Though similar to squat jumps, prisoner squat jumps focus more attention on the core, making this a great overall cardio exercise. By placing the hands behind the head and leaning the torso forward, you engage the abs and the back, which challenges the core. This is an advanced exercise that is high impact, so protect your joints by landing with soft knees. If the impact is too much, you can do the move without jumping. If you've never tried this move, take your time and ease into it with small jumps. If you feel discomfort or pain, avoid this exercise.