I agree that he has naturally poor stamina and gaining weight will only ever make that a hell of a lot worse. If I was in his shoes I'd go on a three-four month high altitude training 'sabbatical' away from the boxing world with the intention of getting as fit as is humanely possible. Keep up the boxing training and throw in some Olympic weightlifting a few times a week and he'd be in the best shape he could be in. If that doesn't give him the ability to last at least 8-9 rounds without looking completely arseholed then it's time to hang up the gloves.
