For me, Motivation is the issue. I was 18 and 12 stone and under 10% body fat, went to the gym five nights a week and done kick boxing the other two. I also cycled to and from work, I was in such good shape. Started driving buses when I was 18, now 26 and drive trucks I am just over 17 stone. Now my only exercise is walking the dog and unloading the truck, every now and again I take up jogging or cycling, never lasts though 