It’s no secret that working out is good for your health, but now, a new study is showing how it can save your life. Researchers from the University of South Australia have found that cardiorespiratory fitness (CRF) can lower the risk of premature death, chronic diseases, and complications from poor health by a staggering 20 percent.
Cardiorespiratory fitness is a measure of how well your heart, lungs, and muscles work together to supply oxygen to your body during sustained physical activity. It’s often measured by VO2 max — the maximum amount of oxygen your body can use during intense exercise. The higher your cardiorespiratory fitness level, the more efficiently your body can transport and use oxygen.
Publishing their work in the British Journal of Sports Medicine, the international research team analyzed data from a staggering 199 studies, including over 20 million participants. They looked at how cardiorespiratory fitness levels predicted future health outcomes.
The results were striking. People with high fitness levels had a 41 to 53-percent lower risk of premature death from any cause compared to those with low fitness. Each incremental increase in fitness of 1 MET (a measure of exercise intensity) was associated with a seven to 51-percent lower mortality risk, depending on the cause of death. The protective effects were applicable to deaths from cardiovascular disease, cancer, and sudden cardiac events.
“The message is quite simple: if you do a lot of ‘huff and puff’ exercise, then your risk of dying early or developing diseases in the future is reduced. If you avoid exercise your health may suffer,” says senior study author Grant Tomkinson, a professor at the University of South Australia, in a media release.
The benefits went far beyond longevity
High fitness was also linked to a 37 to 69-percent reduced risk of developing chronic conditions like hypertension, heart failure, stroke, atrial fibrillation, dementia, and depression. Even in people already diagnosed with heart disease, cancer, and other chronic illnesses, those who were more fit had a significantly lower risk of dying.
While we’ve long known that being active is good for health, this study provides a more precise understanding of the dose-response relationship between fitness and specific outcomes. It suggests that any improvement in fitness — even modest changes — can provide substantial health benefits, especially for those starting at a low baseline.
Importantly, cardiorespiratory fitness isn’t just about how much you can exercise — it’s influenced by a combination of physical activity, genetics, and other factors like age and health status. This means that while some people may need to work harder to improve their fitness, almost everyone can boost their cardiorespiratory health through regular aerobic exercise like brisk walking, cycling, swimming, or dancing.
“People can make meaningful improvements through additional moderate physical activity, such as brisk walking, at least 150 minutes a week. And as they improve their fitness, their risk of death and disease will decline,” explains lead study author Dr. Justin Lang, from the Public Health Agency of Canada and adjunct professor at the University of South Australia.
Researchers noted some limitations in the current evidence that point to areas for future research. Most studies to date have involved male-dominated groups, highlighting a need for more data on women’s fitness. There was also a lack of high-quality studies in some patient populations and research on links between fitness and specific cancers and mental health outcomes beyond depression.
Overall, the breadth and consistency of the protective associations across diverse health outcomes make a compelling case for the importance of cardiorespiratory fitness as a key vital sign. The authors argue it should be routinely measured in healthcare settings to help identify individuals at elevated risk who could benefit from interventions.
“Through regular assessment, clinicians and exercise professionals could better identify adults at greater risk of early death and initiate exercise programs aimed at increasing CRF through regular physical activity,” concludes Dr. Lang.
On a population level, the findings underscore the critical importance of promoting physical activity and providing infrastructure that supports active lifestyles. In an age when sedentary behaviors are a constant part of life, making movement a regular part of our days should be a top public health priority.
