|Ultrasound looking at muscle glycogen stores.|
All photos: Charlotte Freer
|The dreadmill, with all kinds of fancy equipment.|
I began by walking on the treadmill at 3mph (20:00/mile), which increased by 1 mph each minute, until reaching 6mph (10:00/mile) at the four-minute mark. From that point on, with each passing minute, the incline increased by 2%. Beth informed me that the treadmill had a max gradient of 20%, after which (if I was still running) the speed would then increase to 7mph (8:30 pace) for a minute. If I could somehow keep going for that minute, the test would automatically stop. And so I arrived at my arbitrary goal.
If you've never had a VO2max test before, it is a very brief, very exquisite sort of torture. The goal is to push the athlete to run to their maximum effort; thus, the test needs to be difficult enough to induce exhaustion, but short enough that the athlete doesn't end the test prior to reaching their max due to accumulated fatigue. For the first eight minutes or so, then, the test is rather benign, but as the grade pushes past 12%, it begins to get unpleasant quite rapidly. After eleven minutes, I reached 16% and was really starting to feel it. At twelve minutes and 18%, I knew I could at least get to the 20% maximum grade, but I wasn't sure how long I could hold it there. I fought my way through the entire minute at 20% and briefly entertained the possibility that I could finish an entire minute at 20% and 7mph, but after about 15 seconds I gave a desperate signal to stop.
The numbers were pretty cool; it's amazing how much data is generated from these tests and what it can be used for. I was able to reach a VO2max of 4.59 L/min, or 70.1 ml/kg/min, which is a pretty solid value for an old man. My ventilatory/lactate threshold occurred at 88% of my VO2max, which is near the upper end of normal. (Higher is better: beyond the LT, lactate accumulation occurs faster than lactate clearance, and the steady accumulation of lactate will lead to fatigue; thus, being able to exercise as close to max effort as possible before reaching that point is obviously beneficial.) Most interesting to me were the RER values. I didn't start burning carbs at all until I was nearly halfway through the test, and I didn't hit an RER of 0.85 (metabolizing 50% carbs and 50% fat) until the ten-minute mark, running at at 14% grade with a heart rate of 171. (My max HR came in at 184, slightly above predicted.) Beth described this as very unusual, but consistent with the theory behind the ketogenic diet. Nice to see that it's working.
|Torture device. I mean, the Biodex.|
|Probably before I knew what was coming.|
|Waiting with dread...|
|Either really tired, or just anticipating getting back on the Biodex.|