Primary Muscles: Obliques Deep abs, Back muscles
Your torso should be bent at about a 45 degree angle to the floor, back straight. Keep your feet together throughout the exercise and your arms locked and level with the bottom of your ribcage. Your feet can be kept flat on the floor, or for a more challenging exercise, hold them slightly above the ground. The slower you twist the harder the exercise becomes. When moving your arms, try not to stop between reps and remember never to hold your breath.