The Perils of Working Just One Core MuscleAlthough the special effects of the black and white TV series "Lost in Space" seem primitive by modern standards, the science fiction story of the adventures of the Robinson family, stowaway Dr. Smith, and a robot, named Robot, were a staple of Thursday night viewing in the 1960's.
In almost every episode, Robot would sense imminent danger and warn young Will Robinson, played by a 10-year-old Billy Mumy, flailing his arms up and down, a light flashing on his chest, and repeating "Danger, Will Robinson! Danger!" Then there would be an advertisement followed by closing credits, the danger to be resolved in the next episode.
It's a good thing Robot did not have abdominal muscles. If he had, he might have developed a very painful, tired back.
Abs and Back PainIn the 1990's, Australian exercise scientists recruited volunteers who had lower back pain to enter a study. The scientists asked the lower back sufferers to wave their arms up and down in the style of the Lost in Space robot to measure changes in abdominal muscles. They also recruited healthy people who did not have lower back pain for a control group.
Among the volunteers who did not have lower back pain, the scientists discovered that a muscle called the transversus abdominis tensed just a few milliseconds before the arms went up and down. In the volunteers who had lower back pain, the transversus abdominis did not flex before the arms.
In lower back pain sufferers, not only was the spine weak and wobbly, the abs did not hold it in place. Other muscles had to be activated to make lifting the arms possible, and even then, motion was slower and painful.
The Australian researchers concluded that teaching back pain patients how to do suck-in-the-gut exercises might just be what was needed to relieve lower back pain without medication. For some back patients, the exercises worked. For some back pain patients, they didn't.
Exercise trainers around the world, however, seized on the idea of developing the abs. Six-pack abs, in which the transversus abdominis is so powerful it holds down surrounding tissues like a belt tightened over the belly button became the mark of being in shape. But is having great abs really healthy?
Healthy People May Not Benefit from Six-Pack AbsIn 2010, an article in the British Journal of Sports Medicine questioned whether healthy people really need to do abs exercises. People who have lower back pain, the scientists argued, may need to strengthen abdominal muscles, but people who do not have lower back pain may not need stronger muscles.
And in 2011, Dr. Stuart McGill, a highly regarded expert in the biomechanics of the spine and a professor at the University of Waterloo in Ontario, began a one-person campaign against abs exercises that require hollowing out the stomach. All the core muscles, McGill says, are not abdominal.
Core Ideas About the Core MusclesThe function of the core muscles, according to Dr. McGill, is to allow the body to move up and down and to the right and left while the spine is held straight. The transversus abdominis plays an important role in the core, and it's a muscle that rewards exercise with a visible six-pack. It is just not the only core muscle.
Muscles, McGill says, have to be balanced to keep the spine straight. If exercisers only work out one muscle in the core, there will be an unbalanced load on the spine. McGill compares the spine to a flexible fishing rod surrounded by guy wires that hold it in place. If you pull on all the guy wires with the same amount of force, the spine bears an even load. If you pull just the "wires" closest to the spine, which is analogous to the results of focusing on the transversus abdominis, then the spine buckles.
Experiments in Dr. McGill's laboratory indicate that spine injury is inevitable when people do just the exercises that pull in the belly button or "suck up the gut." The amount of load the spine can bear when the arms are flexed is greatly reduced when exercisers focus exclusively on abdominal muscle strength.
So what muscles need to be exercised to keep a healthy back?
Core exercise should develop all of the muscles surrounding the spine, including but not limited to the abs. Here are the essentials for a core workout:
- No sit-ups. Dr. McGill says they place a devastating load on the disks of the spine.
- Side planks. Raise your upper body as you lie on your side.
- Bird dogs. Get down on all fours, and raise arms and legs on alternating sides.
And while McGill does not recommend sit-ups, he does recommend crunches. Lie down and bend one knee. Place your hands beneath the hollow of your back for support.
Gently lift just your Head and shoulders. Hold for a moment, preferably until you feel a slight release in the muscles in your back—less than a "pop," involving no pain. (Stop if the exercise causes back pain.) Then lie back down in a comfortable position and repeat. Only the first 25 or so repetitions of any of these exercises will actually do you any good, and it is neither necessary nor helpful to do these three exercises more often than three days a week.
Dr. McGill says he sees too many people who have six-pack abs and a ruined back. He is not alone. Doctors at the Department of Public Health and General Practice at the Norwegian University of Science and Technology in Trondheim report that they have found no relationship between the thickness of the abs muscle, or how tightly it can hold down a six-pack, with back pain.
The Norwegian doctors also report that their patients who exercise other core muscles in addition to their abs experience significantly greater pain relief, although the process of healing can take months or years. Core muscles so weak that they "slide" cause the greatest pain.