Forearm Side Plank Love them or hate them, planks pack a lot of power! This move specifically targets the obliques and improves shoulder stability, DiGiorgio notes. Come to a side forearm plank on the right arm, stacking your hips. Reach your left arm long by your ear. Float your left leg. Slowly bend your left knee to your left elbow then slowly extend both. Repeat for 30 seconds. Rest for 10 seconds and repeat on the other side. Image Source: Pure Barre