This is a Gym Summary from the book called "Life Fitness".

Safe and Smart Physical Activities It is important to be prepared for physical activity. A beginner needs to be medically ready. Anyone should be ready for extreme physical conditions, self assessments, and injuries. One of the most fun and important forms of physical activity is games. You can obtain physical fitness by playing games. Before you start a game or a sport, you should make sure that you are medically cleared. That may mean that …

…and donkey kicks. Also, avoid joint twisting, compression, and friction such as in exercises which cause the joints to more too far in one position, like double leg lifts, standing windmill toe touches, and arm circling with palms down. Improper strengthening or stretching exercises can cause muscle imbalance. These include forward arm circling, double left lifts, and straight-leg sit-ups. Safe exercises are Curl-up, reverse curl, back-saver hamstring stretch, hip and thigh stretcher, and knee-to-nose touch.