The Science of Nutrition

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Hosted by
Scott Warr

Dr. Art Zemach and co-founder of Tailwind Nutrition, Jeff Vierling join The Nation to discuss Nutrition.

Dr. Art Zemach
Jeff Vierling

 

 

 

 

 

 

We talk about the Macro-nutrients carbohydrates and protein.

  • Types of Carbs – are they all created equally?
  • Does the body need carbs?
  • What about training your body to burn fat?
  • Why proteins?
  • Glycemic Index
  • The Golden Hour
  • How do macronutrients help us maximize oxygen utilization?

This week’s winner of the PATH Projects’ kit is John Knowles!

Join the discussion

4 comments
  • Great podcast, as usual. As a “fat adapted” ultrarunner and board certified cardiologist with an interest in metabolism and exercise physiology, I was confused about the discussion about The Golden Hour. I understand that this is a convenient time to use high glycemic carbs to replenish glycogen stores, but I still don’t understand why bother repleting those stores. If you are fat adapted, why not just continue to burn fat post workout? The answer on the podcast to this question was vague about possible irritability and decreased immune system function. Is there data to support that? On the contrary, post workout when glycogen stores are zero, why not leave them at zero and burn fat? This will induce a degree of ketosis, but isn’t that a good thing? Isn’t there data showing that ketosis has a myriad of other benefits?

    • Hi David,

      Thanks so much for you comment! You’ve brought up a really interesting point about muscle glycogen in fat adapted athletes. I don’t think this particular issue has been completely worked out, but I’ll try to answer it as best I can.

      As a fat adapted athlete, you have trained yourself to be more efficient at burning fat for energy, which can work to your advantage in ultra-distance competitions. This does not mean that you do not use muscle glycogen, or that muscle glycogen is unimportant to you. You still need and use muscle glycogen as a fat adapted athlete, and you have trained your body to create and replenish that glycogen using fat as an energy source, instead of carbohydrate.

      There is a lecture with information on this subject by Professor Jeff Volek from Ohio State University, here is the YouTube link: https://www.youtube.com/watch?v=tQbgdRoAfOo Look at the slide at 25:30, which shows muscle glycogen in low carb and high carb athletes before, after, and 2 hours after a 3 hour run. Note that both high carb and low carb athletes have essentially identical amounts of muscle glycogen before exercise, the same amount of glycogen depletion during exercise, and they replenish glycogen at the same rate after exercise. Note also that two hours after exercise, neither group has completely replenished their glycogen.

      So I would like to answer your question with a question: For high carb athletes, a fast acting carbohydrate, and the right selection of amino acids, can replenish glycogen more effectively during the “Golden Hour” after exercise, when insulin sensitivity in increased, but insulin secretion is no longer suppressed. Will that same strategy help a low carb athlete? In other words, as a fat adapted athlete, would it be to your advantage to use this strategy right after exercise, and then to return to your LCHF diet for the rest of the day? I think the answer lies in understanding how and why low carb athletes maintain and protect their muscle glycogen just as high carb athletes do, and I don’t think that has been completely worked out.

      Just as important for your training benefit as an athlete is the rebuilding of your skeletal muscle fibers and mitochondrial proteins. The gateway enzyme for the rebuilding of muscles, the enzyme mTOR, will not turn on until you have the necessary amino acid building blocks, and a good energy status. That is why it is important to have good energy status, and a complete protein, after exercise.

      As a fat adapted athlete you have become accustomed to living and training with small amounts of low glycemic index carbohydrates. Clearly those low glycemic index carbs are the best choice for day-to-day healthy living, whether you are a high carb athlete, a low carb athlete, or practice nutritional ketosis. However the first hour after exercise is a metabolically special time. Will you replenish your glycogen faster, and rebuild your muscles more effectively, by using a high glycemic index carb and a complete protein right after exercise, and then returning to your LCHF diet for the rest of the day? I don’t know the answer to that, but I think over the next year we’re going to find out.

      Regards,

      Art

  • I typically find these podcast interesting, funny, enlightening … but this one seemed more like an hour long infomercial, than an honest discussion on nutrition. I understand Tailwind has a new product and they’d like to promote it, but a discussion on nutrition should include the value of eating healthy, what foods are best for an endurance athlete during training, what foods to avoid, when/what to eat just prior to a hard training run or race. Just seemed to keep coming back to the value using a TW product during and after a race or hard workout. Love the TW product … just was looking for something more rounded on the discussion of nutrition.

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