Wednesday, March 14, 2012

VO2 Test to the "Max"

As a quick intro (as this post could get lengthy), a friend showed me a study that is going on at Northeastern University. In essence, it is comparing the response of males (age 18-35) who are healthy and Type I Diabetic in the presence or lack of a carbohydrate as fuel for exercise. The total test took 26 minutes at which point I completely blew up - my VO2 began to drop even though I continued to pedal. Once VO2 drops noticeably, the test is over because, well, you're not going to get a higher VO2 Max! It was done @ 60RPM steady (for ease of calculating power as a resultant, and for the specified repeatable protocol) with 5x2min at increasing resistance, then 3min intervals continually increasing until you bonk or VO2 values drop. This ergometer (AKA a work measuring exercise machine) used resistance units (in kp) as opposed to power (wattage), so VO2 Max power calculations are only estimates.

 Taking it easy. Not a comfortable bike fit by any means though!

"VO2 Max" is a term athletes of all types love to throw out there. You might hear someone say, "If only I could get my VO2 max to 70 or above, I'd be crushing the 5K in under 15 minutes!" Sure, VO2 Max determines the maximal uptake of oxygen of an individual during exercise and is thus a very good predictor of aerobic fitness. But what people really miss is that there are hundreds of other factors that actually play into being fast. The most important things in any sport are efficiency and economy, how much work you put in compared to what you get out. Example: A short paraphrase from Joe Friel's Blog on VO2 Max: Frank Shorter VO2 Max: 72, Bill Rodgers: 78. Who beat whom? Shorter won quite regularly. Basically having a high VO2 Max says that you have a good, solid engine. But if that engine is not well oiled, or the pistons aren't moving smoothly, or the explosions of the combustion are not well isolated then it won't go anywhere. The combination of having a big engine and an efficient engine is what makes and breaks world records. One or the other and you're an aerobic king whose running is a hobble, or you're a silky smooth athlete with perfect form and nothing to power it.

The test  itself was quite well run, as it should be for any scientific research. I had vitals taken while at rest prior to the test: Blood Pressure, Heart Rate, and Blood Glucose. John (name changed) briefed me on the procedure and what exactly I would be doing, all the overseers were very helpful - I brought my own pedals for the bike and they allowed me to adjust the seat to something moderately comfortable...I suppose I could have brought my backup saddle haha. They would monitor HR, BP, and all the VO2 values via the breathing mask. The mask was hot, dry, and a bit annoying considering that I usually intake a huge amount of water in training. So I warmed up a little bit cruising easy on the bike just to get the legs alive. I was not prepared for the 60RPM riding, also known as grinding it out, so I did a little of low rpm riding and was struggling to go below 70...this was going to be a blast!

The test started out easy on a 2/7 on their resistance scale, kp. Each level went up 0.5 kp. I indicated relative perceived exertion (RPE) at every stage and my BP was recorded by BP cuff in the middle of every stage, which ended up getting to be a pain one I hit a RPE of 15.

We started the ramp up and it was pretty darn easy, but it's supposed to be. I was aware how hard it would be getting in 15 minutes, but nevertheless was anxious for the 'real' part of the test. At this point my VO2 was in the 30's, as expected when the body is not being taxed - it doesn't need to utilize high oxygen uptake because the amount of oxygen being inhaled far exceeds the oxygen required by the cells, muscles, etc. Once that point is approached and turns is when the fun stuff happens. So we ramp up the resistance, and soon enough my RPE is 15 and we are into the 3 minute stages of the test. I'm still rolling along at a steady 60RPM, but am feeling the toll of the work I am putting in. The continual increase of effort with no rest is like running a race against Pre (if you haven't seen Without Limits...watch it) or climbing a hill at a constant speed but that darn hill's grade keeps increasing - and you're next to Jens Voigt, a man who doesn't know the phrase 'slow down'.

Stage 9, or 19 minutes into the test, things start hurting quite a bit. Any slight increase and my form will become rough and there is no smoothness in my pedal stroke. RPE is 18, heart rate (which was low for me on this day - not sure why) was into the 180's and climbing. John ramped up the resistance to 6.5 for stage 10, telling me that the ergometer could only go up to 7.0. If I continued through that stage, I would just increase RPM's until I bonked. I quickly learned that was not going to be necessary. John and his colleagues were pretty seriously cheering me on at this point, I later processed that it was humorous to think that these people in lab coats were pushing me to go harder. I wasn't sure if I would make it to 7.0 but I was destined to not let up until my body simply gave out. Midway through Stage 10 I saw the HR go into the 190's and my VO2 jump a little. I took this as motivation to hold out longer and push myself harder.

RPE = very high.

Stage 11: 7.0 kp. HOLY HELL. Well at least my BP is still stable...because nothing else was. The very moment they turned up the resistance I felt like molasses. After 5-10 seconds I made the adjustments and was up to 62rpm from getting pushed down to 57. If I didn't get above 60rpm the test would be over, as I would essentially have bonked and thus my body gave out and my Max VO2 value would not get any higher. Everything is completely burning at this point and I feel like I can't breathe - note: this feeling is normal when maxing oneself out, but when you have a mask on you just want to rip the damn thing off!


1 minute at 7.0kp and everything is empty, I am still pedaling above 60rpm but it must be a hideous sight: bouncy, strained, lacking any resemblance to smoothness. I overhear that my VO2 value is not increasing anymore...I look up and it has gone down since 30 seconds prior. I muster up enough strength to press on, but John says that the test is over because my VO2 is starting to decrease and, to my understanding, I have aerobically bonked and my legs are very quickly packing themselves full of lactate.

It hurt. But it was a great workout! Plus, I got all the data of my VO2 Max test, so it's pretty cool stuff. Luckily I have the knowledge to be aware that VO2 values are not the bottom line...so whether it was high or low from what I was expecting, it wasn't going to change a darn thing. Luckily it turned out well and put me right in a range I was thinking I would be.

All in all, I'm looking forward to heading back down to Northeastern for the last two tests - anaerobic wingate, yeehaw!

No comments:

Post a Comment