A new analysis suggests that varying exercise routines, such as mixing running, cycling, and swimming, may reduce mortality risk by 19 percent compared to less diverse workouts, even when total activity levels are similar. Researchers examined data from over 110,000 U.S. participants tracked for more than three decades. The findings highlight potential benefits of exercise variety, though they remain suggestive rather than conclusive.
Researchers have uncovered evidence that incorporating a mix of physical activities could contribute to a longer lifespan. An analysis of two major U.S. studies, spanning from 1986 to 2018, involved 70,000 women from the Nurses’ Health Study and 41,000 men from the Health Professionals Follow-Up Study. Participants reported their activities via questionnaires every two years, excluding those with conditions limiting exercise.
The study focused on nine primarily aerobic activities: walking; jogging at paces slower than 6.2 minutes per kilometer; running; cycling outdoors or on stationary bikes; stair climbing; lap swimming; rowing or calisthenics like squats and pull-ups; tennis, squash, or racquetball; and weight or resistance training. Those engaging in a variety of these exercises showed a 19 percent lower risk of death from any cause over the 30-plus-year period, compared to equally active individuals with narrower routines.
"If the total amount of physical activity is kept constant, you will get additional benefits from doing a mix of physical activities," explained Han Han at Harvard University. However, such observational studies cannot prove causation, and self-reported data may overestimate activity levels while healthier people tend to exercise more, potentially biasing results.
Benefits may plateau after a few hours weekly per activity type, suggesting variety helps by introducing new physiological effects or avoiding overuse. "We think that future studies could examine the possible synergistic effects of different activities," Han noted, adding that optimal mixes might evolve with age.
Duck-chul Lee at the University of Pittsburgh urged caution in interpretation but pointed to support from World Health Organization guidelines, which recommend combining aerobic and resistance exercises for broader health gains. Future research could leverage wearable trackers for more precise data, though long-term tracking currently relies on surveys.
The findings appear in BMJ Medicine (DOI: 10.1136/bmjmed-2025-001513).
