Move your body when your mood is low
Comparable to some first-line treatments for mild to moderate depression, and free.
Do this
Aim for moderate aerobic exercise most days - brisk walking counts. Consistency matters more than intensity. If motivation is the obstacle, shrink the commitment until it is trivially achievable and let the effect build.
Why it works
Multiple meta-analyses find meaningful reductions in depressive symptoms from structured exercise, with effect sizes in the moderate range. Mechanisms likely include neurotrophic factors, sleep improvement, self-efficacy and behavioural activation - probably all of them together.
Where it fails
It is not a substitute for treatment in severe depression, and the message 'just exercise' does real harm when delivered to someone who cannot get out of bed. Trial quality in this literature is uneven and publication bias is likely, so treat the largest reported effects with caution.
How you’ll know
Track mood weekly rather than daily. The signal is a lifted floor across weeks, not a good feeling after a session.