The plank is an isometric core-strengthening exercise that requires your abdominal muscles to contract and hold your body in a set position. The body position is designed to be held for time. The plank primarily targets your rectus abdominis muscle, which runs up the front of your torso from your pubis bone to your sternum. The traditional plank is effective at developing isometric strength of the rectus abdominis, but there are modifications you can implement to increase the difficulty and incorporate instability.
To perform the traditional plank, lie on your stomach on a mat with your legs extended and your elbows placed directly underneath your shoulders. Rise up onto your forearms and toes, creating a straight line throughout your torso and legs. A common mistake involves your bottom being held up, placing you in a slight V-shape position, which decreases the demand on your abdominals and makes the exercise easier. On the other, don’t allow your stomach to sag toward the floor by contracting your abdominals. Once your stomach begins to sag or you feel yourself raising your hips up toward the ceiling, lower down and stop the exercise.
Increase the difficulty of the plank by adding small toe lifts. From the plank position, while keeping your legs straight, lift your right toe a couple inches up off the floor and then return it to the floor. Then, lift up your left toe. Alternate back and forth between legs while simultaneously maintaining a solid plank position. This adds an increased element of instability, as lifting your toes shifts around your center of gravity.
Even more challenging than the toe lifts version of the plank is the Spiderman plank. While maintaining the plank position, pick up your right leg and rotate your hip so you can bring your right knee up toward your right shoulder. Extend your leg back down to the floor and then switch sides, bringing your left knee up toward your left shoulder.
Hands on Ball
The plank can also be completed while placing your hands atop a medicine ball. Instead of resting on your forearms, your arms are extended with the small medicine ball positioned direction underneath your shoulders. In addition to the work your abdominals perform to hold you in the plank position, the collection of rotator cuff muscles contract to stabilize your shoulder joints.
The side plank focuses on your oblique muscles that run along the sides of your torso. Lie on your side with your legs stacked on top of each other. Set your elbow directly underneath your shoulder and rise up onto that elbow and on the sides of your feet, creating a straight line through your legs and torso. Be sure to perform the exercise on both sides.
Kim Nunley has been screenwriting and working as an online health and fitness writer since 2005. She’s had multiple short screenplays produced and her feature scripts have placed at the Austin Film Festival. Prior to writing full-time, she worked as a strength coach, athletic coach and college instructor. She holds a master's degree in kinesiology from California State University, Fullerton.