A plank is an isometric exercise that strengthens and tones the muscles of the abdominals and lower back. It requires no equipment and little space, making it one of the easiest abdominal exercises to squeeze into your day.

When performing a plank, you should feel the work in your abdominals, glutes, and fronts of the thighs instead of the arms and lower back. All of these exercises are done in a plank position on your elbows and your toes. You can modify the exercise by raising yourself onto your hands or by dropping to your knees, similar to a modified push-up. Whichever version you choose, remember that your shoulders should be aligned and your body in a straight line without the pelvis too high or too low. The American Council on Exercise provides helpful instruction on how to perform a basic front plank.

Start by doing each of these plank exercises for 30 seconds. As you grow stronger, continue to add 15 seconds to your time. Once you work up to 1 minute, repeat each exercise to complete 2 to 3 sets.

Side Plank Rotation

From the elbow plank, come up onto your hands. Position each hand directly under your shoulder. Shift your weight to your right hand and rotate your left shoulder above your right shoulder. Raise your left hand into the air. Keep your body in a straight line from your ankles to your head. Rotate back to the starting position. Shift your weight to your left hand and rotate to hold the side plank on your left side. Continue alternating side planks throughout the exercise time.

Plank with an Arm Reach

From the elbow plank, shift your weight to your left arm. Extend your right arm out in front of you and tap the floor with your fingers. Return to the starting plank position and tap the floor with your left hand. Continue to alternate the arm reach and finger tap. Concentrate on holding the core tight, and keep your hips from rocking back and forth with the movement.

Plank with a Leg Lift

Keep your hips level as you lift your right toe off the floor, raising your leg about six inches. Return the right leg to the starting position and raise the left leg. Continue alternating leg lifts as you hold the elbow plank.

Plank with a Toe Tap

Shift your weight to your left foot, move your right leg towards the right, and tap your toe to the floor about six inches from the starting position. Return your foot to its original spot. Move your left leg out to the left and tap your toe. Continue to alternate toe taps from side to side as you hold your core muscles tight.

Sources

• American Council on Exercise - Reality Check: Are planks really the best core exercise?

Lori Rice, M.S., is a nutritional scientist and author with a passion for healthy cooking, exercise physiology, and food photography.