The situp is the traditional exercise used for strengthening abs while the ab roller purports to strengthen both the abs and core. There are pluses and minuses of each. Full situps place excessive stress on your lower back, according to Len Kravitz, PhD, of the University of New Mexico. Though, the ab roller may not strain your lower back, it doesn't dynamically contract your abdominal muscles says ExRx.net. However, the roller may be more effective than situps.
Knowing Your Abs
Your mid-section muscles consist of the rectus abdominus, commonly known as the abs, and the internal and external obliques. The rectus abdominus extends between your lower sternum and pubic bone, and the external obliques, which are also known as the love handles, are located on either side of the rectus abdominus. The internal obliques run beneath the external obliques. Your abs flex your spine, bringing your rib cage and pelvis together. Exercises that mimic this action effectively work your abs.
No waist flexion occurs when you use the ab roller and there is no flexing of your spine to draw your rib cage and pelvis together. According to ExRx.net, the ab roller primarily works your Iliopsoas or hip flexors while your abs and external obliques contract isometrically to stabilize your pelvis and waist.
The Lowdown on Situps
Full situps engage your hip flexors, which arches your lower back and increases risk of back pain. Effective situps involve raising your trunk approximately 30 to 45 degrees off the floor, according to Kravitz. Lift your shoulder blades off the floor while keeping your lower back firmly pressed into the floor. This involves flexing your spine and drawing your rib cage and pelvis together.
Evaluating Ab Exercises
A study conducted at the Biomechanics Lab of San Diego State University for the American Council on Exercise compared the effectiveness of 13 commonly practiced ab exercises. Using electromyography equipment to determine which exercises activated the most muscle fibers, the study ranked the ab roller ninth, which was two places above the traditional crunch, for strengthening the rectus abdominus. The traditional crunch dynamically contracts your abs. Yet, the ab roller, which only isometrically contracts your abs as stabilizers, activates more muscle fibers. This suggests the ab roller is more effective than situps.
The ACE study placed exercise ball crunches and vertical leg crunches among the five most effective exercises for the rectus abdominus. To do exercise ball crunches, lie on your back on an exercise ball with your feet flat on the floor. Place your arms across your chest, exhale and contract your abs as you raise your trunk about 45 degrees. To do vertical leg crunches, lie on the floor with both legs in the air. Place your hands on your temples, exhale and contract your abs as you raise your trunk about 45 degrees. Combine these exercises with the ab roller for an effective and varied ab workout.