The Effects of the Isometric Exercise Plank

Even if you are a die-hard bodybuilder, you may still lack core strength. No matter how much strength training you engage in, it's important not to neglect your core by doing isometric exercises, such as the plank.

A woman performing a forearm plank in her living room. (Image: Wavebreakmedia/iStock/Getty Images)

Proper Form

To perform the plank properly, get down onto your stomach with your wrists directly under your shoulders. Push up while keeping your body straight from head to heels. Draw your shoulders down and back, but try to spread your shoulder blades out from your spine as you spread your collarbones out from your sternum. Press your thighs up toward the ceiling, and draw your tailbone down without allowing your hips to sag out of your body's alignment. Look down at the floor and hold for 30 seconds to one minute.

Variations

From the original plank pose, you can lift one leg so that it is parallel to the floor and hold for 30 seconds and repeat with other leg. You can also do the original pose on your forearms instead of your hands. If you don't feel strong enough to do the original plank, you can rest your knees on the floor, while keeping everything about the plank the same.

Benefits

The American Council on Exercise lists the rectus abdominis, transverse abdominis and erector spinae as the primary muscle groups that this move focuses on. In general, the plank pose strengthens the arms, wrists, spine and abdomen. To maintain the plank pose, you have to draw your abdomen up toward your spine; this action targets the deeper muscles of the abdomen that support the spine, says Charles Ennis, a personal trainer with his doctorate in physical therapy.

Tips and Warnings

You may shake after a few seconds of attempting this exercise. That is normal. Ennis recounts working with a muscular bodybuilder with lower back problems when working out. Ennis recommended some stretches and core training. Upon attempting the plank pose, this bodybuilder was shaking from core weakness within moments of beginning the exercise. If you can't hold this pose for 10 seconds, try dropping your knees to the floor from the original position. Once you can hold this modified plank for 30 seconds, do the full plank. If you have carpal tunnel or experience pain in your lower back when doing this exercise, stop immediately and consult with your doctor before proceeding with the plank pose.