The Best Circuit-Training Workouts
Works: core, chest, arms.
(A) Get in side plank position, resting on your right forearm (elbow under shoulder) and the outside of your right foot (stack your feet or scissor them on the floor). Lift your hips and press your arm into the floor so your body is straight and not sinking down. Extend your left arm up.
(B) Keeping your body raised, reach your left arm under you. Hold for one count; return to the starting position. Repeat for 30 seconds; switch sides.
Make it easier: Pivot with bent knees on the floor.
Make it harder: Balance on your hand instead of your forearm.