A big theme of my training/this blog is individuality. It’s central to training a successful runner. The problem is that it is hard to do. It takes work to actually individualize something. It’s much easier to give a cookie cutter approach. If you know anything about research and studies is that most of the time they ignore the individual and focus entirely on the group. If you read abstracts or if you read papers, all the conclusions concern the average improvement in performance or certain parameters. However, if you dig deeper, does everyone improve in the same way? Well if you are a coach, the answer is an easy no. But let’s look at the research.

The study I’m going to go over is one by Vollard et al (2009) entitled “Systematic analysis of adaptations in aerobic capacity and submaximal energy metabolism provides a unique insight into determinants of human aerobic performance.”

In this study, they looked at the effects of 6 weeks of endurance cycling at 70% of the subjects VO2max in untrained subjects. They measured all sorts of data during a maximal test, a performance test, and a submaximal test, in addition to certain aerobic enzyme activity. They then compared the before and after results on an individual basis. Here’s what they found:

Given the same “training stimulus” the adaptations were all over the place. You had a range of improved VO2max from -2 to +30%. This not only happened with VO2max but with almost everything. And the high responders (the ones that improved the most) in VO2max were not the high responders in other things, same thing with low responders. This means the ones who didn’t improve at all in VO2max had huge improvements in other parameters. The changes varied all over the place with enzyme concentration, submax HR, submax lactate, performance, resting glycogen, maximum work capacity, creatine phosphate, and a whole host of things. What does this all mean and what are the key findings?

-The change in VO2max was not related to the change in performance. That means how much the VO2max changed didn’t correspond to how much performance improved.

Let’s look at some of the author’s conclusions:

-“ VO2max is often presented as a critical determinant of aerobic performance, yet we demonstrate that training-induced changes in VO2max and aerobic performance are not related even in untrained subjects”

-“ we demonstrate that VO2max and aerobic performance associate with distinct and separate physiological and biochemical endpoints, suggesting that proposed models for the determinants of endurance performance may need to be revisited.”

– “Although the overall stimuli for improving aerobic capacity and aerobic performance are identical (i.e., aerobic training), we demonstrate that these adaptations do not occur in proportion to each other and do not appear to be determined by the same physiological or biochemical parameters.”

– “First, standardizing training intensity to a set percentage of VO2max in training studies aiming to study aerobic performance will result in large interindividual differences in the magnitude of the training stimulus (see Figs. 1 and 5). Second, the use of set percentages of V˙ O2max in studies investigating metabolic responses to exercise will also produce large interindividual variation. Finally, in studies determining changes in aerobic performance using time trials to exhaustion at a set percentage of V˙ O2max, the metabolic response to exercise of individual subjects may vary considerably, potentially affecting any changes in performance measured or the underlying nature of fatigue (49).”

-“the present study demonstrates that VO2max cannot be considered a universal parameter to standardize aerobic exercise training studies. Based on the present data we conclude that plasticity of VO2max is a poor determinant of improvements in aerobic performance in healthy young untrained males.”

So, what does it REALLY mean?

-The assumption that we often make that an improvement in VO2max=improved performance is wrong (This is backed up by other studies too). So, why does some training focus on improving a parameter that (a) doesn’t change in elites and (b) doesn’t mean an improvement in performance?

-The use of %VO2max to base training off of is garbage. The stimulus varies completely depending on the person, even in groups of very similar people. This begs the question of why we try and do it. Take a look at USATF guidelines or Vigil or Daniels. In addition, all the research does it, which might explain why the research does not match up with real world experience!!

– We do NOT know as much as we think we do. We can’t explain fatigue and performance yet. Quick lesson, we base things off of what we can measure. As a consequence, the most important things become variables that are easily measurable. Why is VO2 used so much? Because we could measure it in the early 1900s which led to a lot of research on it. Thus it formed the basis of our knowledge. Another example, why is lactate considered evil even though it is not? Because we could measure it early on when we couldn’t detect what else was going on in the muscle. Thus it gets a horrible reputation…poor lactate.

-Aerobic capacity and aerobic performance are NOT the same things.

-Individuals will respond differently to a similar stimulus based on their physiological and psychological makeup. It’s why fast twitch guys can improve threshold by doing short reps at 2mi-5k pace, while an endurance guy might need 30min total at half marathon kind of a pace. Or to tie it into a recent topic, its why some people need 10mi while others need 5 and 5.

-This really calls into question the efficacy of using %of VO2max or in other terms vDOT charts or whatever you want to use. Can we just stick to race paces and variations of individuals race pace?

Conclusions: Individualization. Think about the effect of a stimulus will have on the individual.

Get My New Guide on: The Science of Creating Workouts


    1. Anonymous on November 3, 2009 at 11:09 pm

      Good job on your road races. It is nice to win and get some cash too. How is the asthma? Hope your HS kids do well and interesting stuff on the blog Steve.

    2. Anonymous on December 1, 2010 at 10:16 pm

      Surely this is exactly why Daniels defined VDOT. He knows VO2max is hugely variable for any given running ability, so he sets training paces as a percentage of your current pace.

    Leave a Reply