GL's better butt workout: who's ready for your jelly? We are! Here's how to be bootylicious by swim season. No ifs, ands or butts about it.

Don't get us wrong: Any booty is beautiful, no matter its shape and size. That said, whether skinny or curvy, we all want our rear ends to be one thing--firm. Do GL's butt-lifting workout three times a week with at least one day between sessions. On off days, walk or hike briskly for 30 to 45 minutes, taking on as many hills or stairs as you can. In just four weeks, you'll go from wiggly to wow.

CHAIR SQUATS

1) Stand in front of a chair, facing away from it, feet hip-width apart. 2) Squat, keeping back straight, abs in and knees behind toes. 3) Let your butt lightly touch chair, then squeeze butt and stand up. Repeat for three sets of 10 repetitions.

LONDON BRIDGE 

1) Lie on your back on a floor mat, knees bent, feet on floor, arms at side. 2) Contract abs, and lift hips four to six inches. 3) Lift hips an inch more while pressing upper back against the floor, and hold for three seconds, then lower back to first lifted position. Do 15 repetitions.

BONUS ROUND Do the same move with right leg extended toward ceiling, making 20 small pulses. Switch legs, repeat.

DONKEY KICKS

1) Get down on all fours, and lift right leg back to hip height with foot flexed, knee bent 90 degrees. 2) Extend leg as if you were stamping the bottom of your sneaker onto the ceiling. 3) Return leg to hip height. Repeat for 30 reps before repeating with the left leg.

STEP-UPS

1) Place the right foot on a step or low bench, and push through the heel onto the step. 2) Keep all your weight on the right leg, then gently lower the left leg down, barely touching your toes to the ground. 3) Keeping the standing leg bent slightly at the knee to avoid injury, continue slowly while concentrating on working the right leg. Repeat 10 to 15 times, then switch sides.

BONUS ROUND Once that becomes easy, make the move harder by stepping up with your fight foot and lift left leg to hip height, knee bent 90 degrees. Hold for five counts and step back to start. Repeat 10 to 15 times; switch sides.

ARABESQUE 

1) Stand with your feet hip-width apart, right arm reaching up toward the ceiling. 2) Extend right leg back and lift it six inches from the ground, knee facing the floor and toes pointed. 3) Lower and repeat. Do 15 reps, repeat on the left.

BONUS ROUND Do this move but turn the extended knee to the fight when kicking back. Repeat the other side with the knee facing left. Do 15 on each leg.

DANCING LUNGES

1) Lunge forward with the left leg until your knee is bent 90 degrees, directly over ankle, right knee pointing toward floor. 2) Jump up, pushing off the floor with both feet. Switch legs in midair, landing with the right foot forward in a lunge position. Continue, alternating sides. Do three sets of 10 lunges.

ADVANCED! TOE GRABS

1) Stand about a foot away from a chair, facing away from it. 2) Lift your fight leg, and grab your foot in front of you with your fight hand, right knee bent. 3) Find your balance, then slowly bend left leg, bringing your butt toward the seat of the chair. 4) Straighten your left leg and return to starting position. You might need to bring your left arm in front of you to maintain balance. Repeat eight times, switch legs.

BABY GOT BACK!

Five surprising ways to get a butt that rivals Jessica Biel's

1 DRESS THE PART Want motivation? Keep that rear view in view. GL's editor Karen swears by working out in Nike's Dri-Fit tights. "They look great on anyone and keep you focused on what you're trying to improve."

2 USE WEIGHTS "You'll work your glutes harder and burn more calories," says Maggie Bass, an exercise physiologist. "Place a body bar or barbell across your shoulders, or hold dumbbells."

3 SLOOOW IT UP, SISTER "Rushing may get you done faster, but it also shortchanges your results," says Bass. Pretend you're in a pool--take at least four counts to lower into a squat, and then two to three to come up.

4 GET A BETTER BUTT ON THE WAY TO BIO Tone your tush while walking between classes. With each step, when one leg extends behind you, keep your heel on the ground as long as possible. When you do lift your heel, roll through your foot, then push off with your toes. Says Bass, "You'll blast your butt with every step."

5 FIND INSPIRATION Search online for a photo of a celeb who has a beautiful booty and a body type similar to yours. Glance at it for extra motivation. Says GL's Karen, "Staring in a mirror and analyzing everything you hate about your butt will never motivate you to change it--trust me."