Ketogenic diet - okay for top athletes?

Discussion in 'Dieting / Supplement Discussion' started by repsakv, May 22, 2018.

  1. repsakv

    repsakv White Belt

    May 22, 2018
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    You hear so much about the ketogenic diet and how much benefits it has. To be honest, it's too strict for me and i wont try it.
    But just out of curiousity, despite the hype it seems like top athletes are not adopting the diet. Why is that?
    Or am i wrong and does somebody know examples if athletes who are keto?
  2. beat...people...up?

    beat...people...up? White Belt

    Mar 5, 2018
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    If you dig deep enough into even those rare athletes who claim to be keto, you'll find they supplement with carbs during or around their competitions. (Even bodybuilders who keto diet to get to the stage often take in some simple carbs for muscle fullness day-of).

    You know how the body's energy systems work, right? So basically you have three types of activity:

    1. Purely anaerobic (relies upon creatine phosphate and is used in efforts of roughly 6 seconds or less)

    2. Anaerobic-glycolytic (relies on anaerobic glycolysis--meaning it does use glycogen, which comes from carbohydrate--medium duration of up to 2 minutes effort)

    3. Aerobic (ATP in this case can come from both fatty acids AND glycogen stores, depending heavily on intensity, so that you can burn more or less fat vs. carbohydrate for fuel; at lower intensities you burn a higher percentage of fat)

    It's #3 that is most interesting, because some endurance athletes have tested as using a huge percentage of fatty acids vs. carbohydrate as their energy substrate during aerobic exercise. If you are running/cycling/whatever at 70% of your V02max or below you can probably take in minimal carbs, for instance. But if you are putting forth a greater effort then you will need some carbohydrate for fuel as you'll tip into more glycolysis. This also depends very heavily on the individual. Some people burn more fat and some burn more carbohydrate during aerobic efforts.

    Interestingly, neither super-short efforts (creatine phosphate pathway) nor super-long efforts (low end of aerobic ATP synthesis) require [much] glucose. It's the ones in the middle (that anaerobic-glycolytic, or even HARD aerobic efforts that are, because they are hard, shorter in duration) that do need more glucose to accomplish. For instance, I don't think a mile runner would do well on a ketogenic diet because they are working at near-100% of their aerobic capacity--impossible to reach burning solely fat for fuel.

    Considering that most grappling matches are about 5-10 minutes long, they are indeed mostly aerobic. They are quite intense, though, and so most grapplers would do better with some carbohydrate as fuel. I don't think many people are at 70% of V02max effort or below in a tournament setting.

    Cyclical ketogenic diets are probably the most any elite athlete would do. AFAIK. I say this will likely be true EVEN IF they publicly claim otherwise.
    repsakv likes this.

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