The end of sit-ups?

A well-defined midsection with impressive abs is the goal for many people who work out. This is especially the case at this time of year, when you can take your shirt off at the beach - and hopefully show off a washboard stomach that looks like it was chiseled out of stone. Unfortunately, I still see so many people in the mat area of the gym doing sit-up after sit-up, expecting to develop a slimmer waistline with defined abs. Sit-ups are also traditionally used to develop strength and stability in the muscles of the core. Since the core is the center of the body, a strong core is able to transfer force through the body more efficiently during exercise, supporting greater force production and muscle growth. In addition, the muscles of the core are activated during the execution of many movements of sport, meaning that a stronger core also enhances athletic performance, which is another reason to desire a stronger core (1).

Although sit-ups may intuitively seem like the best way to develop defined abs and more core strength, there are better training modalities that activate all the muscles of the core more effectively (2). These other training modalities ultimately result in better abdominal muscle development and the coveted six-pack, as well as more core strength for better overall body strength and athletic performance.

Another benefit of a stronger core is a reduced risk of injury. This is the case because a stronger core has a greater capacity to stabilize the joints and soft tissue around the core, while also promoting better movement patterns that reduce the likelihood of injury occurring (3, 4). In addition to the relative inability of sit-ups to develop core muscles, performing sit-ups could also be harmful to the spine. The potential to injure the spine is based in part on the activation of the hip flexors (a muscle group that runs from the thigh bones to the spine in the lower back) during the initial phase of the sit-up movement, which exerts a substantial compressive force on the intervertebral discs. The higher compression forces exerted on the discs increase the risk of disc herniation, where a disc can press on a nearby nerve, causing significant pain. Other concerns regarding injuries that may be associated with sit-ups have to do with the fact that the repetitive bending of the spine while performing sit-ups could lead to wear and tear on the spine over time, which can cause chronic pain and injury (3, 4).

As a result of the numerous disadvantages associated with sit-ups, you may want to rethink your entire approach to core training and utilize some more effective and safer exercises mentioned later in this article. The exercises I will describe generate superior activation of the muscles of the core, providing a more powerful training stimulus that will create a much stronger and more defined core.

Better abdominal exercises

Two alternative exercises for the core that have been shown to significantly increase the activation of the abdominal muscles and obliques and should therefore be performed instead of sit-ups are power wheel roll-outs and hanging knee raises. For power wheel roll-outs, start with your knees on the floor and a barbell bar in your hands on the floor directly in front of your body, very close to your knees. From this position, extend your body forward by rolling the barbell straight ahead while maintaining a straight spine and pelvic posture throughout the movement. When a full extension is achieved, simply reverse the movement until the bar is back in the starting position, directly in front of your knees.

In the hanging knee raise, the body hangs vertically downwards in the starting position, with the torso, hips and knees fully extended. From this position, slowly bend your hips and pull your knees upwards while continuing to keep your legs together until you reach approximately a 125 degree bend in your hips and knees. Pause in the up position for one second before slowly moving the knees back down to the starting position.

One study (5) showed that power wheel roll-outs and hanging knee raises are superior to sit-ups. The scientists attached electrodes to the abdominal muscles of 21 volunteers to measure muscle activity during 12 different abdominal exercises including sit-ups, power wheel roll-outs and hanging knee raises. The data showed that power wheel roll-outs activated the upper and lower abdominal muscles the most, while hanging knee raises activated the inner and outer oblique abdominal muscles the most. Sit-ups performed quite poorly - they activated the abdominal muscles only half as much as power wheel roll-outs and the oblique abdominal muscles only half as much as hanging knee raises. Taken together, these results show that sit-ups are a poor choice for training the abdominal muscles, while power wheel roll-outs should be used, especially if you want to focus on developing the abdominal muscles. Use hanging knee raises to target the obliques more precisely.

Deadlifts activate the entire core

Although deadlifts are primarily known for their unrivaled capacity to build muscle mass and strength, they are also great for building core strength as they directly activate all the major muscle groups responsible for core strength. In fact, deadlifting improves core strength and development more effectively than many of today's popular core training techniques, including sit-ups.

The ability of the deadlift to potentially activate the entire core was demonstrated in a study by Hamlyn and colleagues (6), who examined the degree of activation of different core muscles during the performance of deadlifts and two well-known core exercises - the "Superman" exercise and the "side bridge". In this study, 16 subjects performed either deadlifts at 80 percent of their maximum weight for one repetition or one of the other two core exercises while the activity of their core muscles was measured. Since the "Superman" and "Side Bridge" exercises are better than sit-ups at activating the core muscles, deadlifts are also more effective than sit-ups when it comes to activating the core muscles. The upshot of this is that deadlifts are an often overlooked but obviously essential component of any exercise program for core development, whereas the use of sit-ups appears to be relatively ineffective when it comes to targeting the muscles of the core.

In summary, although many still use sit-ups to improve their abdominal muscle development and core performance, scientific research clearly shows that alternative training modalities such as power wheel roll outs and hanging knee raises along with deadlifts generate superior activation of the primary muscle groups of the core. The superior abilities of these different training modalities in terms of activating the muscle groups of the core promote superior training adaptations that increase core development and strength to a greater extent, ultimately leading to better performance in the weight room and the development of a highly coveted six-pack.

References:

1. Kibler WB, Press J and Sciascia A. The role of core stability in athletic function. Sports Med 2006; 36, 189 -198
2. McGill SM. Low back disorders: evidence based prevention and rehabilitation. Human Kinetics Publishers 2007.
3. Callaghan JP and McGill S.M. Intervertebral disk herniation: studies on a porcine model exposed to high repetitive flexion/extension motion with compressive force. Clin Biochem 2001 (Bristol, Avon); 16, 28 - 37
4. Tampier C, Drake JD, et al. Progressive disc herniation: an investigation of the mechanism using radiologic, histochemical and microscopic dissection techniques on a porcine model.
5. Escamilla RF, Babb E, et al. Electromyographic analysis of traditional and nontraditional abdominal exercises: implications for rehabilitation and training. Phys Ther 2006; 86, 656 - 671
6. Hamlyn N, Behm DG and Young W.B. Trunk muscle activation during dynamic weight-training exercises and isometric instability activities. J Strength Cond Res 2007; 21, 1108 - 1112