The lunge is a great multitasking move -- it targets the abs, butt, quads, and hamstrings all at once. With feet together, slowly lift the right leg and step forward, placing your right foot firmly on the floor. Lower the hips until your right thigh is parallel with the floor. Make sure your right knee doesn’t push forward in front of your toes. Slowly return to standing. Aim for eight to 12 reps, and repeat on the other side.