Sprinter Starts - This exercise is designed to get your heart rate up. Start with a plank position and bring one foot forward. The faster you go, the more intense the exercise is. Ensure you keep your body level (no butts in the air).
OPTION: Low impact - move one leg at a time, keeping one foot on the ground at all times. 2nd option is to do this on your knees and tap one foot back (straighten your leg behind) keeping your hips steady.
STOP IF YOU FEEL DISCOMFORT IN YOUR LOWER BACK.
IF YOU HAVE A LOWER BACK INJURY, SUBSTITUTE THIS EXERCISE FOR YOUR REHAB EXERCISES