Luckily I like exercising. Esp weight lifting. Even when i'm not at the gym I think of ways to improve my workout. I've made progress too but not as much as I want. Anyway at firt it was hard getting myself to go to the gym. Then I allocated a time to workout and even if I wasted a few minutes of that time I would still exercise for the remaining period. This way it became a habit than a task and before long I started feel shitty if I couldn't workout.