HBO’s “Real Sports with Bryant Gumbel” tonight examines how some military veterans are combatting post-traumatic stress disorder (PTSD) with a seemingly unlikely activity: MMA training. The episode, which airs at 10 p.m. ET/PT, focuses on POW MMA Fight Club in San Diego, where war veterans say they find relief from the condition due to the camaraderie and intense training. Reporter Soledad O’Brien hosts the segment. Check out a preview clip above. “Real Sports,” which also profiled champ Ronda Rousey in February ahead of her UFC debut, airs replays of tonight’s episode throughout the week on HBO’s various channels and on demand.