REVIEW OF: Yu K et al, Am J Geriatr Psychiatry 2025;33(5):512–523

STUDY TYPE: Prospective cohort

We routinely encourage patients to exercise for mental health, but advice on how much to exercise is often vague. The World Health Organization (WHO) recommends 150–300 minutes per week of moderate to vigorous physical activity (MVPA), though much supporting evidence relies on self-report. This large UK Biobank study used accelerometers to objectively examine how activity and sedentary behavior relate to depression and anxiety risk.

Researchers followed 71,556 adults (mean age 62) without baseline depression or anxiety for a median of eight years. MVPA was grouped into four levels, and sedentary time was measured by daily inactive hours.

Meeting WHO guidelines was linked to a 29% lower risk of depression and a 20% lower risk of anxiety compared to < 75 minutes per week of activity. Depression risk plateaued at 150 minutes, while anxiety risk continued to improve beyond 300 minutes. The largest gains occurred when moving from very low activity to moderate levels, suggesting that some activity is much better than none. Total physical activity showed similar protective effects, while light physical activity had more modest associations, mainly for depression.

Higher sedentary time (> 10.6 hours per day) had a 19% higher risk of depression but not anxiety. Findings held up across age, sex, and BMI.

CARLAT TAKE
This study supports giving patients concrete, evidence-based targets: Aim for at least 150 minutes per week of MVPA (eg, brisk walking for 30 minutes most days). Start small, as just getting off the couch is where the biggest gains occur. Sedentary behavior matters too. Don’t just ask, “Do you exercise?” but “How much of your day is spent sitting?” Encourage patients to break up long periods of sitting, especially those starting from low activity levels.