Why? It represents an individual’s maximum capacity for processing oxygen during exercise—loosely analogous to a top horsepower rating for a car.
If your motor produces 350 horses and your rival’s only has a 300 horsepower rating you’re going to blow her doors off, right? The answer is a definite “maybe.” But before examining how VO2 max affects performance, you need to understand how it’s measured and what it represents.
Measuring VO2 Max
The only way to get a true VO2 max reading is to perform a carefully calibrated test in an exercise laboratory. There are loads of VO2 max “calculators” that attempt to predict your score based on a race time or a workout, but those are best-guess VO2 max tests; they’re not the same thing as an actual lab measurement.
The scientifically measured lab version fits an athlete with a mask covering both nose and mouth in order to monitor the amount of oxygen and carbon dioxide that is inhaled and exhaled during a progressively more challenging effort. The maximum score is noted when the oxygen uptake remains constant even though the workload keeps increasing. That redline level signals the end of the test—and often the imminent collapse of the runner onto the lab floor.
The test results are measured in either liters per minute or liters per kilogram of bodyweight. The former represents an absolute measure of aerobic power, while the latter balances that oxygen-processing ability against the athlete’s weight. One of the quickest ways to boost a VO2 max score is to lose a few pounds. However, losing weight can hurt a real-world performance just as quickly. If your VO2 max score goes from 64 to 65, for example, but you soon catch a cold because you crash dieted, or don’t have enough energy to power your run, the real-world results are going to bum you out.
How To Improve Your VO2 Max
For all but the best conditioned athletes who are already at the top of their max, a well-considered schedule of running workouts will reliably lead to improvements. Forget the outdated notion that VO2 max is “genetically determined” and can’t be improved, though some athletes are predisposed to high VO2 max capabilities. All phases of training, from low-intensity base-building sessions to high-intensity intervals, have a positive effect.
Because the test itself is so grueling and seems to hinge on the final few agonizing minutes, many runners think of their hardest workouts as VO2 max-boosters. In truth, upping your max number requires a broad mix of training efforts. It’s true that short, hard intervals often provide the best stimulation when measured over a very short timeframe, but running nothing but max-effort intervals is unlikely to be a successful strategy for the long haul.