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. Triceps Triceps are an often forgotten muscle group. Triceps are located on the opposite side of the biceps at the back of the upper arm. Well strengthened and defined triceps make the arm look bigger and sleeker (reducing the "flabby arm" look). Exercise Instructions Step 1 Start in a side plank position. Have your elbow directly below your shoulder and your feet stacked on top of each other. Step 2 Lower yourself to the ground but don't touch your hips down. Step 3 Drive your hips back up and fully contract your obliques on the underside.