When it comes to measuring fitness, many people focus on weight, body fat percentage or how fast they can run. But one of the most powerful indicators of overall cardiovascular health is something called VO₂ max.
VO₂ max stands for maximal oxygen consumption, the greatest amount of oxygen your body can use during intense exercise. Simply put, it measures how efficiently your heart, lungs, blood vessels and muscles work together to deliver and use oxygen. The higher your VO₂ max, the better your body is at producing energy during physical activity.
Think of VO₂ max as the size of your body’s “aerobic engine.” A larger engine allows you to exercise longer, recover more quickly, and perform everyday activities with less effort.
How Is VO₂ Max Different from Other Fitness Metrics?
Unlike heart rate, which tells you how fast your heart is beating, or heart rate variability (HRV), which reflects how well your nervous system is adapting to stress and recovery, VO₂ max measures your maximum aerobic capacity.
It isn’t just a performance metric for athletes. Research consistently shows that a higher VO₂ max is associated with a lower risk of heart disease, diabetes, cognitive decline and premature death. In fact, VO₂ max is widely considered one of the strongest predictors of long-term health and longevity.
How Is VO₂ Max Measured?
The gold standard is a specialty graded exercise test performed in a laboratory. During the test, you exercise on a treadmill or stationary bike while wearing a specialized mask that measures exactly how much oxygen you inhale and carbon dioxide you exhale as the intensity gradually increases. While this is amazing technology, it is clearly not readily available to the masses yet.
In the meanwhile, many wearable devices can also estimate VO₂ max based on your heart rate and exercise performance.
While wearable estimates aren’t as precise as laboratory testing, they are very useful for tracking changes over time when used consistently.
What’s a Good VO₂ Max?
VO₂ max is measured in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min). Much like HRV, normal values vary considerably based on age and sex, and they naturally decline with age.
Rather than comparing yourself to elite athletes, focus on improving your own number over time. For most healthy adults, maintaining an average or above-average VO₂ max for your age is associated with health benefits, while moving from a low fitness category to even an average one can significantly reduce future health risks.
How Can You Improve Your VO₂ Max?
The most effective way to increase VO₂ max is through regular aerobic exercise that challenges your cardiovascular system.
Strategies include:
While it is challenging to directly measure the specific impact of small gains in VO₂ max, other associated metrics can help us to understand the cardiovascular benefit. For instance, the ability to perform 1 additional MET on a treadmill test (equivalent to about 3.5mL/kg/min VO₂ max) is associated with a 13-14% lower all-cause mortality, and a 15-16% lower cardiovascular disease mortality rate. (source: https://pubmed.ncbi.nlm.nih.gov/39271056/)
The goal isn’t to achieve an elite athlete’s VO₂ max, it’s to improve your own. Small, consistent gains in aerobic fitness can translate into greater endurance, better energy, improved cardiovascular health and a longer, healthier life.
