Wednesday, April 30, 2008

VO2 Max Test

video
So I got to do a VO2 max test on the treadmill this morning. Up above is a little video shot with my cellphone by our exercise physiologist... it's only a few seconds long and a bit blurry on the blogger video thing, but it hopefully can help illustrate what's going on.

The weird thing I'm wearing is headgear with an attached mouthpiece and two-way valve, so my inspired air comes from the room, but my expired air goes to a device for measuring respiration as well as gas analyzers. I'm also hooked up to a 12 lead ECG so that they can make sure I'm not going to keel over an die for one, but also so that I can know my max heart rate.

The basic idea is to go from a moderate work load (I started at about 5.5 mph and no grade, which is something I feel very comfortable with on a treadmill) and keep moving up the grade and speed (mostly grade goes up to keep people from falling off the treadmill) while watching the person's oxygen consumption... when the workload increases but oxygen consumption does not, then you've reached your VO2 max.

If I didn't already know that I have really gotten past being "just" overweight onto the threshold of obesity, then looking at the numbers of this test make that a obvious certainty. My untrained, and very out of shape, VO2 was actually a very respectable 4.2 liters per minute... but because a seven foot man is going to consume more oxygen than a four and a half foot woman, even if that woman is a marathon runner, VO2 is pretty much always reported normalized by weight. Then, because I'm about 6' and 221 lbs right now, and thus at least 20-40 lbs overweight (according to BMI anyway)... my VO2 is 42 milliliters per kilogram per minute, which is on the low end of normal for my age, but if I can drop 10 kilograms (i.e. 22 lbs which is my goal right now) that equates to a %10 increase without even accounting for training effect. So that's a little extra motivation to get me to the next test I hope to take in 6 months after some good training and (hopefully) serious weight loss.

I haven't been planning on changing my diet for calorie reduction purposes(I do mean to eat better though), but this is pushing me towards that a bit. The most obvious thing to do is to cut down on the Belgian beers, but I do love me some Tripel, so that is not a path I will embark on lightly... I think I still plan to see where I am in 6 months and then think how radically I need to alter my diet.

Another note... my max heart rate is actually 171 bpm, and not my age predicted maximum of 189... so that means I've been working much harder than I had been thinking... so that's kind of encouraging, actually.