I'm not a workout guru, but I've learned through trial and error that it helps to do quick, simple, effective light workouts. Light workouts that you can do anywhere, any time and don't take up a lot of space and time. Do enough to break a little sweat. This way you'll be able to keep a schedule and stay fit. Do the heavy workouts when you can. You won't feel like you're cheating yourself or anything if you can't always do the heavy workouts.