For depression, hard aerobic sessions beat intervals

Exercise is regularly recommended for depression, but most of that evidence concerns moderate activity, and it has been less clear whether training hard offers anything for people already living with the condition. High-intensity work asks more of someone whose motivation and energy may already be low, so knowing whether the payoff justifies the demand is a fair question. There is also the practical question of which kind of hard training helps most, since aerobic sessions, resistance work and interval training place very different demands on a person. This review pooled the randomised trial evidence to find out.

The authors searched four major databases for randomised controlled trials of high-intensity exercise in patients with depression, covering studies published up to 30 June 2025. Nine trials met their criteria, together enrolling 514 participants, 193 assigned to high-intensity exercise and 321 to control conditions. Depression severity was the main outcome, measured across a range of standard rating scales, and cardiorespiratory fitness was assessed via maximal oxygen uptake. They ran sensitivity and subgroup analyses to test how stable the findings were and to compare ages, programme lengths and exercise types.

High-intensity exercise groups improved more than controls on the Hamilton Rating Scale for Depression and on overall depression scores, a modest advantage in both cases. Several other scales told a quieter story: results on the HAMD, the Beck Depression Inventory and a pooled set of further scales did not reach significance, and maximal oxygen uptake did not clearly improve either. Subgroup analyses suggested longer interventions worked better than short ones, and adults aged 60 or older benefited more than those aged 30 to 60. Among modalities, high-intensity aerobic exercise showed the greatest efficacy, then resistance training, with interval training comparatively least effective.

This adds high-intensity training to the broader picture of exercise and mood, and the modest overall effect sits comfortably alongside what is known about exercise for depression generally. The inconsistency across rating scales is the complication: an effect that appears on some instruments and not others is harder to size with confidence, and the authors themselves flag small samples and unstable results. The modality ranking, with intervals trailing steady hard aerobic work, is an intriguing lead rather than a settled fact. Larger, better-controlled trials are the stated next step.

For someone managing low mood who already trains, this is a reason to think hard aerobic sessions may pull some weight for mental health as well as fitness, particularly over longer programmes. It is equally a reason not to expect intervals to do that job best, since interval training came out weakest of the high-intensity options examined. The effect was modest and the evidence uneven, so nothing here positions exercise as a replacement for proper care. It simply adds to the case that training and mood travel together.