VO2 Max…it sounds like some kind of potentially illegal performance-enhancement supplement you can only get in Canada! Actually, the letters mean V for volume, O2 for oxygen, and “max” for maximum. In simple terms, it’s a measure of the maximum amount (volume) of oxygen the body can effectively put to use during exercise. Why do we care? VO2 Max matters for different reasons, based on your fitness goals: reducing overall body fat, improving performance, and enhancing overall health.
What is VO2 max?
The greater the effort you expend during exercise, the more oxygen you consume to produce energy. However, there’s a maximum point for each person, beyond which increases in exercise intensity don’t lead to further increases in oxygen consumption. This “cut-off point” is a person’s VO2 max.
Why Measure VO2 max?
So why should we measure VO2 max? For a hardcore cyclist, runner or endurance athlete, trash talk material might be one reason. Seriously though, as I consider myself a bit of a hardcore triathlete, and having had my VO2 max measured in a laboratory setting three times, I recognize how this number can become a benchmark for measuring success as an athlete – but it need not be. While there are differing opinions in the sports science community about the role of VO2 max and performance, the view that makes the most sense to me is that performance is the result a combination of many factors, such as muscle adaptation, efficiency, metabolism, and red blood cell count.
Interestingly, genetics also plays a major role in each person’s VO2 max, and may account for as much as a 25% to 50% of the variance between individuals. External factors such as altitude also affect VO2 max – it starts to decrease at an altitude of 5,249 feet (the altitude of Denver Colorado). For every 3,281 feet above that, maximum oxygen uptake decreases by 8 to 11%.
Nevertheless, for most of us ordinary mortals, developing a higher VO2 max does play a part in improved performance. Let’s look at this in the context of running. Establishing a baseline measurement followed by periodic re-testing will help to gauge the effectiveness of a training program designed to enhance performance at a given race distance. Not surprisingly, VO2 max increases have a greater impact on performance at the shorter, higher-intensity race distances of the mile and 5k.
An even more important measure for runners is velocity at VO2 max (vVO2 max), or how fast a person was actually running when they reached their VO2 max. Knowing and then training at this pace in short, high-intensity intervals (what runners call “speed work”) will help to increase VO2 max over time.
High-intensity interval training provides an optimal stimulus for improving VO2 max. Longer intervals of three to five minutes are the most effective, because VO2 max is reached and sustained during these intervals. As well, shorter intervals of under one minute can also improve VO2 max when combined with correspondingly short, active recovery periods to keep VO2 elevated throughout the workout. During the first interval, VO2 rises rapidly and begins to plateau toward the end of the interval. During the recovery period, VO2 decreases – but if the recovery period is short (i.e. less than or equal to the work period), it won’t decrease all the way back to resting value. The next interval then begins with VO2 at an elevated level. A weekly exercise program that combines high-intensity intervals with appropriate recovery and cross training should produce an improvement in VO2 max over a three to four week period. After that, an even higher level of intensity (stimulus) is needed to produce greater gains.
“Working hard and putting in the effort is a critical component to succeeding, but understanding the thought process and theory behind your training is also important. Knowing why you’re performing a certain workout or training a specific way can make reaching your goals easier, and provide that extra 10% needed to succeed on race day.” Jeff Gaudette