The UK’s toughest workouts

 Up for a challenge? Prepare yourself for the UK’s toughest workouts.

Want to push your body to the absolute edge of its physical ability? According to experts, the most brutal of workouts can change your metabolic state dramatically, altering the way you store and use fat and doubling the calories you burn. So if pain and suffering is your idea of a successful workout, here are five of the UK’s toughest.