Warm up for 10 minutes with light cardiovascular exercise before your tennis practice session or match. Riding a stationary bicycle, using the elliptical trainer or light jogging are effective ways to raise your body temperature and increase the blood flow to your muscles. Follow the cardio with five to 10 minutes of hitting groundstrokes, which are the forehand and backhand. End the warm-up session by practicing serves for three to five minutes.
Develop a steady breathing pattern to help your muscles relax; your form and body alignment can suffer from stiff muscles. Inhale through the nose and exhale through the mouth for a count of two to three, in each direction.
Place your weight on the balls of your feet with your feet separated by hip width so that you are ready to spring forward toward the ball. Keep your knees bent and your torso slightly forward, such as you would in a half squat. This puts you in the ready position; after every shot, return to the ready position to be in proper position to hit the next ball. This stance allows you to quickly move in any direction necessary -- forward, backward or side to side -- to reach the ball.
Engage your core. In tennis, your power, stability and balance all come from your core. Pull your abdominal muscles in toward your spine; keep the abs contracted throughout the practice session or match.
Hold your back straight, with shoulder blades pushed down and away from your ears. Avoid arching your lower back or hunching your shoulders. Elongate your spine and maintain a neutral neck so that you are able to keep your eye on the ball at all times.