Before answering the question let me tell you more about these two variables. VO2max, also called “aerobic capacity,” is a measure of how much oxygen your body uses when exercising at a maximal effort for an extended period of time. It is typically measured with the athlete wearing a breathing apparatus that determines how much oxygen is inhaled and how much is exhaled. The difference is what was used by the muscles to produce energy. The more oxygen one can use, the more aerobically fit that person is. We know that the elite cyclists in the pro peloton all have quite high VO2max levels. Should we test all of the riders at the start of one of the Grand Tours I’m sure we’d find they all are at least at a level of 70 (milliliters of oxygen per kilogram of body weight per minute). The same would be true of the elite male runners at the start of last Sunday’s New York City Marathon. The elite women there would probably have tested about 10% lower.
If we did indeed test all of the pro riders at the start line of a bike time trial race and then ranked them from the highest VO2max at the top to the lowest at the bottom, how would that compare with how the race actually finished? Would the highest VO2max win the race and the lowest finish last? Not at all. This has been done in several different sudies and the research has found no relationship between race results ranking and VO2max ranking – among elite athletes. Does that seem strange? Frank Shorter proved a long time ago that it isn’t strange at all.
When Shorter was at the height of his running career in the 1970s his VO2max was about 72. That’s very pedestrian for a world-class runner. One his top competitors was Bill Rodgers who had been found to have a peak VO2max of about 78. Even though Shorter’s was 8% lower than Rodgers’ aerobic capacity, Shorter usually won when they went head to head. In fact, Shorter proved to be one of the top marathon runners in the world with Olympic Gold and Silver medals along with wins in most of the major marathons of the day.
Back in 1989 I was invited by a friend to go for a run with Shorter and Rodgers in Boulder, Colorado. It was the first time the two had ever run together in a workout. Running with Shorter on my left and Rodgers on my right it was quite obvious why Shorter was so dominant despite a rather mundane VO2max. He ran like water flowing downhill, like a cloud passing by. There was no excess motion. No wasted energy. He was the definition of smooth. Rodgers, on the other hand, could be seen out of the corner of my eye and appeared to be some sort of Victorian machine with flywheels, crank arms, pistons and steam engines. He oscillated up and down, his arms swung across and around his body, and one leg had a flail to it in recovery. Shorter wasted none of his 72 VO2max; Rodgers wasted a great deal of his.
You see, there’s much more to being fast than just aerobic capacity. At the elite level it’s just a “ticket to the club.” If you want to be an elite athlete you need to have a high VO2max. But that just gets you to the start line. To compete well you also must be economical like Shorter was and you need an anaerobic/lactate threshold at a high percentage of your VO2max. Shorter was undoubtedly excellent in this last category also. I’ve never seen any numbers on that for him.
Now back to our five teammates… You should be able to pick the TT winner by now. It’s Kevin, the one with the highest power output at VO2max. Given the choice of a high VO2max or a high power output at a lower VO2max, always pick power. It should be obvious that the person who can put out the most power when at his top end is the person who is most likely to win. There’s a close relationship between power and the results of a race. In the same way, if you know the paces a group of runner can do at VO2max you have the best indicator of how the race results will come out.
Running races and time trials are won by the fastest athletes, not by the athletes with the highest aerobic capacities. It’s like asking all of the runners at the 10k starting line in your age group what their best 10k times have been in the last 8 weeks. Assuming comparable courses, you can quite closely predict how the 10k race will finish. Of course, there will be a few minor variations due to motivation, race-morning diet, fatigue, injuries and a few other factors. Power on a bike is much the same. It’s a great predictor of performance.