Tone and strengthen your abdominal muscles with 8 quick exercises. How to work your abs in just 15 minutes? After the warm-up, do each exercise once; work your way up to two sets. Finish with the cooldown.

Start on all fours with hands directly beneath shoulders and knees below hips (top illustration). Exhale and contract your abdominal muscles, rounding your spine up to the ceiling (bottom illustration). Tuck in your chin slightly and hold for 10 to 15 seconds. Next, exhale and arch your lower back and draw your chest and head upward; hold for 10 to 15 seconds. Return to the starting position and repeat the full move five to eight times.

 Move 1: Bird-Dog

To work your six-pack area and back, remain on all fours and tighten your abdominal muscles, keeping your spine and neck in a neutral position; you should be looking at the floor (left illustration). Slowly extend your left leg behind you while reaching your right arm forward (right illustration).

Keep your hips and shoulders square and make sure your lower back doesn’t arch. Hold for five seconds. Slowly return to the starting position and do the move on the opposite side. Complete 5 to 10 repetitions on each side.

 Move 2: Stability-Ball Crunch

Strengthen your abs and obliques by sitting on a large ball with your feet flat on the floor (left illustration). Walk your feet forward, letting your entire back rest on the ball and keeping your thighs parallel to the floor.

Cross your arms over your chest and slightly tuck in your chin (right illustration). Contract your abs and exhale as you raise your torso about 45 degrees. Pause, then lower, inhaling as you go. If you feel unstable, move your feet farther apart. Repeat 8 to 12 times.

 Move 3: Front Plank

Lie on your stomach with arms bent, palms and forearms on the ground, fingers pointed forward, legs extended, and toes tucked under (left illustration). Work your back and abs by contracting your core muscles and slowly lifting your entire torso off the floor, keeping palms, forearms, and toes on the ground (right illustration).

Avoid arching your lower back, hiking your hips upward, or shrugging your shoulders (in other words, cheating). Hold for 10 to 30 seconds, gradually building up to one minute.

 Move 4: Bicycle

Lie on your back with fingertips behind ears, legs in the air, and knees pulled toward chest (left illustration). Target your sides and entire ab area by contracting as you lift your shoulder blades off the ground. Straighten your right leg at a 45-degree angle and rotate your upper body to the left, bringing the right elbow toward the left knee (right illustration).

Switch sides by straightening your left leg, bending your right leg, and bringing the left elbow to the right knee. Alternate sides in a pedaling motion. Complete 8 to 12 full reps.

 Move 5: Side Plank

Turn onto your right side with your legs extended and your feet and hips resting on the ground and stacked on top of each other (left illustration). Place your right elbow directly under your shoulder to prop up your torso, and align your head with your spine.

Gently contract your core and lift your hips and knees off the floor; this strengthens your sides and deep ab muscles (right illustration). Hold for 10 to 30 seconds, gradually working up to a minute, and return to the starting position. Roll onto the other side and repeat.

 Move 6: Reverse Crunch

To strengthen the entire ab area, lie on your back and extend your arms out to the side, or keep your hands behind your head if that’s more comfortable (left illustration). Raise your knees and feet so they create a 90-degree angle.

Contract your abdominals and exhale as you lift your hips off the floor with control; your knees will move toward your head (right illustration). Try to keep your knees at a right angle. Inhale and slowly lower. Repeat 8 to 12 times.

Cooldown: Cobra

Lie on your stomach with your hands underneath your shoulders and your fingers pointing forward (left illustration). Keep your neck long. Gently exhale and lift your chest and torso upward to stretch your abdominals (right illustration). Press your hips into the ground. Hold for 15 to 30 seconds, breathing evenly, then slowly lower back to the floor.

Source: Real Simple, Image Credit: Unsplash