What Is a Good VO2 Max? Norms by Age, and How Lifters Raise It

TL;DR: For a man in his 30s, the median lab-measured VO2 max is about 40 ml/kg/min. In his 40s it's about 35 (Kaminsky et al., 2022). Women usually sit 15 to 20% lower at the same age. Anything above the median for your age and sex is good, and the top quartile is excellent. The biggest health payoff comes from getting out of the bottom 25%. Two short interval sessions a week, plus some easy aerobic work, will move it within eight weeks. Losing fat raises it too, because the number is divided by your body weight.

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VO2 max is one of the most important health numbers you've probably never been tested on. It measures the maximum amount of oxygen your body can use per minute, per kilogram of body weight. That makes it a combined score for your heart, lungs, blood, and the muscle that actually burns the oxygen. Your Apple Watch now estimates it in the background, which is why so many lifters are suddenly asking whether theirs is any good.

Here's how to read it, and what to do about it.

VO2 Max Norms by Age

The best US reference data comes from the FRIEND registry, which pools thousands of directly measured treadmill tests. These are lab numbers, not watch estimates. The 2022 update gives these medians (50th percentile) for men:

| Age | Median VO2 max, men (ml/kg/min) | |---|---| | 20-29 | 46.5 | | 30-39 | 39.7 | | 40-49 | 35.3 | | 50-59 | 29.2 | | 60-69 | 24.6 |

Source: Kaminsky et al., 2022.

Women's values follow the same curve but sit lower, mainly because of differences in hemoglobin, heart size, and body composition. In the earlier FRIEND standards, the median woman in her 20s tested at 37.6 ml/kg/min versus 48.0 for men, and in her 70s at 18.3 versus 24.4 (Kaminsky et al., 2015). A reasonable rule: take the men's median for your age and knock off 15 to 20%.

So what's "good"?

• Below the 25th percentile: low. This is the group with the highest risk, and the one with the most to gain.
• 25th to 50th: below average. Common in people who lift but never do cardio.
• 50th to 75th: good. You're fitter than most people your age.
• Above 75th: excellent. Usually means consistent aerobic training.

The number also falls with age, and the decline speeds up. It's modest in your 20s and 30s, then accelerates to more than 20% per decade after 70 (Fleg et al., 2005). Training doesn't stop the curve, but it shifts the whole thing upward, which means a fit 55-year-old can easily outscore a sedentary 35-year-old.

Why It Matters More Than Almost Any Other Metric

The mortality data on VO2 max is hard to ignore. In a study of 122,007 patients who did treadmill testing at the Cleveland Clinic, those in the lowest fitness group had about five times the risk of death of the elite group over the follow-up period, and the researchers found no upper limit to the benefit (Mandsager et al., 2018). A meta-analysis of 33 studies found that each 1-MET increase in fitness (3.5 ml/kg/min) was associated with a 13% lower risk of all-cause death (Kodama et al., 2009).

That's observational data, but the effect sizes are big enough that the American Heart Association has called for cardiorespiratory fitness to be treated as a clinical vital sign, alongside blood pressure and cholesterol (Ross et al., 2016). It sits in the same family as resting heart rate, just a far stronger signal.

The practical takeaway: 3.5 ml/kg/min is a realistic gain for most untrained people over a few months. That's not a marginal improvement. It's one full MET, and it's associated with a double-digit drop in risk.

Does Lifting Raise VO2 Max?

A bit, at first. In previously untrained people, resistance training produces small increases in VO2 max, mostly early on and mostly in those who started out least fit (Ozaki et al., 2013). Circuit-style training with short rests does more than heavy sets with long breaks.

But if your training is purely strength work, your VO2 max will plateau well below where it could be. That's why so many strong, lean lifters see a surprisingly mediocre Cardio Fitness score on their watch. The muscle is there. The aerobic engine hasn't been asked to do anything.

The good news is that there's a second lever lifters already pull. VO2 max is expressed per kilogram of body weight, so losing fat while keeping muscle raises it without any change in your heart. Drop from 95 to 88 kg at the same absolute oxygen uptake and your score climbs by about 8%. That's a real fitness gain in practical terms, since you're now moving less mass with the same engine.

How to Raise It Without Killing Your Gains

You don't need to become a runner. You need two things: some high-intensity intervals and a base of easy aerobic work.

1. Two interval sessions a week. The classic protocol is 4x4: four 4-minute efforts at 85 to 95% of max heart rate, with 3 minutes of easy movement between them. In one well-known trial, eight weeks of 4x4 intervals raised VO2 max by about 7%, while steady, moderate running at the same total work did almost nothing (Helgerud et al., 2007). A meta-analysis confirmed that both interval and continuous training work, with intervals producing slightly larger gains (Milanović et al., 2015). Use a bike, rower, or incline treadmill to keep the impact low.

2. Easy volume on other days. Two or three sessions of 30 to 45 minutes at a conversational pace. This is the zone 2 work that builds the aerobic base intervals sit on top of. Use the heart rate zone calculator to find your ranges instead of guessing.

3. Protect your lifting. Put intervals on upper-body days or on their own day, and keep them off the bike before heavy squats. The interference effect is real but small at this volume, and the order matters more than most people think. See whether to do cardio before or after lifting for how to sequence it.

4. Expect individual variation. The HERITAGE Family Study found that genetics explained close to half of how much people's VO2 max improved on the same training program (Bouchard et al., 1999). Some people jump 20%. Some barely move. Almost everyone improves something.

A Note on Your Watch's Number

Apple Watch's Cardio Fitness score is an estimate, not a lab test. Validation studies put the error at roughly 13 to 16% for an individual, with a tendency to underestimate fit people. Don't compare it directly to the table above with too much confidence. Compare it to itself. If you log the same kind of outdoor walk or run consistently, the trend over months is useful. The full breakdown is in how accurate Apple Watch VO2 max is.

The Bottom Line

A good VO2 max is anything above the median for your age and sex, and the top quartile is the goal worth chasing. If you lift but skip cardio, you're likely leaving a big chunk of your long-term health on the table. Two interval sessions and a couple of easy sessions a week will fix most of it within a couple of months, and getting leaner pushes the number up on its own.

The hard part is fitting that work in without your lifts paying for it. Protokl pulls your VO2 max, resting heart rate, and HRV from Apple Health and builds conditioning into your training week around your strength sessions, then tracks your body composition alongside it. You see whether your engine and your physique are both moving in the right direction, instead of guessing at one while the other slides.