Traditional exercise advice often focuses on doing more. However, new research suggests that this approach overlooks an important factor.
A large, long-term study that followed over 100,000 people for more than 30 years found that the variety of physical activity a person engages in may be just as important as the total amount. In some cases, this variety may matter even more.
Researchers at Harvard T.H. Chan School of Public Health led the study, which was published in BMJ Medicine. They used data from two major cohort studies, the Nurses’ Health Study and the Health Professionals Follow-Up Study, to examine how different types and combinations of exercise relate to mortality risk over time.
The new findings add important new insights that, in contrast with traditional views, primarily focus on the amount of exercise performed.
Three Decades of Data
The analysis included over 111,000 participants who reported their exercise habits every two years for more than 30 years. The researchers assessed both the total amount of physical activity and the variety of activities, which ranged from walking and running to resistance training, yoga, gardening, and stair climbing.
The researchers used metabolic equivalent of task (MET) scores to measure activity levels. Researchers calculate this standard measure of energy expenditure by multiplying the time spent on each activity by its metabolic equivalent value. During the follow-up period, 38,847 participants died. Of these, 9,901 deaths were from cardiovascular disease, 10,719 from cancer, and 3,159 from respiratory disease.
More Isn’t Always Better
People who were more active overall had a lower mortality risk, but the benefit did not extend beyond this. The advantage leveled off at about 20 weekly MET hours, suggesting that exceeding this level yielded only small additional gains.
Walking showed the strongest association. The most active walkers had a 17% lower mortality risk than the least active. Stair climbing was linked to a 10% reduction. Tennis, squash, or racquetball were associated with a 15% lower risk, while rowing or calisthenics were linked to a 14% reduction. Running and resistance training each accounted for a 13% reduction in mortality risk, while jogging and cycling accounted for reductions of 11% and 4%, respectively. Swimming was the exception, with no statistically significant association with reduced mortality.
The Advantage of Variety
The data also showed that exercise variety provided its own benefit, separate from total activity. After accounting for total exercise levels, participants who engaged in the widest range of activities had a 19% lower risk of death from all causes than those with the least variety of activities.
This benefit from exercise variety extended across specific causes of death. The group with the most diverse activity patterns showed a 13 to 41% lower risk of death from cardiovascular disease, cancer, respiratory disease, and other causes.
The association between exercise variety and lower mortality persisted even when researchers controlled for the amount of total exercise participants were doing. In other words, two people who logged the same amount of exercise did not have the same risk. Those who spread that activity across more types of movement consistently showed better outcomes.
Limitations of the Findings
Since the study was observational, associations can be identified but cannot be used to establish a direct cause-and-effect relationship. Participants also self-reported their own activity levels, which could lead to inaccurate results. Additionally, the MET scores assumed that all participants were fully engaged in each activity, and not knowing the intensity could have led to some mistakes. Also, since most participants were white, the results might not apply to everyone.
The researchers conclude that long-term engagement in multiple types of physical activity may help extend lifespan. This benefit appears to exist independently of the total amount of exercise a person does. Staying active is important; however, the ways you stay active and the variety of movements you use may matter more than the total time spent exercising.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.