Sprints are a very efficient way to improve athletic performance and keep the entire body lean and strong.
How to do it: Start in a lunge position with your back at a 45-degree angle, weight shifted forward. Drive through your big toe to take bounding steps forward. After about 10 yards, rest for 30 seconds before starting your next sprint. Quickly shift your hips forward to repeat the forward movement again. Do 5 sprints.