Gentle exercise yes, like going out for a walk. Just focusing on the sights and sounds encountered on the walk and the feeling of walking, not on the thoughts in my head or the emotions I’m experiencing. Strenuous exercise was not useful, it just left me exhausted with none of the positive effects that gym-rats talk about. However, and its hard to be certain about this because I’ve not monitored it in a scientific way, regular exercise does seem to help prevent me from falling back into depression once I’ve climbed my way out.