Mind & Body

Why You Need a Healthy VO2max (and How You Can Get It)

In the fitness world, there are generally two camps: the cardio buffs and the strength devotees. Some swear by a run or a ride to get their heart pumping; others break a sweat by pumping iron at the gym. It turns out that if you're exercising for the health benefits — and in the long run, you should be — cardio fitness is important for everyone, runners and lifters alike. Research shows that having a high VO2max, scientists' best measure of cardio fitness, comes with a host of health benefits.

Related Video: 3 Simple Cardio Exercises You Can Do Anywhere

My Air Bag Brings All the Boys to My Yard

What's now known as VO2max was first explored by exercise physiologist A.V. Hill in the 1920s, who called it "maximal oxygen intake" at the time. By then, he had already won a joint Nobel Prize with Otto Meyerhof for discovering the difference between aerobic and anaerobic metabolism within muscles. The way Hill examined maximal oxygen intake was delightfully quaint by today's standards. For one thing, he performed the studies on himself and his friends. As Alex Hutchinson writes in his book Endure, "The experiments on Hill and his colleagues involved running in tight circles around an 85-meter grass loop in Hill's garden (a standard track, by comparison, is 400 meters long) with an air bag strapped to their backs connected to a breathing apparatus to measure their oxygen consumption."

Predictably, the faster they ran, the more oxygen they consumed. But Hill noticed that there was a cutoff point. Once their cardiorespiratory systems hit this invisible line, they could keep running faster, but their oxygen consumption didn't keep up. That invisible line was what Hill called the maximal oxygen intake: what we know of today as VO2max. (VO2max is an acronym in which V stands for "volume," "O2" stands for "oxygen," and "max" stands for "maximum.")

This number is the point at which your muscles can't take in any more oxygen. Your muscles need oxygen because it's what helps them turn glucose, or sugar, into the fuel known as ATP, which in turn keeps them working hard. Like Hill discovered, the harder you exercise, the more oxygen you need to produce even more fuel.

But the opposite is also true: the more oxygen your muscles can use, the harder you can exercise. Studies over the decades have found that VO2max is the one of, if not the, most important elements when it comes to performance in endurance sports. Some of the most celebrated cyclists and runners also have the highest VO2max values: Lance Armstrong's is 85 ml/kg; Usain Bolt's is 88.2 ml/kg. Meanwhile, experts rate anything beyond 50 ml/kg for a man as "superior."

But most of us aren't cycling the Tour de France or trying to break the 100-meter world record. We're just trying to live long, healthy lives — while perhaps avoiding so much huffing and puffing when we take the stairs. Does VO2max really matter for the average joe?

VO2 the Max

The answer is a resounding yes. VO2max is a measure of cardio fitness, and good cardio fitness is associated with a decrease in a person's risk of death, both from specific diseases and from general causes. And in November, researchers made a direct link between VO2max and heart health by measuring the VO2max of more than 4,500 healthy men and women, then following them for nearly a decade. They found that the better a participant's VO2max, the lower their risk for cardiovascular disease. Those with the highest VO2max had nearly half the risk of those with the lowest.

So how do you know if you have a good VO2max? Unfortunately, it's not easy; you usually have to go to a lab, strap on a face mask and heart-rate monitor, and run on a treadmill as fast as you can for as long as possible. Luckily, there are other indicators you can use. Many smartwatches can make rough estimates of VO2max, and barring that, studies show that your resting heart rate is a pretty good predictor as well.

While it depends on your age, very broadly speaking, a healthy VO2max is somewhere between 35 and 50 ml/kg for men and 27 and 42 ml/kg for women. (Check out this chart to get a little more detail.) If you find that yours lags behind a bit, don't fret. You can improve your number with more cardiovascular exercise. You know you're exercising at the right intensity for boosting your VO2max by using the "talk test": If you're working just hard enough that conversation starts to be difficult, you're doing it right.

So what are you waiting for? Get out there and sweat. At least you don't have to run in circles wearing an oxygen bag while you do it.

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Discover just how far the human body can go (and why it may not have gone there yet) in the book "Endure" by Alex Hutchinson. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Ashley Hamer January 31, 2019

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