A VO2 max of 40 ml/kg/min is a solid fitness level for most adults, but exactly how good it is depends heavily on your age and sex. For a man in his 20s, 40 sits right around the 45th percentile, which is average. For a woman of the same age, 40 places her near the 85th percentile, which is excellent. And for a 50-year-old man, 40 would land well above the 95th percentile, putting him in superior territory.
The short answer: 40 ranges from average to exceptional depending on who you are. Here’s how to figure out where you actually stand.
How a VO2 Max of 40 Ranks by Age
VO2 max naturally declines with age, so the same number means very different things at 25 versus 55. For men, here’s roughly where a score of 40 falls:
- Ages 20 to 29: 45th percentile, labeled “fair” on standard fitness charts
- Ages 30 to 39: around the 90th percentile, considered excellent
- Ages 40 to 49: above the 95th percentile, superior
- Ages 50 and older: well above the 95th percentile, superior
For women, a VO2 max of 40 is impressive at almost any age. It exceeds the 85th percentile for women in their 20s and tops the chart entirely for women 30 and older. Men typically score 15 to 30 percent higher than women at the same age and training level, not because of effort or capability, but because of differences in lean muscle mass and oxygen-carrying capacity. Women naturally carry higher body fat percentages, and fat tissue doesn’t consume oxygen the way muscle does. So comparing your score against the right reference group matters.
What VO2 Max Actually Tells You
VO2 max measures the maximum amount of oxygen your body can use during intense exercise, expressed in milliliters of oxygen per kilogram of body weight per minute. It reflects how efficiently your heart pumps blood, your lungs exchange gases, and your muscles extract oxygen from that blood. A higher number means your cardiovascular system can deliver more fuel to working muscles before you hit your limit.
The American Heart Association has recommended that cardiorespiratory fitness be treated as a clinical vital sign, assessed alongside blood pressure, cholesterol, and blood sugar. That recommendation came because VO2 max is a stronger predictor of mortality and cardiovascular disease risk than traditional markers like obesity, diabetes, or high cholesterol. In practical terms, your VO2 max tells you more about your long-term health outlook than many of the numbers you get at an annual physical.
Good Versus Great Versus Elite
While a VO2 max of 40 to 45 ranks as “good” for the general population, competitive athletes operate at entirely different levels. Recreational runners who train consistently often land in the mid-40s to low 50s. Competitive endurance athletes typically range from 55 to 70, and elite cyclists or cross-country skiers can exceed 80.
That context helps calibrate expectations. If you’re a casual exerciser and you scored 40, you’re doing well. If you’re training seriously for endurance events, there’s meaningful room to improve. The good news is that VO2 max responds reliably to training. Most people can increase theirs by 10 to 20 percent with consistent aerobic exercise over several months.
How VO2 Max Connects to Longevity
Where your VO2 max sits relative to your age group has real implications for how long and how well you live. People in the bottom 25 percent for their age carry significantly higher cardiovascular risk, while those in the top quartile see substantial protection. Moving from a low category to even an average one produces some of the largest reductions in all-cause mortality available from any lifestyle change.
At 40 ml/kg/min, most adults are comfortably in the range associated with lower disease risk. For younger men, it signals adequate but improvable fitness. For middle-aged and older adults of either sex, it reflects a strong cardiovascular system that’s likely to serve them well.
How to Improve From 40
If you want to push your score higher, the most effective approach is high-intensity interval training. Alternating between near-maximal effort and recovery periods (think 4 minutes hard, 3 minutes easy, repeated 4 to 5 times) produces larger VO2 max gains than steady-state cardio alone. Two to three interval sessions per week, combined with longer moderate-effort workouts, is the formula most exercise physiologists recommend.
Consistency matters more than intensity on any single day. VO2 max improvements typically show up within 6 to 8 weeks of regular training, with the steepest gains happening in the first few months. People who start at a lower fitness level tend to see the biggest jumps, while those already at 40 or above may need to push harder or longer to move the needle. Losing excess body weight also helps, since VO2 max is calculated per kilogram. Dropping fat while maintaining muscle effectively raises your score even without changes in your heart’s raw output.
Sleep, recovery, and overall training volume also play a role. Overtraining can temporarily suppress your VO2 max, so building in rest days isn’t optional if you’re chasing a higher number.