Lie on your back with your knees bent and feet planted on the floor. Abs tight, lift hips until your body is in a straight line from your knees to your shoulders, supported on your feet and upper back. Hold for five seconds, then slowly lower to start. Do 10 reps. For a greater challenge, extend one leg straight as you lift and lower, working to keep your hips level (don’t let hips dip to one side or the other).
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