Tennis: Strengthen your entire body like Venus and Serena Williams!
Tennis is a side to side sport, so what better workout is there than side to side planks? Core strength is necessary for just about any sport, and this will work your arms and legs, too. Start in a push-up position, then turn to your right side and lift your left arm to the ceiling. Hold your body tight, resembling a "T" for 30 seconds (or as long as you can manage). Come back to push-up position, then do the same thing on the other side. Repeat at least three times.
