Mixing Up Your Exercise May Reduce Risk of Death, Study Finds

Mixing up the types of exercise you do across the week may be worth prioritising: a new study reports a strong link between a greater variety of physical activities and a lower mortality risk.

Harvard T.H. Chan School of Public Health study links physical activity variety to mortality risk

Scientists at the Harvard T.H. Chan School of Public Health in the US examined data from more than 111,000 people collected over a 30-year period, comparing self-reported exercise routines with deaths recorded during the study.

After taking overall activity levels into account, the figures indicated that participants with the most varied exercise habits had a 19% lower risk of death over the study period than those whose exercise patterns were the least varied (assuming a broadly similar total amount of exercise).

“The findings support the notion that promoting engagement in a diverse range of physical activity types, alongside increasing total physical activity levels, may help reduce the risk of premature death,” the researchers write in their published paper.

To reduce the chances that the results were explained by other influences, the analysis adjusted for contributory factors such as lifestyle behaviours, demographic characteristics, and dietary patterns. Even so, because of the observational design, the research cannot prove direct cause and effect-rather, it highlights a robust association that warrants further investigation.

Why exercise variety might matter

The researchers note that rotating through different forms of exercise challenges different muscle groups and body systems, which could translate into broader, more balanced health gains than repeating the same activity alone.

The study also reinforced a familiar message: doing more exercise overall was associated with a longer lifespan, underlining the long-term value of building moderate physical activity into everyday life.

That relationship did not increase indefinitely, however. The researchers observed a plateau at around 20 hours per week (about 1,200 minutes): beyond this point, adding more hours did not substantially change mortality risk in either direction.

What counted as physical activity

The activities captured in the datasets spanned a wide range, including swimming, cycling, mowing the lawn, and climbing stairs. The key requirement was that the movement involved a reasonable level of effort-if it gets you moving with enough vigour, it counts.

“People naturally choose different activities over time based on their preferences and health conditions,” says nutrition scientist Yang Hu.

“When deciding how to exercise, keep in mind that there may be extra health benefits to engaging in multiple types of physical activity, rather than relying on a single type alone.”

Practical ways to add variety (without adding lots more time)

If you currently rely on one main activity, variety can be introduced by swapping in a different option once or twice a week-for example alternating cycling with swimming, adding a brisk walk on another day, or choosing stairs instead of lifts when practical. Many people find variety easier to sustain because it reduces boredom and can lessen repeated strain on the same joints and tissues.

It can also help to mix activities that develop different elements of fitness, such as aerobic exercise (for cardiovascular health), strength-focused work (to support muscles and bones), and balance or mobility sessions (which can be especially useful as we age). The goal is not perfection, but a broader spread of movement across the week.

Important limitations to keep in mind

Several constraints apply. Physical activity was self-reported rather than objectively measured, and the cohorts analysed were largely made up of White health professionals, which may limit how well the findings apply to other populations. In addition, the researchers did not test the impact of an individual changing their own routine over time; instead, they compared typical routines between different people.

Even with these caveats, the results offer a useful new perspective on exercise benefits. We already know that even small amounts of activity can be meaningful, and this study suggests it may be sensible to mix up exercise types as well.

Independent UK view and publication

“The new finding in this study was that physical activity variety may also be good for health,” says Tom Yates, a physiologist at the University of Leicester in the UK, who was not involved in the research.

“In some ways this might be analogous to diet, variety in and of itself could have health benefits.”

The research has been published in BMJ Medicine.