Want a move that simultaneously works your abs and back? Try this boxing move from Crunch NYC instructor Christy Nacinovich.

How to do it: Begin standing with your knees bent slightly, feet in fighter’s stance (left foot forward). Raise both your arms up and to left as if grabbing something. Engage your core muscles and pull your hands down as you bend your right knee and lift it up to meet your hands. Return to previous position, tapping right toes to the floor.

Continue for 10 reps before switching sides and repeating. Do two sets, three to four times a week.

Try this move: Knee Strike

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