The guide that every locker room and gym bag should have. Alter, a dancer and exercise teacher, has managed to put in the clearest, simplest terms the purposes of all exercise, as well as the dangers and how to avoid them. ""In order for your body to thrive--to enable you to do whatever you want whenever you want--you need to provide your muscles with a balance of stretching and strengthening activities."" When an imbalance exists, injury occurs; so her recommendations are directed toward correcting the common imbalances. Equally sane are her ""key instructions for surviving exercise."" Before and after any activity: stretch muscles that have been strengthened (and hence contracted); strengthen stretched muscles; stop any and all activities if they hurt (Alter can even describe what real hurting is); learn to perceive and attend to muscular sensation. Above all: ""be guided by the inherited and developed limits of your body."" Included are specific exercises for the most important muscle groups and a list of common but injurious exercises (all ""bouncing"" stretches, the yoga ""plow"" position, etc.). The best available warm-up guide for all levels and fields of endeavor--and a strong argument for sensible exercise generally.