The ability to pump oxygen around the body is the first thing to go. The heart can’t beat fast enough to feed the grinding pistons. Fast-twitch muscle fibres start to deteriorate. Speed, power and agility lose their snap. Energy reserves deplete. Muscle mass retreats. Then there’s the aches and pains, the stiff limbs and creaking joints. This is the harsh reality for each of us as we enter our 30s but, for elite footballers, this is nature sapping their superpowers. Fighting against it is fut...