If you want to exercise, you have to cut something else out - the time you spend exercising is time you're not watching tv/eating/sleeping/doing any of the bill

If you want to exercise, you have to cut something else out - the time you spend exercising is time you're not watching tv/eating/sleeping/doing any of the billion things that are more fun than sweating. For me that was the first thing I needed to get my head around. Once I kind of, well, knew the space was 'there', it was more of a case of missing the gym rather than missing doing something else for the gym. Secondly it was the realisation that missing exercise because I'm too busy with work is a false economy. After exercise I work harder and think sharper. The hour exercise costs me is more than made up for with productive work. In the times I've ditched exercise for multiple days / weeks, the compounded cost (slower work, worse sleep, etc) become even more evident. Other than that, it's just discipline and a good routine. Habits are hard to form and easy to break. Get to a point where you're upset with yourself when you break the routine.