MUSCLES ENGAGED Obliques Many people put a lot of focus on working their abs but forget their surrounding neighbors; the oblique muscles. Obliques serve as stabilizers, and are used in almost every physical activity. Exercising your obliques should be a very important part of your workout program. Hamstrings The hamstrings play a crucial role in many daily activities, such as, running, jumping, walking and cycling. Strengthening your hamstring muscles help to protect your knees from injury by absorbing the stress placed on the knee. Weak hamstrings can lead to knee injury. Exercise Instructions Step 1 Start in a side plank position. Be sure that your elbow is directly underneath your shoulder and your feet are stacked on top of eachother. Step 2 Lower your body down until just before your hip touches the ground. Step 3 Raise your body back up into a side plank position using your underside obliques.