7 Best Swimming Strokes and Exercises for Working Abs

Trying to tone your stomach through swimming workouts? It's virtually impossible not to work your abs when you're swimming, because you need to engage core muscles to stay afloat and move through the water. You'll also burn 400 calories or more per hour, which targets belly fat. But focusing on certain strokes will put more emphasis on your upper and lower abs, as well as those love handles.

Because the backstroke and freestyle (aka "the crawl") are virtually mirror images of one another, it's not surprising that both strokes engage the same muscles. When it comes to your core, the specific muscles that get worked are the rectus abdominis, known informally as the six-pack when toned. The external obliques, which are your side abdominal muscles, are also worked.

Both strokes require that you first reach out with one arm and then the other. Those alternating actions must be stabilized by your core to keep you from literally swimming in circles. Of course, as each arm slices through the water, your side abdominals are assisting those reaching motions.

Your lower abs are particularly well-worked by the kicking motions required by freestyle and backstrokes. The strong kicks used in both strokes start from your lower abs and hips.

The butterfly stroke is one of the most challenging swimming exercises. Of course, arms and shoulder moves are used to lift the upper body out of the water. Yet you also need your entire lower body, including the ab muscles, to propel your torso out of the water.

The challenging dolphin kick used in the butterfly is also responsible for making the stroke a superior swimming abs workout. The rectus abdominis provides the starting motion for the undulating leg moves used in the dolphin kick.

Read more: 12 Moves for a Stronger Core and Better Posture

Using the kickboard to immobilize your arms while swimming laps forces your lower body to do all of the work to keep you afloat and moving forward. By keeping the kickboard at arm's length (rather than resting your upper body on it), your abs need to work harder to stabilize your rocking form.

To make kickboard laps a particularly strong move for your swimming abs workout, focus on drawing your stomach inward. Visualize your belly button drawing toward your spine, as your core works on stabilizing your body. Kick your legs to propel you forward and do as many laps as you can manage before becoming fatigued.

If the pool's too crowded for lap swimming workouts, there are still swimming abs moves you can do. Among the best swimming exercises for the core are:

• Flutter kicks. Hold on to the side of the pool. Kick your feet behind you, keeping your legs straight. Alternatively, use a kickboard or pool noodle to stay afloat so that you're vertical in the water; then begin scissor-kicking your legs rapidly, with your toes pointed to the bottom.

• Side bends. To work your abs and your obliques, stand in the water about waist deep. Keeping your arms hanging straight down, bend sideways until your arm is about halfway submerged. Straighten, switch sides and repeat. Keep your core engaged throughout these moves.

• Jackknife moves. In this move, you'll go from lying on your back on the water, to a "V," by bending your knees to your chest and then straightening them so that your toes point upward. Keeping your arms behind you and in circling motions to stay afloat, engage your core to hold the position for a three-count. Lie flat to rest; then repeat up to 10 times.

Read more: The Cardio Abs Workout