VO2 Max and Longevity: Why Fitness Is One of the Best Predictors of Healthy Ageing

Updated September 2026

VO2 max is the maximum amount of oxygen your body can take in and use during hard exercise. It reflects how well your heart, lungs, blood vessels and muscles work together, and it's one of the most useful markers of cardiorespiratory fitness. It's measured in millilitres of oxygen per kilogram of body weight per minute (mL/kg/min).

Why VO2 max matters for longevity

Large studies consistently link higher cardiorespiratory fitness with longer life:

• A 2018 study of more than 122,000 adults who completed treadmill testing found that lower fitness was associated with a markedly higher risk of death over the follow up period, and people with the highest fitness had the lowest risk.¹
• A meta analysis in JAMA found that each 1 MET increase in fitness (a standard unit of exercise capacity) was associated with around a 13% lower risk of death from any cause.²

These are observational studies, so fitter people may differ in other ways too. But the pattern is strong and consistent, and fitness is something you can change.

How VO2 max changes with age

VO2 max naturally declines as we get older, and inactivity speeds that decline. The encouraging part is that it responds to training at any age, and even modest improvements from a low starting point are associated with meaningful benefits.

How to improve your VO2 max

1. Build a base with regular moderate activity. Brisk walking, cycling, swimming or jogging at a pace where you can talk but not sing. Australia's Physical Activity Guidelines recommend 150 to 300 minutes of moderate activity, or 75 to 150 minutes of vigorous activity, each week, plus muscle strengthening activities on at least two days.³

2. Add some higher intensity intervals. Intervals are one of the most effective ways to improve VO2 max. A widely studied format is four intervals of four minutes at a hard effort (you can only say a few words), each followed by three minutes of easy recovery. Once or twice a week is plenty for most people.

3. Progress gradually. Increase duration or intensity a little at a time, and build in easy days to recover.

4. Choose activities you enjoy. Running, cycling, rowing, swimming, hiking and dance classes all count. Consistency matters far more than the perfect program.

If you have a heart condition, other health concerns or haven't exercised for a while, check with your GP before starting higher intensity training.

How to track your progress

Lab testing is the most accurate way to measure VO2 max, but many smartwatches give an estimate that's useful for tracking trends over time. Real world signs of improvement include finding stairs and hills easier, recovering faster after effort and a gradually lower resting heart rate.

The bottom line

Cardiorespiratory fitness is one of the strongest predictors of long term health, and it's never too late to improve it. Build a base of regular moderate activity, add some intervals, include strength training and stay consistent.

Where Keeper fits: Training comes first. For a daily supplement that fits alongside an active routine, Keeper Complete Longevity includes CoQ10, magnesium and NAD+ precursors in one serve, and Keeper Body Boost includes creatine, collagen and HMB. Every batch is third party tested.

References

1. Mandsager K et al. Association of cardiorespiratory fitness with long term mortality among adults undergoing exercise treadmill testing. JAMA Netw Open. 2018.
2. Kodama S et al. Cardiorespiratory fitness as a quantitative predictor of all cause mortality and cardiovascular events. JAMA. 2009.
3. Australian Government Department of Health. Physical activity and exercise guidelines for all Australians.

This article is general information only and isn't a substitute for advice from your healthcare professional.