Tennis requires a lot of explosive power, strength, and endurance. You have to have strong core, hips, and legs to be able to load and coil, and then uncoil into the shot. An excellent tool to improve your tennis specific fitness is kettlebell training. They work your legs, hips, and core and shoulder stabilizers simultaneously. A basic kettlebell swing will get your heart rate to heights equal with running 8-minute mile.

You need a kettlebell that is not too light for you or you will develop bad habits, such as using muscles in your arms and shoulders to “muscle” the kettlebell up and down instead of swinging and using the momentum. If the bell is too heavy, then it can be difficult to develop a good technique. Men can start with a 35-pounder and transition to a 45-pounder, women can start with 26-pounder and transition to 35-pounder. Another option is to do more repetition with the lighter weight -- 10 sets of 35 repetitions with 35 lbs kettlebell will be pretty challenging.

Always make sure that your chin and chest are up, and focus your eyes on something in front of you. Your lower back should be neutral or slightly arched, but never round. Open your legs slightly wider than your hips and let the kettlebell hang between your legs, with your chest and chin up. Bend your knees and push your glutes back. To start the swing, explode with your hips forward in a quick powerful movement, almost as if you want to hit an imaginary wall in front of you. This movement will shoot the kettlebell upward. Hold the kettlebell loosely and keep your arms and grip relaxed. When the kettlebell reaches the top, let it drop on its own, don’t resist the free fall with your arms. Contract your core, stick your glutes out, and when the bell reaches the bottom position, immediately explode into another swing.

Never let your chest fall down or your back get round. Keep your posture erect at all times. If you snap your hips correctly with power, you will experience a tiny “shake” of everything in the front of your body. Practice this basic swing until you develop an effortless movement and technique. You will feel very soon that your hamstrings, glutes, core, forearms and the grip will get much stronger.

Once you master the basic swing technique, you can practice one-handed swings, switching the hands at the apex of each swing. The hand switches will teach you to hold the kettlebell loosely and relaxed, or it will be too hard to switch the hands. When you can handle the one-handed swings easily, you can proceed on flips -- at the apex, release the bell and let it rotate 360 degrees, then grab it quickly before it falls. Continue the movement into another swing. When you get better on flipping, you can flip the bell each swing at the apex. Learn how to flip it with underspin or topspin, with two hands or one-handed. Never rescue a bad flip. Rather let the kettlebell fall (move your feet quickly!) and then pick it up and start another swing. In the beginning, you will have a lot of unsuccessful flips, and that is a part of the process. You will need some patience to learn how to flip effortessly, but it is going to be extremely fun when you finally master it.

For more kettlebell exercises for tennis, inspiration or injury prevention, visit www.TennisFitnessLove.com.