The Best Circuit-Training Workouts
Works: legs, rear, core.
(A) Stand with feet shoulder-width apart, fingers interlaced behind your head. Keep your elbows wide and your chest high.
(B) Lower into a squat, bending your knees about 90 degrees and keeping them aligned with your toes (don’t let them angle in or out). Rise and repeat.
Make it easier: Don’t squat as low.
Make it harder: Do one prison squat on one leg.