Abdominal crunches have long been a staple of many people's workouts. Crunches have been credited with helping to reduce belly fat and sculpting the perfect midsection.
But sit-ups and crunches have never been the optimal exercises for developing strong abdominals. Each exercise requires more strength from the front of the abdomen than the side oblique muscles. This can cause a strength imbalance that may lead to back problems down the road. According to research from San Diego State University, the traditional crunch is the least effective way to strengthen the rectus abdominus as well as the obliques.
Many people do not adhere to proper form when doing crunches. Performing crunches in an unsafe manner may lead to more than a few sore muscles, as it's easy to slip a disc in the spine or pull muscles that result in problems that may not show up immediately. Crunches also can reinforce bad habits that can result in poor posture.
Crunches may be one way to sculpt impressive abs, but they may not be so effective at targeting the inner abdominal muscles that really lead to a strong core. It's important to do exercises that also will target the transversus abdominus muscles, the innermost flat muscles of the abdomen.
Several other exercises are more effective at working the core muscles without causing the back strain associated with crunches.
• Planks: Planks help stabilize the core and require more muscle activation in the obliques than traditional crunches. Practicing this position also can help lower the risk of lower back pain because it targets the abdominals while putting no pressure on the spine. Planks require no specialized equipment. To perform a plank, hold your body in a pushup position while resting on bent forearms. Hold your body in a straight line and pull in your stomach to create tension in the midsection. Keep the plank position for as long as possible. Vary the regular plank with side planks to target obliques.
• Leg raises: Leg raises isolate various ab muscles. You can raise legs only a few inches off the ground and hold or alternately lift the legs to a 90-degree angle and slowly lower. Experiment with different variations of leg raises, such as scissoring or rotating the feet, for even more resistance.
• Vertical crunches: Instead of lying on the floor to perform crunches, hang from your arms or hands on a pull-up bar to take pressure off of the spine. Get into the hanging position and then draw your knees up into the chest. Lower knees and repeat. An alternative is to lift the legs with legs extended instead of knees bent.
• Woodchoppers: This exercise puts your body in the same position it would be in if you were chopping wood with an ax. It can be performed using a cable machine or a medicine ball. Begin by holding the ball or cable handle up high and with both hands, then pull down to the opposite side of the body while rotating your torso and pivoting hips in the direction of the turn. Repeat a few times and then switch to the other side of the body.
• Dragon flags: A dragon flag is essentially a leg lift in reverse. Made popular by martial arts master Bruce Lee, dragon flags start with men and women lying on a bench or the floor where they can grab onto something near their heads. Keep your shoulders and back planted to the bench. Slowly lift your legs in the air and then lower back down. Dragon flags require time and conditioning to master but can effectively sculpt abdominal muscles.