Within the Faculty of Physical Education at the University of Alberta there is a group of people studying the effects of hard exercise on inflammation in the lungs (following exercise, not during it, but I’m not doing the study so don’t ask me). Participation in these kinds of studies is of course voluntary and you don’t get paid. You do however need to pass a VO2 test to qualify as “fit enough” to participate in the study. A VO2 test is supposed to be the best indicator of aerobic fitness, unfortunately it’s not easy to do, typical lab testing costs about $120 a pop. That’s not exactly student pocket change. So I signed up, not because I have buckets of time, but because who wouldn’t pass up an opportunity to save $120 that I wouldn’t have spent anyways.
VO2 max is a measure of the maximum capacity to transport and utilize oxygen during incremental exercise. (The derivation is V̇ – volume per time, O2 – oxygen, max – maximum). It is also called maximal oxygen consumption or maximal oxygen uptake. It is also known as aerobic capacity, which reflects the physical fitness of a person. – The Stolen Definition from Wikipedia
If you do a VO2 test on a bike you basically start riding at an easy wattage and the required power for you to generate is incremented slowly until you die. That’s just about it, oh and the fact that you’ve got this huge tube down your throat and some girl yelling at you with instructions.
Above are some photos of the event, and the final one is the most important piece of the result. It shows a line plotting all of the measured points during the test and the ratio of carbon dioxide to oxygen over a short interval of time. What you see is that early in the test I am processing a low amount of oxygen somewhere around 0.5 L/min and as I increase the amount of oxygen I’m taking in (by cycling harder) the amount of C02 I’m getting rid of maintains the same ratio. That’s the case until I reach my aerobic threshold “wattage” or “effort” or “speed” and then the graph starts to kink. When that kink occurs I’m essentially firing on all pistons but not yet accumulating any oxygen debt or lactic acid in my muscles that I cannot get rid of. That measurement is worth a lot to an athlete if it is calibrated to a heart-rate. That’s why these fitness centers can charge $120 to get your VO2 max tested. Once you know what heart-rate you are at when you reach the threshold you can then measure your “arrival” at threshold without lugging around a computer and shoving a tube down your throat. Training at that threshold is the fastest way to gain aerobic fitness, basically it’s the recipe to get in the best shape in the most efficient way possible. For me the magic number is 170 beats per minute. Typically athletes can measure their maximum heart rate and then estimate this magic spot between 80% and 85% of their max heart rate or 75% to 80% of their reserve heart rate. These two estimates put my magic number in the domain of (163, 174) or (164, 172) correspondingly. Guess what? I follow the pattern, the number is 170.
So, did I qualify for the study? No I missed the mark by 2.8 ml/kg/min. “High calibre” athletes needed to meet the mark of 60 ml/kg/min and I scored only 57.2, not good enough. I still scored about 30% better than the average “non-athlete” (45 ml/kg/min), but it still feels a bit crushing. I have to say that my mass has got to be a disadvantage for something like this, if I were a dozen fewer kilograms like our buddy Lance Armstrong was things would be a different story. Since missing the mark I’ve done a bit of poking around to try and find a bit of solace in some non-standardization of the test. Indeed there is some floating around online, the test is said to be slightly biased towards the smaller athlete (which, at 196 cm I am not) by a fraction proportional to “the difference in masses to the one third power”. That means my inclination to loose weight and score better is right, but I think it also means that it is not really worth it.
Oh, and the other number that’s kinda cool is that I died at 520 watts. That’s pretty good power if I had to say so, and that’s following a 9 minute effort. I kinda doubt (as a matter of fact I know) I would be able to crack a mean grand in a track 1km sprint but the indication is that I’d be respectable, I can confidently say I’d be beyond 750. They say, but I don’t know exactly who “they” is, that to split 40 km per hour in a flat 40 km time trial (on a good bike with aero wheels), you need to stick around 300 watts on the pavement.