glucose coming into the bloodstream. The pancreas detects the raised blood sugar, and starts releasing insulin, which is a signal to other tissues to do their best to pull glucose out of the blood. There are 3 main effects from the elevated insulin:

      First, the burning of fat is minimized so that as much glucose can be burned as quickly as possible. The more glucose being pulled out of the blood, the less the blood glucose level will rise.

    5. Second, the liver will start pulling glucose in and storing it as glycogen, as long as it has space. The muscles will also start pulling glucose in if they have space to store it, and the muscles can store around 400 grams (1600) calories. Conversion from glucose to glycogen is quick and there are a lot of liver and muscle cells, so if glycogen stores aren’t full, the glucose will quickly be pulled into those cells, and blood sugar won’t get very elevated. But compared to fat, the storage is quite limited, and it’s very rare that glycogen stores are low; muscle glycogen is only burned through activity, so it’s generally only the liver storage that is in play, so there’s often just not much space to store glycogen. 
    6. The third effect happens if the liver and muscle glycogen stores are full. There is no easy place to store the glucose but it’s still coming in from the digestive system, so the blood glucose level goes higher and the pancreas releases more insulin. There is only one place for this excess glucose to go, and that is fat, so the liver and the fat tissue pulls in glucose and converts it to fat. This is slower than the conversion to glycogen, so the elevated blood sugar and insulin levels persist for a few hours.

      Because that it is highly important to keep blood glucose low and limited storage space, there is a fundamental asymmetry between the fat and carbohydrate storage systems, and that asymmetry drives a lot of the physiological response.

      The big upshot of this – the reason I’ve talked so much about the underlying biochemistry – is that the two big effects of lots of carbs are a) converting excess carbs into fat and b) turning off fat burning while that process is happening. If you’ve ever “carb loaded”, you deliberately put yourself into this situation. It *does* push a little more glucose into your glycogen reserves, but most of the excess carbs just go straight to fat. Will they stay as fat? Well, that question will be covered in a future post…

      Insulin Resistance and type II diabetes

      It seems like an appropriate point to talk about what is different for people who have insulin resistance or type II diabetes.

      The previous explanation is how it works if you are metabolically healthy – if you don’t have insulin resistance / type II diabetes.  Here’s a graph:

      The normal person sees just a small spike of glucose and it quickly returns to normal, the pre-diabetic sees a spike and then a drop afterwards (this is likely not true for all pre-diabetics), and the type II diabetic starts with an elevated glucose level and a meal just spikes it way up.

      Part of what we are seeing is that the liver and muscles become less willing/able to absorb glucose out of the bloodstream, so it takes longer for the blood glucose to return to normal. When we get all the way to type II diabetes, there is something else going on. Earlier I talked about the process to deal with low blood glucose by converting liver glycogen to glucose. This normally only happens when blood glucose is low, but insulin resistance messes up the machinery that controls this, and the liver will release glucose even when glucose is normal or elevated. That is why the blood glucose is chronically high.

      The result is that those who are insulin resistant have chronically elevated levels of glucose and insulin, and since we know that elevated insulin reduces fat burning, they find it very hard to burn fat.

      Insulin resistance is not a binary thing, and it’s possible to be a little insulin resistant and not have it show up in standard tests. It is not confined to people who are overweight; it is possible to be insulin resistant and have a normal body weight.

      Summary

      Protein and fat digestion and storage are pretty simple, but because of the limited storage available for carbs, excess carbs just get stored as fat.

      Now that we’ve gotten that fat and glucose stored, in the next post we’re going to talk about how those are used by the muscles.

      Appendix

      This section contains some related information that isn’t necessary for the discussion but may be of interest…

      Protein and insulin

      I glossed over the relation of insulin to protein earlier in the post, but it comes up often enough I thought it was worth covering here.

      Insulin is a multipurpose storage hormone; not only does it signal the body to store glucose, it also signals it to store protein.

      But how can that work? Let’s perform a little thought experiment:

      We eat a high protein meal and the pancreas secretes insulin. That would cause the amino acids from the protein to be absorbed, but it would also tell the liver, muscle, and fat cells to pull glucose out of the bloodstream, and would therefore cause the blood glucose to plummet.

      Which would be bad.

      This is one of the simplifications that I made to keep things simpler. It turns out that the liver, muscle, and fat cells are not sensitive to the amount of insulin in the blood but rather to the ratio of insulin to glucagon in the bloodstream. Here’s a graph for what happens after a carbohydrate-rich meal:

      Image result for insulin glucagon protein meal

      Notice the inverse relationship between the insulin and glucagon values; this will move the insulin/glucagon ratio much higher so the glucose will be absorbed.

      Here’s what happens with a protein-rich meal:

      Image result for insulin glucagon protein meal

      There is a small insulin spike from the protein, but a large glucagon spike. That keeps the insulin/glucagon ratio low and blood glucose constant.


      Passport2Pain 2018

      This is my third attempt at the “Idiot Level” Passport2Pain course, and my third completion (2013, 2016, and 2018). In 2016 I left my GPS at home and apparently didn’t bother to write anything up, so any comparisons will be to 2013.

      My wife and I went over Friday afternoon to have dinner with and stay at the house of one of our ski instructor friends, who very conveniently lives 15 minutes from the starting line. I slept poorly as is my usual before big rides, but got up, skipped breakfast, and we headed over to the starting point.

      After the usual wait and ride introduction (“In thinking about fundraisers, we had an idea. It wasn’t a *good* idea, but it was an idea…”), we queued up to start. They start with 4-5 riders every 30 seconds or slow to spread the riders out. Contrary to the pre-ride description, they made no effort to actually send out the idiot (80 mile) route riders first; I knew to line up near the front but I would have been upset if I had to wait 40 minutes to start. Considering the difference between the two routes is well over two hours, they need to do better at this.

      We pedaled away from the start at Jensen Point, which is on this weird little spit. I started talking with a guy in a t shirt, jersey, and cutoffs; he had forgotten his clothes. He pulled ahead and took the first turn to exit the park area and immediately pancaked on this left side.

      It had, you see, rained the night before and it was 57 degrees and cloudy. So there was still a bit of moisture on the road, and likely a bit of oily film.

      He was fine and we rode off to start our quest, and I made a mental note not to ride too near to him – or any other riders – while the roads were wet.

      I generally describe P2P as riding all the way around Vashon island and taking every road that goes down to the beach.

      image

      That is hyperbole. There are, in fact, numerous hills that will will not ride down, but we will ride down a large number; overall, there are 25 climbs on the ride, most of which are in the 200-300’ range, plus a bunch of small hills and rollers. If you are doing a ride like RAMROD, there are really only 3 hills (Paradise, Backbone ride, and Cayuse), and that’s how you track your progress. On P2P they do have checkpoints where you get your passport stamped, but there are 18 of them.

      My approach is to just ride; I know what the parts are, and I know that I need to ride slow because the last set of hills is pretty bad.

      So, we head off, do a short climb, and then descend down to the first real climb, which is a weird down and up. And quickly run into our first issues.

      We roads and steep climbs do not mix. Going down you can just take it easy, and even with disc brakes I’m taking it easy on the still wet roads. The problem is when you start having to go up again. I can sit and ride up a 15% hill pretty easily and tough out a 20% hill, but it’s nice to be able to stand. Except if you do that, your rear wheel spins up. Which is bad. So, you just need to sit and suffer.

      The first 5 stops go by pretty fast; slow and careful on the descent, and then doing my best on the climbs to stay smooth and keep calm. This part of the ride is the warmup, though it’s a little nuts that the warmup has 8 main climbs and 2500’ of up over the first 25 miles. We then have 5 miles with a climb or two, and then turn off onto Burma Road.

      Burma is a mostly paved goatpath that rolls up down and around; they laid asphalt with doing as little grading as possible. Burma has one easy climb – say 13% or so – and then two hard climbs. They are aren’t very high, but they are well in excess of 20% (my GPS said 27 but I really don’t think they are quite that bad). The general way to attack Burma is to be able to ride slowly – say 3MPH – while standing, and if traffic permits, do a slight weave back and forth. It’s not categorically different than “The Widowmaker” in Sufferin’ Summits, and it’s quite a bit shorter, though it’s barely one lane wide.

      That is what I did on two previous rides, but Burma is fully shaded and quite wet this year. After spinning the rear up despite being really gentle, I just ride slowly and muscle my way up. Not fun at all and I’m stressing my legs much more than I hoped, but it’s either that or just fall over (I don’t think I could unclip and stop), so I ride up both pitches apprehensively and then get to meet the devil.

      Almost directly after, there’s another hill with a torn up descent at the bottom where you can barely stop and an ascent where you can’t stand, but that’s par for the course. Later this same hill has a solid 20% section, but luckily that pavement is dry and a real road so you can tack/paperboy back and forth and stand if you want to.

      There’s one more loop down to the water, a spin along the main highway, and we hit the lunch stop.

      I’ve been snacking a bit along the way; I have some nuts and I’m eating small amounts of carbs, and that’s working great except for 5 peanut M&Ms that give me a knot in the stomach.. At this point, I’m pretty tired and deciding whether to do the 55 mile or the 80. I eat the fillings of a very forgettable BLT and a bit of bread and then stop at the Thriftway for a Coke Zero but am stuck with a Diet Coke.

      I mean, seriously, what are they thinking?

      I text Kim to let her know where I am (she is doing a ride into the village for coffee) and tell her I’m 50/50 on which variant I will do and I’ll text her when I decide.

      I roll out. There’s a small and ugly climb on the next section, but this one is dry and I’m feeling decent until my right hamstring starts to cramp near the top of the hill. I stop, dig some electrolyte capsules out of my pack, and wash them down. Then it’s off to Evil Twin #1 and #2. They really aren’t that bad and I’m climbing a bit better after food and Diet Coke. The second stop has chips and guac, and I have a few, heavy on the Guac.

      And that’s all the hills on the 50 mile/6500’ route, so I need to make a decision. My toes and left shoulder hurt a little, but my legs are feeling okay, so I stop to text Kim and press on, onto Maury Island, and get ready to grit my teeth. Because as tough as the Burma Road section is, this section is a real bastard. It looks like it won’t be that bad – there are only 5 stops – but it’s a full 30 miles and over 3000’ of up.

      We work our way through 14, and then descend down to 15. This has the added pain that as I near the stop, I ride by our friend’s house and out in front my Outback is parked, with a perfect bike-shaped space in the back, beckoning to me. I manage to avoid the temptation, but man, the hill out is a major bitch, and I’m tacking back and forth for all I am worth. And it’s not like I’m getting passed much, since all the fast people are in front those near me are bound together in a brotherhood and sisterhood of suffering and pain.

      On the plus side, I’ve had no more cramping issues, so there is that.

      Then there’s an ugly descent, and we ride into Dockton. We have three stops left, so three hills, right? How bad could that be?

      I hate Dockton. We are down right at the water, but we climb 300’ up to the top of the island, and then we descend all the way to the water down yet another sketchy, wet, and slightly mossy road. For a measly stamp on our passports. Then we climb out that same damn hill, though the way from the water is worse.

      And then – and this is the wonderfully terrible part of this ride – we do it again. Climb 200’ up into the hills, all the way down to the water, collect our penultimate stamp, and then it’s another 250’ climb back to where we started.

      And the pain of Dockton is over. At this point I’m feeling pretty good; I *know* can finish the last hill, and then there are only a few rollers after that. I ride up a 150’ uncategorized hill – I mean really, it’s only a 7% and it feels very easy – in company with another rider, and I form a plan.

      There is only one hill left and my legs feel like they have a little something left. So, we come to the last hill – 330’ of fun or so – and I start climbing hard, which is somewhere between 230 and 280 watts as the hill steepens and eases (my earlier target was <200 watts if I could). My data shows that I’m 43 seconds faster than my 2013 ascent – a full 9% faster. I get to the top, have a little bit of popcorn, and spin out to finish the ride.

      The way back is about 4 miles with only a few rolling hills, so I push my speed up a bit. And then, finally, I finish, and get to have some well-earned barbecue with my spouse. It’s pretty good in the “Puget Sound Barbecue” category, but the brisket needed another couple hours in the smoker.

      Analysis

      Strava says I pulled 12 PRs on the route, and 9 of those were on hills. That makes me pretty happy, and I felt strong for most of the ride. It’s so much nicer and prettier than Sufferin’ summits.

      Stats:

      80.81 miles
      7:11:46 riding time
      9,949’ of up
      11.2 mi/hr average

      How does that compare to 2013? Well, in 2013 I rode 1.5 miles farther, which was probably due to more back-and-forth across the road, and finished in 7:13:27. My average speed then was 11.4 mil/hr, faster than this year, but my speed on descents was at least 25% slower than before because of the wetness.

      2013’s ride was done on my Trek Madone, a fine bike for making speed but it was pretty harsh on the crappy Vashon roads. This year I was on my Roubaix with disc brakes, a frame tuned to soak up vibration, shocks in the seat and steering head, and 28mm tires at 80 psi. It was gloriously better; the stuff that really would have beat me up last year was still annoying but not too bad.

      image


      Training Wheels Very Very Late Spring Canadian Century

      Because of a conflict, I was unable to ride Flying Wheels this year, but since I have some bigger rides later in the summer – including DORMAR (RAMROD backwards) – I wanted to get in a nice long ride.

      So, I decided to go out and ride a century. But just riding the Flying Wheels route would have been too easy, for a couple of reasons:

      First, I live a little over 5 miles from the starting point, and if I ride there and back that would be an extra 11 miles or so.

      The second reason requires a bit of an explanation… I’ve been leading rides around the Eastside for a number of years now and did my own routes before that. So… I have a particular attitude about routes. Perhaps a Venn diagram would help:

      image

      Rare is the route that I won’t find something to complain about. Some of my complaints are based in fact, but many are based on reasons.

      So, anyway, a little route-tweaking was in order. The big changes I made were:

      1. Starting the route at my house
      2. Ending the route around the south end of Lake Sam to make it a little simpler; otherwise I would ride all the way to the North end just to ride South again.
      3. Getting rid of about 7 miles of farting around in North Bend. I know that they need to find some extra distance someplace and this was an easy way to do it, but I really find that section to be tedious.

      That gave me 99.8 miles, or something like that.

      The ride

      I woke up, skipped breakfast – as I generally do before long rides these days – and got dressed. The weather was in the mid 50s, trending into the low 60s later on. I positively hate that temperature range; it’s just a bit too cold for bare legs for me, but it’s going to be too hot for leg warmers later on. Arm warmers are easy to fit into a jersey pocket; leg warmers are a lot harder. Unsure, I went and stood outside for a few minutes, and decided that if the sun held up, bare legs would be okay.

      Did I mention that the forecast was for partly cloudy? Yeah…

      Before I got dressed I drank down 3 scoops of SuperStarch with a half scoop of Endurox to make it slightly less repulsive. The SuperStarch is based on cornstarch, and a big glass of water with a lot of suspended cornstarch tastes exactly as good as you think it does.

      In my pockets was a ziploc bag of Cheez-its that had seen better days and a single Honey Stinger Chocolate Waffle. I’m experimenting with a bit of carb supplementation recently. I had my arm warmers on and was wearing a stuffable vest.

      I rolled out of the driveway at 8:15 and immediately ran into a problem. Well, two problems. The first was there was a bit of a headwind coming from the North, which would slow me down and make things a bit cooler. The second was that my legs hurt and felt flat.

      After an 8 mile warmup, I came to the base of Inglewood hill, the first on the docket for the day. If you climb Inglewood during Flying Wheels (I have been known to ride up the harder Sahalie drive climb instead), you will know that it is somewhere between a hot mess and complete carnage. I avoid it on my rides because I just don’t like it very much, so this was a rare solo ascent for me.

      On climbs, it’s great if you can find a rabbit. A rabbit is a rider in front of you that you can try to catch. Ideally, the rabbit is just a bit slower than you so that you can make up some time on them during the climb. Early on a weekday morning, there were no rabbits to be found, but halfway up I looked to the side and found that I had a deer who was pacing me just off the side of the road. She’d stop for a moment, I’d get closer, she’d run forward a bit and stop, and the cycle would repeat itself a few times. We eventually came to a road, where she hesitated and I tried to figure out how I could bail because 25’ is way to close, and then she took off into some woods. The rest of the hill was soon dispatched. Not one of my better climbs, but I was at the top.

      The next hill is 236th, climbing from 202 up into the Redmond Ridge/Trilogy developments at the top of Novelty hill. It will surprise you not at all to find out that I think this routing is a mistake. I don’t think it’s necessarily too hard for the century riders, but I do think that it’s too hard for the 47 and 67 mile riders. In the old days, we went east and climbed up Ames Lake; though that does require a left turn that isn’t the safest, I still think it’s a better choice. The century riders could climb up Union Hill Road to get to the same spot as they do currently, or you could just split early and send them up 236th.

      I’m doing okay on the hill, climbing at 230-250 watts, which is my sweet spot these days. I finish the climb, pass the always confusing Union Hill Road intersections, climb some more, and then finally climb a bit more until I reach Novelty Hill road, where the century route turns left.

      Sigh. I will at times take a group down Novelty, but there’s a lot of traffic, there isn’t a great shoulder in places, and there’s a roundabout. All of that to get down to the valley so that you can ride Avondale North for a few miles.

      Ick. I turn right, head east a bit, and turn left on Trilogy Pkwy. This descends, turns west and changes to NE 133rd, and then descends all the way down into the valley. Good pavement, light traffic, and it rejoins the route on Bear Creek Road. I turn right and head north, when the road turns left I follow the ride route and head north, and then when the road ends at Woodinville Duvall road, I do a quick left/right so that I can get on Paradise Lake Rd and head north.

      You may have noticed a theme for this section, that of “heading north”.

      I generally prefer to ride PLR the opposite directly where you lose elevation and feel like you are stronger than you really are, but this direction is mostly okay except for the one 14% hill. Near the end I skip the little loop that would take me to a food stop on the real route, cross 522, and turn right to head North. The parts on the Sammamish Plateau and the Trilogy section were mostly sunny and I was mostly warm, though the descents got a bit chilly. Once I started heading north, it got cloudy and I picked up a headwind, which puts me just on the cold side of chilly. Nothing to do about that but keep riding. A nice section of Fales road takes me more north, and then finally hit the northernmost part of the route, and thankfully turn right to head to the south.

      I have a bit of mental myopia about this section of the route; I think that it’s quick to get from up here down to Fall City, but if you look at the route is around 32 miles. I also think that this section is flat, but only the section south of Carnation is flat; the rest is a seemingly endless succession of rolling hills. That can be fun if you are in a nice group and your legs feel good; not quite so fun when you are by yourself and your legs hurt. Two notable events occur on this portion.

      The first is that I come up and pass a group of 4 riders, ask them how far they are riding, and they say they are doing 90 miles. The second is that as I start to get close to Carnation, I’m on a small downhill and my bike is making a strange sound; the front derailleur is making a rubbing sound.

      That sound is familiar to most of us, buy my current bike never makes that sound, but it has Di2 electronic shifting and the front derailleur auto-trims so that it doesn’t rub. I look down and realize that I am cross-chained; I’m on the small chainwheel up front and the second-to-smallest sprocket on the cassette. This is generally not a good idea as it is less efficient and if you put a lot of force in you can break the chain. Further, it should not happen as I run my system in synchro mode where it will auto-shift the front when necessary.

      I figure it’s a glitch and I manually shift the front. Nothing happens…

      Those of you with Di2 probably know exactly what is going on, but for the rest of you, Di2 is a great system but it does run on batteries. The battery lasts quite a long time, but if you run it down too much, it stops shifting the front derailleur so that a) you will notice that the battery needs to be charged and b) you will be in a mode that preserves the low ratios for riding home.

      This is both annoying and glorious. Annoying because it means I can’t really spin more than 21 or 22 MPH on the gear that it gives me, and I really like to spin on descents to keep my legs warm, especially on a day like today. And glorious because it gives me a wonderful excuse to skip the Snoqualmie Falls climb so that I can get home and recharge it before it stops shifting at all.

      Soon after this happens, I roll into Carnation, hit 53 miles, and stop at a food mart for a bit of a break. I grab a Coke Zero – for the caffeine and the hydration – a snack pack of pepperoni and cheese, and small package of beef jerky. I sit in the sun on the curb and rest my legs.

      Even just sitting here, they hurt. After 10 minutes or so, I’m done with my food and I head south out of town, stopping by the ball field for a quick nature break.

      Then it’s across the valley to the west side and onto the West River Road, so named because it runs on the west side of the Snoqualmie river. This potentially could be a nice section with a nice river view, but in actuality you can’t really see the river at all, but there is lots of farmland and such to look at if you are into that sort of thing. I’d been hoping to make some time on this section, but a combination of a lack of gearing and a headwind slows me down a bit. It’s a relatively short section, and before I know it I’m at an intersection of with highway 202 and the base of the Fall City –> Issaquah climb.

      When I first started riding this was a very hard climb for me; it features something like 450’ total and some short sections in the 14% range. These days, even with 60+ miles in my legs and not feeling great, it’s just not that hard. The country repaved this with some gloriously smooth pavement last year and I had a really nice ascent after that – my last smooth ascent, it turns out, since they decided to put chipseal on top of that gloriously smooth pavement. I’m assuming this costs less in the long run but makes the climb much less nice.

      My ascent is pedestrian in terms of performance though not in terms of method of locomotion, I descend and then start up the “bonus” part of this climb. I’m thinking a bit through this section as I need to make a decision. I have three routes in my head to get home. I can stick on the century route which will take me a bit northwest and then down 236th – a street that was fine 15 years ago but is way too busy for a ride like this anymore (yes, I can’t stop complaining about the route). I can turn left on Fall city Issaquah road and either descend all the way down or take Black Nugget road down for the last part. Or, I can turn left off of fall city issaquah, ride up to the Highlands, and then descend into downtown Issaquah. I opt for the last one, and it’s mostly okay. My legs have been hurting a bit less since I had the snack & cold beverage.

      Now, all that is left is to climb all the way up Newport and then head for home. I’m trying to figure out whether I will hit 80 miles for the ride. I think it will be close.

      This next section is really too boring to talk about, but eventually I make it home pretty near to 82 miles and head inside to have some lunch.

      Overall, a pretty decent ride, delta the leg pain.

      Stats:

      Distance: 81.13 miles
      Time: 5:31:27
      Speed: 14.7 mi/h
      Up: 4437’
      Work: 2997 kJ (read this as “2997 calories”, it’s close enough).

      Food for the day:

      • 3 scoops of SuperStarch + 1/4 scoop of Endurox, 325 calories
      • 42 Cheez-its (+- 7 its), 275 calories
      • 1 Coke Zero flavored brown water with caffeine, 0 calories
      • 1/2 Honey Stinger chocolate waffle, 80 calories
      • Cheeze & pepperoni snack, 150 calories.

      I think that’s 830 calories total for the day.

      Strava link.

      And yes, I’ve made you read the whole thing for an explanation, but the US/Canadian exchange rate is about 0.8, so riding 100 Canadian miles is equal to 80 American miles. Hence “Canadian Century”.


      7 (11) Hills of Kirkland 2018

      Before or after you read this, I recommend watching the Relive video of the ride. Hell, you should probably do that instead of reading this…

      I have done 7 hills more than any other organized ride. Way more than any other ride; I think I have ridden nearly every year since 2005.

      As I got ready for yet another trip around Kirkland and points nearby, I was thinking about why I like this ride so much. And I think it’s a number of things:

    7. It’s short. In the early days, there was only the 38 mile route now known as the “classic”. These days I always ride the metric; for a couple of years I signed up for the full century and then found *really* good reasons to only ride the metric, so I’ve just decided to stick with the metric.

    8. It’s hilly. In the days before I got stupid and thought up Sufferin Summits, it was a really hilly ride, but these days it’s just moderately hilly. But in manages to throw in some nice challenge hills; Seminary and Winery. I do better on routes with a lot of up and down as they bother my neck muscles less, and the route that it uses is exactly the kind of route that I use for the rides that I lead.

    9. I could ride it in my sleep; the route is engrained in my brain and I know the area extensively, which means I have zero concern about getting lost or taking a wrong turn.

    10. It’s a fundraiser for a charity that I like.

    11. It’s the first organized ride I do every season.
    12. Those were good enough reasons in the early days, but early in this decade I added a new reason; my mother passed away early in the morning before a 7 hills ride after a long illness. I’ve found that when I’m in my “long ride” mental state, I can spend a little time remembering her and somehow it just works well.

      In 2017 I skipped 7 hills; I’m going to claim that it was weather-related, but I was in the middle of transitioning from a carb-fueled athlete to a fat-fueled athlete and not in great shape. I now have near a year of a different diet under my more-loosely-fitting belt, and I’ve been able to be more consistent in my training this spring. I’ve also been trying to make my easy rides easier and my harder rides harder.

      How will 2018 fare? My tentative plan for the upcoming months is to do a century (was going to be Flying Wheels but I have a conflict so it will probably be a solo one), Tour de Blast (which did not go well last year), DORMAR (a self-supported backwards RAMROD), Sufferin’ Summits, and then probably Passport 2 Pain in September. That’s a lot of rides, and I’m hoping my fitness coming into the season is good.

      Planning

      I signed up for the metric. And… well, the night before I pulled a neglected bag of cheez-its and a honey stinger waffle out of my old carb-fueled bike food store and set them on the counter. I don’t eat this stuff at all in my normal diet any more, but as I mentioned, I have some long rides planned, and while I can do 45 miles without food, I don’t think I can do 150. Which means I need to experiment a bit with light carb replacement during rides.

      The morning of

      I wake up at 5:30 to the sound of the birds outside, and quietly get dressed. Then it’s out to the kitchen to… well, not to do much of anything. I’d normally eat bacon and eggs but they take a long time to digest, which requires a lot of blood supply, which means less blood for your muscles. So, I sit around, do a bit of stretching, and try to figure out what to wear. I will be wearing my limited edition Sufferin’ Summits Jersey, that is for sure.

      The forecast is annoying. There is little chance for rain – which is great – but the starting forecast is for 55 at the start and maybe 63 at the finish. Which puts me in a quandry; above 60 I don’t need any covering for my arms or legs – maybe just a vest to wear at the start – while at 50 degrees I need arm and leg warmers. The expected temps are precisely at the transition between the two, which makes it maddening. I throw on arm warmers and leg warmers, get all the rest of my stuff together, and head out and load the car.

      Well, that’s not quite true; I’m not going to do this ride totally fasted. I mix up 2 scoops of Superstarch – a cool time-release glucose source – with a half a scoop of Endurox to make it slightly more palatable in a glass of water and drink it down. That will support my glycogen reserves during the ride but won’t provide a quick enough does of glucose to bump my insulin up and interfere with fat metabolism.

      The ride

      The start is pretty much like any start. I ditched my leg warmers due to the peer pressure of all the cyclists riding past me without them and had to make a trip back to the car to retrieve a forgotten water bottle.

      I generally only ride with people on this ride who I happen to meet during the ride, but my friend Mike is there and we start together, taking a quick detour to make sure that we ride through the inflatable “Start” arch, because if you don’t the ride doesn’t count. We ride along and talk as we make our way up Market (hill #1) and Juanita (hill #2), and then turn to descend down Holmes point road. This is a really fun descent normally, made a lot less fun this time by a lot of riders and car traffic, so we settle for a safe yet far less exuberant trip down. Which brings us to the base of hill #3, Seminary road.

      This is a decently hard climb at 414’ and a max gradient of 13% or so. I send Mike off ahead and tell him not to wait because he’s a much faster climber than me, and settle in. This is the hill where first-time participants realize that maybe this ride is a bit harder than they expected, so there are a lot of people riding pretty slowly. My legs feel good and I’m climbing at around 250 watts, a decent pace for me. I pass a lot of people and get passed by a few, and I hit the top faster than I expect. Seemed easy. A short break to take off my jacket and a quick descent and portage to the next hill.

      Norway hill is a nice little climb; a bit of undulation to keep it interesting and about as long but not quite as steep as seminary. I ride kindof conservative but there’s a group of 4 behind me that I don’t want to catch me, so I put out a bit more power in the top half, including a short section at over 300 watts. My legs feel pretty good, and I ate a few cheez-its on the way up that are sitting pretty well.

      We now get into what I think is the worst part of the ride. Part of that is just the geography; we need to get from Norway (hill #4) to Winery (hill #6), and there aren’t a lot of great route options. They also need to fit in a food stop in a parking lot near the hospital. I stop long enough for a nature break and to grab a small Clif bar (barette?), blueberry something something flavor.

      I haven’t talked about hill #5 because it doesn’t really exist; there’s a little climbing before the rest stop, and little climbing there, and that’s what we call hill #5. They used to use a slightly different route that had a slightly more defined hill, but even then it wasn’t much of a hill.

      We’re heading north now, we have a nice descent down brickyard road that is slightly marred by too many cyclists, and then curl back south on a mostly flat portion of the ride through the Woodinville winery district. People try to fly on this section for some unknown reason and I get passed by a few, but its far better to rest the legs a bit because of what is coming up.  I finally arrive at the base of hill #6, which if you were paying attention you already know is Winery Hill. At only 307’ of total elevation gain, it’s not a particularly long hill, but it is a nasty hill, with a 17-18% pitch at the beginning, and some slightly-less-nasty pitches later on. Kindof a set of stairsteps.

      I arrive near the back of a group of 25 riders or so, and start climbing. My legs feel good, so I ratchet up the effort and am climbing at about 500 watts through the steep section. As I’m picking my way through a clot of riders, some smartass in the group says, “remember, you paid to do this”.

      Okay, so, you might be able to guess who the smartass is…

      The hills flattens for a bit and I catch by breath, go hard up the second steep section, and then hard up the third steep section, and then try to maintain a decent pace up the long steady section, and I’m at the top, riding hard and turning left past the bagpiper towards the next part of the ride.

      Wait, the bagpiper?

      Yes, 7 hills has a bagpiper who stands at the top of Winery hill and plays. It’s another reason I really like this ride.

      A later check of my data shows that I cut 17 seconds off of my PR for Winery Hill, which makes me feel pretty good. I am even happier to note that I share 527th place on the climb with my friend Kent, who is a way better climber than I am.

      I make a quick stop at the next rest stop to top off my water and eat approximately 1/8th of the clif bar.

      Decision point…

      After you descend back down into the Sammamish River valley – the one you just climbed out of – you reach a decision point. You can go straight, do one final hill, and be done. Or you can turn left onto the metric century route.

      I turn left, and we head across to to the east side of the river valley and start up what I call “the 116th surprise”. It’s only about 50’ of elevation gain, but it makes up for it by being in the 15-16% range. Surprise. That makes me happy because a number of my routes features surprises, and the cyclists who ride with me always expression their appreciation. My unexpectedly strong legs carry me past another clot of riders and I turn off to finish the rest of the climb up education hill. Or partway up it.

      I feel a special bit of ownership around this part of the route. The route we used to do involved a descent down a 15% + hill that ended at a stoplight on a fast arterial. A few years ago it was a bit wet when we did that descent and the combination of wet brakes and a little sand at the bottom made it more terrifying than usual. I suggested an alternate route to the organizers, and we’ve used that route since.

      Next up is Novelty Hill which at 515’ is the biggest elevation hill we will climb today, which I guess is a bit novel. Beyond that, it’s not particularly steep (10-11% tops) and has no unique scenery. It does feature lots of vehicular traffic flying by at 45-50 MPH, though to be fair the shoulder is pretty good. I talk with one of the official support riders – the sweep for the century riders – on the way up for a minute or two before deciding to leave him up behind. We’re doing a loop in this section with a stealth hill or two, but it’s mostly boring. I play leapfrog with a couple of guys that I will refer to as “Chris” and “Scott”, because for some reason I am convinced that I actually remembered their names, and we are soon descending back down Novelty Hill.

      On the way down we will see a long line of riders ascending the hill, which makes me happy I am not them, but I wish them luck. My attitude towards the ascending riders is considerably more charitable than my attitude was towards the descending riders I saw on my ascent.

      We turn off on a chunk of Old Redmond Road that time forgot for hill #9. At 174’ and no more than 8%, it’s a short and easy one. As we’re rolling along “Chris” says, “it looks like we’re riding about the same speed, we might as well ride together” and introduces himself and Scott. We ride together and talk for about 90 seconds before “Chris” says that he needs to slow down for Scott – who is not having a good leg day – and I ride off ahead alone, completing the shortest spontaneous “let’s ride together” segment that I have participated in.

      After a quick descent, I am faced with a second trip up Education hill. It’s what I like to refer to as “re-Education Hill” as it’s the second time we climbed the hill. I like to refer to it that way, but it’s pointless to do so because I am all by my lonesome at this point. I can’t see any rabbits on the hill – a “rabbit” being a rider in front to try to catch up with, not the plentiful real rabbits that you hope will stay away from your wheels – so I check my internal store of motivation and find that while the gauge is hovering near “E” and the light is on, there is still a wee bit left, and I call on that to head up the hill to the tune of 220 watts or so. I am getting a bit tired.

      At the top, I hit the last rest stop. They specialize in utterly pedestrian turkey and cheese wraps, and I eat about half of one, another 1/8th of the Clif bar, and maybe a few more cheez-its. A volunteer gets me a water refill, I take a quick nature break, and then sit down in a chair. After 30 seconds, I realize that if I sit longer than that, I won’t want to move – as evidenced by the 3 guys in the chairs who haven’t moved since I got there – so it’s back on the bike. I descend back down to where the metric route branched off and get on the main route to the finish.

      This part is going to be fun. Partly because it’s hill #14 – and therefore the last one – and partly because I will have plenty of rabbits to chase on the climb, as the classic route riders are on the route for me.

      We are climbing the more popular part of Old Redmond Road, and it will take us 391’ up, but even the steep sections aren’t very steep. I go hard up the first pitch and barely make it over the crest without blowing up. The rest is mostly easier, until I finally turn left onto 132nd, and my climbing is done for the day.

      In this section the traffic lights break the riders into clumps, and I’m at the front of my clump and therefore have no visible rabbits. Except maybe one I can vaguely see way ahead of me. I ride down a short hill, turn left onto 116th which is mostly downhill with a few false flats, head down Northup which is fully downhill with no false flats, passing a few people, and then we turn onto Lake Washington Blvd for the final run to the finish. There’s a triathlete in front of me that I half-heartedly – for I only have half a heart left – try to catch going up a small little hill, but it doesn’t work, so when we get to Carillon point (yes, there is an actual carillon involved) I throttle back and spin along the waterfront to cool my legs down. Overall I feel pretty good; my legs are tired because I pushed them hard but I feel fairly strong and could keep riding.

      Then it’s onto the finish line festival and a somewhat perplexing set of booths, I get my strawberry shortcake (another reason to do the ride), eat the strawberries and whipped cream and a tiny part of the shortbread, and then hop back on the bike to ride back to the car and go find some lunch. Which turns out to be a Qdoba taco salad.

      Strava route

      Stats:






















      Miles 61.91
      Time 4:22:55
      Up 4,462’
      Work 2449 kj
      Speed 14.1 mph

      That’s a pretty good effort for me, though its a bit slower than I have done in the past.

      For the day, I had my two scoops of superstarch (about 200 calories), approximately 27 cheez-its (150 calories) and about 1/4 of a clif bar (50? calories), for a total of 400 calories. Oh, and the wrap, for maybe another 100. That was enough to keep me going strong for the whole 4.5 hours, which means that the majority of the 2450 calories I burned came from fat. My stomach felt great.

      No breakfast means I had a calorie deficit for the day of something over 3000 calories, and I’ve been doing my best to eat that back since.








      Bespoke bicycle Holder

      My nice bicycle currently hangs on two old shelf standards that are screwed into the wall, with some foam on them to protect the frame.

      IMG_9219

      It works, but the foam has seen better days and if we got a quake, it could easily shake off the ends.

      It’s time to build something a bit nicer, so I dug out some leftover hardwood plywood I have (maple, I think) and spent a little time with Fusion 360, and came up with the following design:

      image

      This is a render in oak. The holes are 16” apart so they can screw directly to the studs, and the hangers are a bit closer together so it’s easier to hang the bike with batteries on it. The arms that hold the bike have two hefty tenons that stick all the way through the back piece.

      Off to the garage to use the Shaper Origin…

      Cutting

      The cutting mostly went pretty well, but it took longer than I expected and I worked past a point of being too tired and therefore had a couple of issues. I’m using a piece of maple plywood that I had lying around that is unfortunately not very wide, so I had to put some auxiliary pieces off to the side with shaper tape on them so that it could figure out where it was. This mostly worked, until I got to the last cut on the last piece, and partway through I bumped my setup and that piece – which was partly clamped but not correctly clamped – moved.

      That is *bad*; the shaper throws up a big banner that says “the markers have moved and you are SOL”, or words to that effect. I tried a cut after that, and they were right, so I finished cutting through with an abrasive disk on my dremel and cleaned up with a little sanding drum.

      A little sanding, and it was time for gluing and clamping. The nice part of the holes and tabs approach is that there is a ton of surface area, so lots of material for the glue to grab onto. It’s probably strong enough with the glue because of the way the geometry works; the arms that hold the bike can only pull straight out, and even that is difficult. So, no fasteners required, but a lot of clamps.

      IMG_9217

      Give it 4 hours for the glue to set, and we are left with this. The dark coloration looks like a burn but is really just the plywood.

      IMG_9218

      Overall, it came out mostly okay; in some places the fit isn’t as tight as I’d like – which I attribute to some wiggling because of how I did the cutting – but it’s more than functional.

      Four 3” screws to mount it – yes, that’s overkill, but it’s so easy with an impact driver…

      IMG_9221

      and we’re done. I’m hoping the sunscreen shelf will help remind me to use it before I leave. I used some short pieces of the foam from the old holder to pad the new one.

      IMG_9222


      Down 20?

      (Authors Note: This is the fourth time I’ve tried to write something like this, but it kept getting *way* too long and detailed. I’ve kept it simple this time, but that means I’ve left out a lot of details, some of which are surely important. So ask if you have questions…)

      It started with the candy dish…

      Early last spring, due to show reshuffling, my team ended up in the same room as our admin – which was fine – and in the same room as the group candy supply – which was not.

      It was a bit better than my previous team – which maintained what was officially known as “the candy wall” – but the problem was that the candy dish was at the entrance of my room, so was really easy to come back from lunch, grab a few “fun size” pieces, and eat them at my desk. There’s some interesting research in psychology that says that one of the best ways to get adherence is through random rewards, and our candy dish implementation had that; you might not really be hungry for a Reeses ™ peanut butter cup, but if you see one, you better grab it before somebody else does.

      The whole “work food” culture is pretty horrible when you think about it.

      I am lucky enough to have good genetics when it comes to keeping a decent weight, but the extra candy bumped me up from my long-term “fighting” weight of 173 to 178, and I was feeling really tired and crappy in the afternoons. The first did not bode well for the upcoming cycling season, and the second did not bode well in general.

      At the time, I was on a low-fat diet, which is the kind of diet they tell you to be on. And I’d been doing a bunch of reading about glycemic index and glycemic load, and wondered if that was having an effect. Clearly, the candy was high glycemic index, but was there something in my lunches that was contributing to me craving candy?

      So, I started an experiment. Instead of the sandwiches that I ate at lunch 3 days a week (because they were cheap) and the burritos that I ate the other two (because burritos), I switched to salads with meat three days, and burrito bowls without the rice and tortillas the other days (because burritos).

      It was a pretty simple change, but it had a pretty immediate impact; I still habitually wanted candy (because candy), but I didn’t crave it as much, and I could cut down how much I ate. And I felt much better in the afternoons, which was good, but did not convert them to an endless series of rainbows and unicorns (a guy can dream, right?).

      Anyway, that led to a whole lot of research into nutrition, which led to research into biochemistry, watching a few lectures, and reading a lot of clinical research.

      But I started by trying to answer a question that had always confused me:

      Why is it so damn hard for many endurance athletes to lose weight?

      Some of the cyclists I know are very thin and light, but I know others – many that ride a *lot* more miles than I did – who carried maybe 40 pounds more than they would like to. I knew what worked for me – making sure I controlled my blood sugar well after long rides – but that still required a fair bit of discipline to get me to light, and I never got to “cycling light” – that weight where your cycling friends are annoyed at how little you weigh. That was true of most cyclists I knew. My trust power meter said that I was easily burning 4000 calories per week.

      Why wasn’t all of that exercise translating to weight loss?

      Looking at the clinical studies about exercise and weight loss, we see mixed results. Aerobic exercise works in controlled situations – where the amount of food is controlled – but doesn’t work well where people choose what they eat. There are two hypotheses for what is going on; the simple one is that people are hungry and just eat the calories back; the more troubling (and luckily, probably rarer) one is that exercise under caloric restriction can reduce the base metabolic rate for some people.

      To lose weight, eat fewer calories or burn more

      This has been the mantra for weight control for over 40 years, and it’s what I used to believe. It’s simple to understand, but  doesn’t work very well in practice.

      The problem is that it considers all calories to be the same. But when we are talking about body weight, we don’t want to lose weight, what we really want to do is to lose *fat*. So, let’s recast the statement:

      To lose weight, live in a way that minimizes the amount of energy that is put into your fat stores, and maximizes the amount of energy that is pulled out of your fat stores.

      So, I started looking more closely at how fat accumulation works in humans – what drives calories into fat stores, and what pulls calories out of fat stores.

      I originally had a long and technical discussion on what controls energy partitioning – where the energy to run your body comes from – but I am unable to make such a discussion brief, so here’s the simplified version:

      1. The amount of fat you burn during day to day living is tied directly to the percentage of carbs that you eat. Eat a lot of carbs, burn a little fat; eat a few carbs, burn a lot of fat.

      2. The amount of fat you burn during exercise is tied both to the kind of diet you eat and your energy state when you exercise.

      The key point is that both of these are adaptable behavior; our bodies can adapt (mostly) to different mixes.

      The result of this is that two riders of equal fitness can go on the same ride, both burn 1000 calories, and burn *vastly* different amounts of fat. If you want to look at some pretty graphs that illustrate this, go read this article and this article from CyclingTips.com.

      Back to the experiment…

      Back in real life, I expanded my experiment a bit. My breakfast went from a big-ole bowl of cereal with a lot of milk to a small bowl with minimal milk and a hard-boiled egg. My dinners lost a few of their carbs.

      And I was down about 5 pounds, back to the weight that I wanted, with just some small changes.

      At this point, I really didn’t have many carbs in my base diet – and they were increasingly low-GI carbs – but I was still using Skratch on my rides, and I was still using Endurox after my rides; following my traditional fueling strategy.

      So…

      I forgot to mention another motivation that got me playing around with diet. My on-bike fueling strategy did not work very well. Thankfully, I rarely got the “GI distress” that some people do, but on longer rides I know that I’m going to get some stomach pain from the skratch, and I’m going to have energy issues. That makes rides like RAMROD a bit of a crap shoot; at best I felt sort of blah, but generally I felt a few rungs below blah.  

      The next experiment was obvious: I put the Skratch in the back of the cupboard, and started filling my bottles with water. I put some cheez-its (carbs + fat + protein) in ziploc in my pocket, added a packet of sport beans just in case, and I started riding.

      And that mostly worked. I felt a little under on power, but it was early season and I’m under on power then anyway. I sometimes supplemented a bit with the aforementioned cheez-its in the middle of the ride.

      About this point, I weighed myself, and the scale said 169. I checked another scale to be sure. I hadn’t been this light in 20 years, not even in 2005 when I rode *way* more miles I ride these days. And I was eating what I thought was a lot of food.

      Hmm…

      Somewhere in here, I came across a post by noted cycling coach Joe Friel in which he talked about how he got back down to his “racing weight”, which aligned well with the research I had been doing, the biochemistry I learned, and my experimental results.

      And I thought, “What the hell, let’s see where this thing ends up…”

      Heresy

      I own a copy of “food for fitness”, and a copy of “the feedzone cookbook”. I’ve read all the recommended diets for athletes, and they all recommend a diet high in complex carbs – something like 60 or 65% of calories.

      I decided to go full keto, and see what happened. That means <50grams of carbs per day (though I never actually counted), quite a bit of protein, and more fat. Since I had eased myself into a lower carb diet, the transition was pretty easy (this is not the case for a lot of people), and about a week later, I headed out on Saturday morning for a nice 45 mile ride.

      The first 45 minutes was great; I felt strong, had good power. And then it happened; over the space of about 15 minutes, I ran out of carbs.

      If you’ve bonked, you know what this is like, but this time it was different. I actually felt okay, my brain was fairly clear. I just lost all ability to put power down. You know the Tour de France rides where the guy’s bike breaks and he picks it up and throws it into the bushes? I was close to that. I cut the ride short, could barely push 150 watts the rest of the way home, and regrouped.

      After talking with a few people and doing some more research, I realized that while I was pretty fat adapted for regular life, I was not fully adapted for cycling. So, I kept at it. I did Tour de Blast (6000+ feet of up over 80 miles), felt good at some points and awful at others, bad enough I had my wife pick me up at 70 miles. But the overall trend was positive; I could do my Tue/Thu night rides (35 miles, 2000’ of up) *easily* on just water and feel good at the end. And my high-end power was just fine; one night I out-sprinted one of our race-team guys and did over 1000 watts for about 9 seconds, which is pretty decent for me. The only point of concern I have is the high aerobic range; I don’t think I quite have the pep I used to have there, but give that I made this change right at the beginning of the season (stupid) and didn’t do the kind of high-intensity training I would usually do (lazy), I don’t know how much is a dietary effect and how much is just a lack of training.

      And then finally, near the end of the summer, I did my own supremely stupid ride, Sufferin’ Summits. 9500’ of climbing over 55 miles.

      I did it fasted, and over the 5 hours it took (did I say it was hilly?), I had two servings of a really cool time-release glucose called SuperStarch – about 280 calories total, a bottle of diet coke, and about 14 cheez-its. After dragging myself up the worst hills I know of in the area, I finished the ride.

      And I could have kept going. Honestly, I felt pretty good.

      During the weeks before the ride, my weight continued to drop, and finally the numbers clicked over to 158, which is pretty much where I am right now. I lost two inches off my waist (34 –> 32, my college size), and I lost a ton of subcutaneous fat.  I have a tiny bit of fat remaining around my waist, and I think this spring I might see if I can drop down to 153-155 or so. From what I can tell I *mostly* preserved muscle mass, but since cyclists tend to have the upper bodies of 80-year-old French grandmothers, I have been spending a bit of time in the weight room.

      So that’s the story. Down an honest 20 pounds over 4 months.

      Guidance

      I went as far as I could – heresy, right? – to see what would happen, but there are a lot of variants of low carb. Some athletes do less strict diet variants like Paleo, Primal, or slow carb. Many aim for a higher level of carbs; something like 100 grams per day. A few are very strict on carbs during training but carefully use gels and other simple sugars during events. Some do a complex cyclic protocol. Some do it as a weight reduction approach during the off season and switch back to a moderate carb diet during the bulk of the season.

      There are a lot of options, which is good, because there isn’t a lot of research in this area yet (and I’m not sure who would pay for research; certainly not the exercise drink folks).

      As I said at the beginning, if you have questions, please ask me.


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