AeT and VO2max

  • Creator
    Topic
  • #34382
    l.tregan
    Participant

    Hi,

    Sorry, I made a quick search on the forums and could not find the answer: if V02max measures Oxygene in – Oxygene out, how comes V02 max can increase (eg. quickly through interval for untrained athletes, then it maxes out ) but not the AeT ? Who is consuming this extra oxygen ? ^^

    This article for instance shows that for the same V02max, AeTs can be significantly different. https://www.ncbi.nlm.nih.gov/pubmed/3253234.

    Thanks,

  • Keymaster
    Scott Johnston on #34485

    MaxVO2 is analogous to your car’s engine’s horse power. By measuring the difference between O2 intake and O2 exhaled and using a method called indirect calorimetry a calculation is made that shows how much power you are developing. Whereas the car engine’s power is measured directly via a dynamometer. And like the car engine you can’t sustain max power for very long. Try holding your foot to the floor on your car and see how long that engine lasts 🙂 likewise we can sustain maxVO2 for just a few minutes before fatigue will cause us to shut down.

    In our books and in this article we discuss at some length why maxVO2 is a first wave adaptation and why it will increase rapidly in the young and untrained but often does not change and may even drop among elites despite performance gains. So I will not go into that here.

    MaxVO2 and AeT are not related to one another. I have trained and tested an Olympian XC skier with a maxVO2 of 92ml/kg/min but whose AeT was in the basement. As mentioned in the linked article and in our books maxVO2 has a rather poor correlation to endurance performance. How long you can sustain a high percentage of maxVO2 on the other hand has an almost perfect correlation to endurance performance. The ability to sustain that high % of maxVO2 is what we call endurance and it is highly dependent on AeT.

    Scott

    Participant
    l.tregan on #34555

    The part I fail to understand: above AeT, slow twitch fibers are maxed out and fast twitch fibers start to be recruited to increase speed/power. If so, why would VO2 increases past the AeT ?

    Surely I get something wrong – because VO2 increases more or less linearly until max HR.

    loic

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    Keymaster
    Scott Semple on #34634

    I’m not sure if it’s true that ST fiber is maxed out at AeT. That’s just the point where the ST/FT balance changes and more energy is coming from glycolysis than lipolysis. I suspect that ST fiber is recruited right up to maximum.

    But I was wrong once before… 🙂

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