Strengthening exercisesa such as push-ups, crunches, and lifting weightsa make your muscles bigger and stronger. Flexibility exercisesa like stretchinga make your muscles and joints flexible and help prevent injuries. Ita#39;s a good idea to doanbsp;...
|Title||:||American Medical Association Boy's Guide to Becoming a Teen|
|Author||:||American Medical Association, Kate Gruenwald Pfeifer|
|Publisher||:||John Wiley and Sons - 2010-12-08|