Exercise tied to better mental health, but more is not necessarily better

Adults who exercise have better mental health than those who do not, according to a cross-sectional study in the Lancet Psychiatry.

Researchers examined data on 1.2 million adults who completed the CDC's Behavioural Risk Factor Surveillance System survey between 2011 and 2015. Overall, participants reported that they had experienced an average of 3.4 days in the past month on which their mental health was "not good."

Those who reported exercising in the past month had about 1.5 fewer poor-mental-health days than those who did not exercise. All types of exercise were associated with better mental health, but popular sports (mostly team sports), cycling, and aerobic/gym exercises conferred the greatest benefit.

Of note, exercising for 45 minutes per session, three to five times per week, was associated with the best mental health. Longer durations (e.g., 90 minutes per session) and greater frequencies (>5 times a week) were linked to worse mental health.