One help might be to use our tendencies for habits, routines, and addictions to our advantage. Pick a day and time, or if your shifts always change, a pattern that would work.

For me, I am not a great exerciser. But twice a week is a start. So, for me it is now routine to look out of the window Saturday and Sunday mornings right after I wake up, and if it isn't pouring rain, snow or ice, I go walking. If I forget, I feel the guilt of a missed opportunity, a missed appointment. Do whatever you need to do - walk, curves, gym club - but get into a routine.

THink about when you might most easily get into such a routine. If you have 3 shifts, there is always a morning after 24 h break, so pick that morning, for example, as your routine: Whenever I am off 24 h, that morning is my walk/gym day. Or maybe the morning after you have slept and still have the whole day off - whatever works, but then make it your rule. Good luck!