Prison Cell Exercises
I got my ab workout from watching a "Dirty Jobs with Mike Rowe" podcast. Someone wrote in asking how he keeps fit while constantly on the road. He explained that he learned an effective exercise that could be performed without equipment and in a confined space, like a prison cell... or hotel room.
You begin in a standing position, squat down, kick your feet back to bring your body to a push-up position, complete one push-up, return to a squat, stand, and jump. You complete one set of 10 reps and take a one minute rest. You then complete a second set of 9 reps and take another one minute rest. Continue with a total of 10 sets, reducing the number of reps by one for each consecutive set.
I usually run through this exercise 3 times a week and walk the other 4 days. While I thought that this would mostly strengthen my arms and legs, I was surprised about how much it helped with ab strength and definition.