On Saturday morning, I went back to the pain cave. Only this time, I wasn’t racing or doing an interval session in the woods. It was the return of the bane of my existence: a VO2 max / lactate threshold test on a treadmill.
Since I’m not an elite runner or skier, one might ask, why would I subject myself to this sort of pain? The last time I did this test was 11 years ago. As one ages, one’s maximum heart rate and VO2 max go down. In the fall of 2016, he heart rate zones I’d used for aerobic workouts for the previous 22 years stopped working. Nine months ago, I caved to the fact that my maximum heart rate isn’t 194 any more. I refigured my training zones with calculated guesswork based on training and race experiences. But I wanted to get an accurate assessment of where I should be training.
According to Sports Fitness Advisor, VO2 max is “the highest rate of oxygen consumption attainable during maximal or exhaustive exercise.” Another way to look at it is, VO2 max is a measure of your body’s ability to transport oxygen to your muscles. The more oxygen you deliver to your muscles, the harder / faster you can go. Norwegian cross-country skier Bjœrn Daehlie, who won multiple Olympic medals during his career, reportedly had a VO2 max of 96. Ultrarunner and skimo star Kilian Jornet’s VO2 max is 92. The bigger the number, the bigger your work capacity will be.
Lactic acid is a byproduct of exertion. According to exercise physiologist Dr. Harry Pino, who administered my test, “The harder you work, the more lactate your produce.” After a certain point, your body produces lactic acid faster than you can absorb it. That’s lactic threshold, and it accounts for the “burn” you feel after a hard effort. With smart training, you can improve your lactic threshold.
Arriving at Next Level Physical Therapy, I put on my running shoes and chatted with Dr. Pino about my goals. The start of the test was deceptive: just walking on a treadmill for a few minutes, Dr. Pino pricked my finger to get a blood sample, in order to measure baseline lactate.
After a warmup, Pino gradually increased the treadmill speed, periodically taking five additional blood samples to measure blood lactate. As you might expect, my heart rate gradually increased to keep up. After the final sample, it was time to dive into the pain cave. In addition to increasing the treadmill speed, he increased the incline.
“You can stop the test any time you want,” he said. “Just let me know.”
Three minutes went by, and I felt fine. Again, the speed and incline increased. Another three minutes, and again Dr. Pino ramped up the intensity. All the while he was calling out heart rate and lactate numbers, encouraging me to push harder. When the treadmill ratcheted to a nine per cent grade, I couldn’t go any harder.
The result? The bad but expected news: my VO2 max and maximum heart rate are lower than they used to be. While Dr Pino’s calculation of my level one training zone matched what I’d estimated, my lactic threshold is lower than I thought. The good news: Dr. Pino laid out an appropriate set of heart rate training zones where I can improve my lactic threshold. I’m looking forward to applying this data as thew new [training] year begins.