Tighten Your Glutes in 15 Minutes

Toned gluteal muscles help put pep in your step and reduce stress on your knees. To strengthen your rear end, use the following quick isometric exercises from JB Berns, a personal trainer in New York City and the author of Do It or Age Quickly ($25, amazon.com). Repeat each move four to eight times, then run through the routine once more.

Begin in a wide squat. Push off the ball of your right foot and squeeze and contract your entire leg and gluteal (rear end) region. Hold for four seconds. Repeat on the left side.

Stand with your legs shoulder-width apart. Squeeze your glutes as tightly as you can for four seconds.

Stand next to a wall or chair and rest one hand on it for support, if needed. Lift your right foot toward your rear for a hamstring curl. Hold the contraction for four seconds. Repeat on the left side.

Start with your legs shoulder-width apart. Lift your right leg behind you at a 45-degree angle about six inches off the floor and point your toe. Squeeze your glutes for four seconds. Repeat on the left side.

With feet shoulder-width apart, raise your right leg to a 45-degree angle. Cross it in front of your body and point your toe. Hold for four seconds. Repeat on the left side.

Sit in a chair with your feet on the floor. Make a fist with both hands and place them between your legs. Resisting with your fists, squeeze your legs inward for four seconds. Next, move your hands to the outsides of your thighs. Push your legs outward, using your hands as resistance. Hold for four seconds.