This move adds an extra challenge to the traditional straight-arm plank.
Start in a traditional straight-arm plank position. Widen your legs for more stability, if needed.
Keeping your core tight, lift your right hand off the floor and touch your left shoulder. Then, return your right hand to the floor.
Lift your left hand and touch your right shoulder.
Continue to alternate hands for 20–30 seconds.
Avoid rotating your shoulders or hips during this movement. The goal is to keep your body in a straight line.