150 minutes a week or less: what kind of exercise is associated with better survival after cancer

Moderate physical activity has long been considered good for the heart and overall health. Now scientists have mounting evidence that movement may also be linked to survival rates in people already facing cancer.

In a new study published in JAMA Network Open, the authors report: higher levels of physical activity after a cancer diagnosis correlate with a lower risk of dying from the disease - including in patients with bladder, endometrial, lung and ovarian cancer.

What exactly was studied

An international team of researchers pooled data from six large long-term cohort studies. The final sample included 17,141 survivors of one of seven types of cancer: bladder, endometrial, kidney, lung, oral, ovarian and rectal.

Participants reported their physical activity in their free time:

• before diagnosis,
• and about 2.8 years afterwards.

Researchers then followed them for an average of about 11 years, assessing how changes in activity correlated with risk of death. To separate the contribution of movement from other factors, the analyses were adjusted for important variables - such as age, gender, smoking and disease stage.

Main findings

The authors report a pronounced association between physical activity and lower mortality in a number of localisations. Translations of the results often cite these estimates of reduced risk of death:

• for oral cancer, up to 61%,
• for lung cancer, about 44%,
• for endometrial cancer, about 38%,
• for bladder cancer, about 33%.

Separately, a practical conclusion is emphasised: it is "not too late" to start moving. People who were sedentary before diagnosis, but then started exercising regularly, also showed a marked reduction in their risk of death - particularly for lung and colon cancer.

Another important detail: the benefits were not only seen in those who met the "classic" recommendations (like 150 minutes of activity per week). For some cancers, even exertion below that level looked better than no movement at all.

"More is not always better, but sometimes it helps."

The researchers also describe a dose-dependent relationship: for certain diagnoses, more activity (above standard recommendations) was associated with additional risk reduction. However, the key message remains simple: any increase in movement can make a difference, especially if there was little activity initially.

Why this matters to clinicians and patients

An accompanying invited commentary, also published in JAMA Network Open, emphasises the need to more aggressively promote physical activity "across the spectrum of cancer" - but taking into account individual limitations, symptoms, stage of treatment and differences between patient groups.

However, it is important to remember: this is observational data (albeit very large) and physical activity was assessed by self-report, so these results describe an association rather than prove a causal effect. In practice, it is safest to discuss an exercise plan with the treatment team - especially if there are complications of therapy, severe weakness, anaemia, pain or respiratory problems.