Mixed Martial Arts has become a multi-billion dollar global industry, but many athletes taking part at a professional level keep a dark secret about their training. Weight cutting is a dangerous activity that has claimed lives in the sport even before the fighters stepped into the cage. This documentary follows Dean, a British MMA fighter, as he cuts 7kg of weight overnight using saunas and hot baths to hit his weight category to fight. Whether he makes it or not, this film examines how the unhealthy practice of cutting weight could affect his long term health forever. Part of a series of BBC Three programmes exploring Extraordinary Bodies.