How can a 13 year old gain muscle?
How can a 13 year old gain muscle? Once your muscles are loose, try a few basic exercises like these to help you get stronger.SIT-UPS. Lie on the ground with your knees bent and arms crossed on your chest. PUSH-UPS. Form a table on your toes and hands, with your hands shoulder-width apart. BODY-WEIGHT SQUATS. […]