sports & fitness
Dave Miller is a competitive cyclist and a graduate student in persuasive technology exploring how can technology influence behavior. He was interested in getting a VO2 Max test to access his potential. In this video, he talks about what VO2 Max is and why test it, and how much is determined by genetics.
So this is not me unfortunately; I couldn’t take a picture of myself while doing this so I borrowed it from somebody else, but basically it looks like this, where you ride an exercise bicycle with a computer that ramps up the resistance and you breathe through a tube, and it’s kind of unpleasant for about 15 minutes, and then you find out how close to the pros you could potentially be to some degree.
So there are two energy systems supplying your muscles. So you have an aerobic system, which is how much oxygen you can uptake that reacts with glucose and produces energy to fire your muscles and cause them to contract. Unfortunately there’s a breakpoint. So your oxygen can fuel your muscles until about this point here and at that point you can’t uptake any more oxygen and your lungs can’t move it into your bloodstream, and your bloodstream can’t move it into your muscles. And at that point you switch over to your aerobic system and start to fatigue. So within this region here, I’m producing lactic acid at a rate slower than I can metabolize it, and then once you reach your aerobic capacity you exceed your ability to metabolize that lactate and will fatigue much much faster.
So as far as the aerobic system – this is also not me, this is from a velodrome news article, my baseline would be somewhere up about here, but for the sake of having a nice graphic.
What happens, once you exceed your lactate threshold, you start to build up lactate in your muscles, and fatigue, and get that burning sensation and hopefully you will run out of road before you run out ability to buffer that lactate in your system.
Now, having two systems to provide energy you have some sort of balance that naturally determine and also determine by training. The aerobic system is more determined by genetics for most people. There is variability in how much you can train your aerobic system. The aerobic system is much more responsive to training and therefore that’s the good news, giving Alan where I wrote the article where I got this graphic from, he said he would bet on one with a mediocre anaerobic system and and a great anaerobic system in a race any day, which isn’t necessarily so good for me because as it turns out I have a relatively good aerobic system.
My VO2Max of 67.8 puts me in the range of elite men for club athletes. So I’m a cap four racer. There are five categories. Five being who don’t know which end of the bike to ride and one being the pro’s, so like five, four, three, two, one pro an in being the legendary pro’s with a VO2Max of 88. And the all-time greatest being 96 which is an Olympic Nordic skier. And his test was taken out of season and the doctor said that it is entirely possible that his end season which is a little bit over 100, which is quite impressive.
On the other hand there are untrained men with a VO2Max in the range of 45, and untrained women have a range 38. So there is a gender difference in aerobic capacity.
So 67.8 puts me up there with higher category cyclists, like my friend who was 68.3. he’s much fast, so he has a bit more will to win and a much better anaerobic system. But I’m pretty happy with my potential being better than I thought it was going to be.
So as far as to what this relates to in terms of my personal performance there are several break point. This is a critical power-plot from software called Golden Cheetah, which is also partially developed by a ITP graduate now. And in the bottom regions here, so zones one though three are almost completely running on the aerobic system. Zone four is sort of the transition, zone five, six, and seven are more towards the anaerobic capacity. And zone seven being almost entirely anaerobic. And you can see that that only will power you for about a minute and a half.
So as your power output goes up, your ability to produce that power at that level goes down. So I can produce as much energy as a horse for one second. The horse of course can produce 746 Watts essentially indefinitely, so fortunately I don’t weight 1,000 pounds.
The ultimate answer to all this stuff is I need to train more if I want to win races, but it’s nice to know that I have the capacity to do that. I can build my anaerobic capacity much more easily than increasing my aerobic capacity, and therefore need to wake myself up earlier and ride more.