Getting a six-pack set of abs etched onto your torso isn't just good for admiring glances at the pool. Your abs play a role in stabilizing your spine, maintaining a healthy, neutral posture and protecting you against common injuries. To make your abs bigger so they pop visually, focus on working them just like you would any other muscle. For the best results, choose several exercises and do them one or two days a week -- more than this, and you risk overtraining and you won't see the gains you want.
Mimic a Spider's Crawling Movements
The spider plank crunch is one of the few ab exercises that hits your entire core, including your abs, obliques — the strip of muscle running vertical next to your six pack, often known as "side abs" — and your lower back. Not only does working your abs make them bigger and stronger, but this workout's ability to hit your whole core also helps prevent muscle imbalances between your abs and back. To do the spider version of the plank, get into the starting position for a traditional plank with your spine straight, legs pressed together resting on your toes, and upper body resting on your forearms with your elbows bent at 90-degree angles. While keeping your abdomen contracted and firm, lift your left foot off the ground and bring your left knee up toward your left elbow. Pause, then return to the starting position. Repeat again, this time with your right knee moving up toward your right elbow.
Ride an Imaginary Bicycle in the Air
The American Council on Exercise studied 13 common ab workouts and discovered that the bicycle crunch worked the ab region the best out of all the exercises. Unlike the traditional crunch, the bicycle crunch involves a twisting motion in your abdomen, which helps work your upper abs, lower abs and obliques for overall strength and size gains. To do the bicycle crunch, lie on your back. Put your hands behind your head, and raise your legs so your feet are in the air and your thighs are making a 90-degree angle with your torso. Tighten and contract your core, then lift your shoulders and upper back slightly. Twist gently and bring your left elbow and your right knee together, then return to the starting position and repeat with your right elbow and left knee. The action your legs make should mimic riding a bicycle.
Grab a Cable and Do the Twist
You'll need a cable machine for this workout. The twisting motion, combined with the resistance from the cable, engages your obliques for better side ab definition and size. Hold a cable in front of your chest with your arms straight and your hands positioned just slightly lower than your shoulders. Tighten your core and, without moving your hips or legs, twist to the right and then to the left. Your arms should always be straight and not sway in relation to your torso, thus making your abdominal muscles and obliques do all the work.
Play in the Captain's Chair
The captain's chair workout is the second most powerful ab exercise, according to the ACE 13-workout comparison. Also known as the power tower in some gyms, the captain's chair consists of padded arm rests that are high off the ground. Get into the chair facing forward with your back pressed against the chair's back and your forearms resting on the arm rests. When in this position, your torso should be straight with your legs dangling in the air. Contract and tighten your abs and, without moving the rest of your body, lift your legs up and forward so your thighs make a right angle with your torso. Pause for a second, then return to the starting position.
Crossover to the Cross Crunch
If the spider crunch balancing act or the captain's chair elevation make you wary, try the cross crunch. During this workout, you're planted firmly on your back, which is safe for most people with balance problems or fears. This exercise is key if you're looking to make your lower abs bigger and more defined. Lie down with your legs straight and arms spread out so you're body makes a cross shape. Tighten your core and bring your left foot into the air while reaching toward it with your right hand, then return to the starting position. Repeat with the opposite side, pointing your right foot into the air above your body and reaching toward it with your left hand. While this exercise is lower-ab specific, it also works your entire core due to the general movement and slight twisting of the torso.