Research suggests that resistance training could help to slow the progression of multiple sclerosis.
Researchers found that engaging in resistance training twice per week for 6 months was associated with reduced brain atrophy - that is, the loss of brain tissue - in patients with relapsing-remitting multiple sclerosis (RRMS), the most common form of multiple sclerosis (MS).
For some patients, resistance training was even associated with an increase in the volume of certain brain regions.
Study co-author Prof. Ulrik Dalgas, of the Department of Public Health at Aarhus University in Denmark, and colleagues say that their study is the first to suggest that physical activity can protect the nervous system against MS, rather than simply help to alleviate symptoms of the disease.
The researchers recently reported their findings in Multiple Sclerosis Journal.
MS is a disease in which the immune system mistakingly attacks the protective coating of nerve fibers, called myelin, in the central nervous system.
As a result, the nerve fibers may become damaged or destroyed. This disrupts nerve signaling between the brain and spinal cord and causes a variety of symptoms, including muscle weakness, loss of balance, and walking difficulties.
According to the National Multiple Sclerosis Society, it is estimated that around 2.3 million people across the globe are living with MS.
RRMS is the most common form of MS, wherein a patient experiences attacks of symptoms, followed by periods of recovery.
Exercise and brain atrophy
Past studies have indicated that physical activity can help to ease some of the symptoms of MS. A 2012 review, for example, concluded that exercise training "has beneficial effects on muscular strength, aerobic capacity, and ambulatory performance, and may improve fatigue, gait, balance, and quality of life in patients with MS."
For this latest study, Prof. Dalgas and colleagues sought to determine whether exercise may also have a positive effect on the brain of patients with MS - in particular, whether it could protect against brain atrophy.
Brain atrophy - defined as a reduction in the size of brain tissue and loss of neurons - is a characteristic of progressive MS.
To reach their findings, the researchers enrolled 35 patients who had been diagnosed with RRMS, all of whom were receiving medication for the condition.
A total of 18 patients were randomly allocated to engage in resistance training twice weekly for 6 months, while the remaining 17 patients went about their normal day-to-day activities.
'New and important knowledge'
Before and after the 6-month study period, the brain volume and cortical thickness of each patient were assessed using MRI.
The researchers found that patients who participated in resistance training demonstrated a reduction in brain atrophy, compared with those who did not take part in the training.
"Among persons with multiple sclerosis, the brain shrinks markedly faster than normal. Drugs can counter this development, but we saw a tendency that training further minimizes brain shrinkage in patients already receiving medication," explains Prof. Dalgas. "In addition, we saw that several smaller brain areas actually started to grow in response to training."
Prof. Dalgas notes that research has long suggested that physical activity may help to treat the symptoms of MS, but he notes that "this study provides the first indications that physical exercise may protect the nervous system against the disease."
"[...] the fact that physical training also seems to have a protective effect on the brain in people with multiple sclerosis is new and important knowledge."
Prof. Ulrik Dalgas
The researchers say that they are currently unable to explain why resistance training appears to reduce brain atrophy among patients with RRMS, but they plan to address this question with future research.
The hope is that further research may lead to resistance training being considered as an effective treatment for MS, though Prof. Dalgas says that replacing medication with such exercise is unrealistic.
"On the other hand, the study indicates that systematic physical training can be a far more important supplement during treatment than has so far been assumed," he adds. "This aspect needs to be thoroughly explored."
The team cautions that patients with MS should consult a medical professional before engaging in any form of exercise.