Exercise treats low mood about as well as medication or therapy across more than 200 trials, and harder exercise works better than gentle. Walking, running, lifting and yoga all show up as effective. Evidence: solid
The testosterone story you've heard is weaker: training does raise it briefly, but the lasting effect on drive and mood comes from the exercise itself, not the hormone spike. Evidence: decent
Consistency beats intensity. Three moderate sessions you'll actually do beat one heroic one.
Same theme: Moving
Moving
Lower the bar for the gym
On a day you'd skip, the session is ten minutes. Same time, same place, bag packed the night before.
10 minEvidence: decent
Moving
Rehearse the lift in your head
Injured, travelling, or stuck at a desk: fifteen minutes imagining the exercise, as vividly as you can, muscles included. Most days.
15 minEvidence: decent
Moving
The if-then plan
Turn a goal into a trigger and an action. "When I get home Tuesday and Thursday, I change and go to the gym before I sit down."
2 minEvidence: solid