Should psychiatrists be treating patients with "sport" ?

since doctors get big incentives to pawn off medications for drug companies its not in their best interest to prescibe something that is free however depression always has this laziness effect you cant even get out of bed let alone run a mile i think that someone on anti depressants when they feel good should be told to exercise so the doctors can ease them off the drugs slowly because exercise makes the body release endorphins which helps raise serotonin production in the brain which is the reason depression happen...so yes they should be prescibing sport to some patients