No buts about it: Having a toned tush makes everything fit better, from your favorite jeans to the swimsuit you'll be rocking this summer. And even though it's tough to see your backside without a full-length mirror, 14 percent of SELF readers rate their rear as the favorite part of their body. So what's the best way to get a firm, fit, downright amazing derriere?
SELF's tush tightener, which activates your butt muscles nearly 40 percent more efficiently than traditional butt moves like lunges (though we love a good lunge, too). Here's how to try it: Balance on right side with legs stacked, right hand supporting head, left hand resting on floor in front of chest. Squeezing butt, raise left leg 2 feet, foot flexed. Flex bottom foot; lift bottom leg to meet top leg; pause; lower one leg at a time for one rep. Do 12 reps; switch sides; repeat. To make it easier, lift and lower only top leg. To make it harder, hold a 5- to 8-pound weight on top thigh. For a demo of the move and instruction by SELF fitness director Meaghan B. Murphy, sign up for the SELF Challenge.
Jillian Michaels, trainer extraordinaire and new SELF contributor, also thinks jumping lunges are a fantastic firmer. "They just blast the heck out of your glutes while working hamstrings and other muscles in the legs." Try this sequence one to three times a week after your usual cardio plan. Quickly do one set of the indicated reps of each move; rest 90 seconds. Repeat up to two more times.

MOVE 1: 20 squats
MOVE 2: 20 lunges, alternating legs
MOVE 3: 20 jumping squats (in a fluid movement: squat, jump, squat)
MOVE 4: 20 jumping lunges (lunge forward with right leg and jump high. While in the air, switch legs and land with the left leg in front. Continue, alternating legs.

If you have knee problems or any lower-body injury, try step-ups, which tone glutes 59 percent more than squats, according to a study by the American Council on Exercise in San Diego. To try, hold a 5- to 8-pound dumbbell in each hand, then step left leg onto a bench. Step down on right leg. Do 12 reps, and go slow to avoid injury. Switch legs; repeat.