Intriguing new research at The Cleveland Clinic suggests that there may be a way to supplement a normal exercise routine, adding strength and tone to your muscles without getting out of your chair.
Mental contractions and resistance training
The study of "mental contractions"—the use of the mind to exercise muscles—is a brand new field of research investigating an age-old phenomenon: that the mind has power over the body and its muscles. "This belief has been the basis of meditation and all of the so-called martial arts," says Cleveland Clinic researcher Vinod Sahgal, MD, Chairman, Department of Rehabilitation Medicine and one of the investigators of the study.
Guang Yue, PhD, principal investigator of the study at the Cleveland Clinic Lerner Research Institute, and his colleagues have used sophisticated brain imaging technologies to study the phenomenon and have found preliminary evidence that muscles in the body can be toned and strengthened through mental exertion.
This concept admittedly runs counter to conventional "resistance training"—the foundation of most strength and conditioning programs, and what most people engage in when they go to the gym.
Conducting the research
In a soon to be published study, Dr. Yue and colleagues assigned 30 healthy volunteers to three separate groups. The first group practiced mental contractions of the muscles in their hand; a second group practiced mental contractions of muscles in the elbow, and a third group, serving as a control, practiced neither.
The researchers used Magnetic Resonance Imaging to map the areas of the brain that were activated when participants engaged in mental exertion, and an electroencephalograph (EEG) to measure what Dr. Sahgal calls "movement-related cortical potentials"—a measure of electrical brain wave activity triggered by the exertion of muscles.
Here is what they found:
- Mental contractions of muscles in the hand produced electrical activity in the brain, indicating that the muscles were being worked.
- Comparisons of strength in the hand using traditional resistance exercises before and after the study showed that participants who practiced mental contractions did gain strength.
- Strength in the hand was increased by 35 percent, while strength in the elbow and arm increased by 13 percent. The difference may be related to two factors, Dr. Yue explains. One is that the hand muscle trained was the one that moves the little finger sideways, which is seldom used during daily living and, therefore, may reserve more room for improvements. Secondly, hand muscles are more highly "represented" in the brain—meaning, basically, that the brain is wired to exert greater control over muscles that are further away from it, than those that are closer.
Since this study is preliminary, it requires corroboration by follow-up research. But the findings could one day have important therapeutic implications for the treatment of patients with stroke or brain injury, as well as for designing strengthening programs for frail or elderly persons unable to do conventional exercise.
The notion that muscles can be strengthened mentally draws on the concept of "neural plasticity"--a recent neurological finding revealing that the brain has remarkable powers of rejuvenation and adaptation, says Dr. Sahgal. It appears that the brain can be re-trained to perform the tasks of movement and muscle exertion even after relatively severe trauma.
Because the brain is so complex, researching neural plasticity is extraordinarily difficult. "However, advanced neuroimaging techniques will give us a new window through which to look at the brain and see how it effects movement after motor control is destroyed."
Not a replacement, but a supplement
Although healthy people can use mental contractions, it will never replace a regimen of daily vigorous exercise, including conventional resistance training. Combining mental and physical exercises, however, may produce the best results, says Dr. Yue. Adds Dr. Sahgal, "Mental contractions may offer many healthy people a way to exercise anywhere, while keeping their muscles toned and strong.