V02 max—the measure of how efficiently your body utilizes oxygen during exercise—is widely considered to be the definitive indicator of cardiovascular fitness. However, this powerful metric remains largely the domain of die-hard exercise enthusiasts and elite-level athletes, not least because of the time-consuming and expensive (not to mention, brutally exhausting) in-lab testing typically required to measure it accurately. And that’s to say nothing of what it actually takes to increase your V02 max, which tends to involve gut-busting interval workouts designed to gradually stretch your body’s appetite for oxygen. But improving your V02 max can unlock a trove of worthwhile real-world benefits that hold currency far beyond helping you hit a quicker track time, train for a half-marathon, or complete your first Hyrox competition. And while medical-grade testing is still the most accurate way to measure it, many of the best fitness trackers can now do a decent enough job of estimating your V02 max using heart-rate data, putting the benefits within arm’s reach of the average person. Here, experts from the front lines of performance coaching and exercise science make the case for why you might want to consider making an effort to increase your V02 max—unpacking some of the most noteworthy and useful real-world applications. Increasing your V02 max is a surefire way to up your game, whether you’re a runner, cyclist or pretty much any kind of athlete. But even if you are decidedly none of those things, it can be a powerful means to improving both your longevity and overall quality of life. "It definitely slashes your risk of premature death,” says Kristen Holmes, global head of human performance and principal scientist at the health and fitness wearable company Whoop, who points to compounding research, including, most recently, a 2024 review published in the British Journal of Sports Medicine. “They were able to show this really big decrease in risk of premature death—by 11 to 17 percent—by just boosting your VO2 max.” And in the meantime, a better V02 max can just make life, well, easier. “Imagine you're wildly unfit, you've never exercised, and you encounter a set of stairs,” says Danny King, director of performance and recovery at athletic club Life Time. “Going up that set of stairs is likely pushing you to 85 percent of your VO2 max. You'll be working relatively hard.” Now imagine you have a higher V02 max. “Going up that set of stairs, you’re at 15–20 percent. It's easy for you,” King says. “[In the first scenario], everything you do in life is done at a higher percentage. But the higher you push your V02 max, the easier basically everything else you do in life is going to be. When you mow your lawn, when you play with your kids, when you go do all these things, if you have a larger tank and a larger capacity, everything is done at a lower percentage, thus making it that much easier for you.” While typically pigeon-holed as a physical fitness metric, V02 max could also play an important and holistic role in overall mental health, says IM8 ambassador and performance coach to 2025 US Open winner Aryna Sabalenka Jason Stacy.. “Most people are sitting in a sympathetic state a lot of the time, in this low-level stress, and that wears you out,” Stacy says “It can impact your ability to perform at your job, and it can impact your relationships with your family, friends, and loved ones.” “[When you improve your V02 max], there's less stress on your overall system. And when there's less stress on your overall system, it's much easier for you to manage your emotions. It's much easier for you to step back and make better decisions and see things for how they are, rather than being caught up in all the day-to-day stresses.” A 2025 study published in the Journal of Medical Internet Research similarly observed a strong link between cardiovascular fitness and self-reported mental health markers like anxiety, depression, and stress. "Things like anxiety and depression are highly correlated with fitness levels,” says Holmes, who served as a co-author on the study. “People who are less fit have higher perceived stress, and score less well on measures of depression. So we know there's definitely a relationship between your fitness levels and your mental health." Overall, when you increase your V02 max, you’re freeing up your body’s physical and mental resources, Stacy says. “Not only are you going to feel better, be able to think more clearly, and be able to manage all the noise around you better, but you know what? You're going to improve your relationships. And you're going to be able to have more energy to give to those whom you want to give to—not just the people and things you have to give to.”