It is well-known that exercise is good for physical and mental health, but less well-known that exercising also protects and repairs the structures of the brain. This review summarises animal and human studies which demonstrate how physical activity has a direct beneficial effect on brain structures and biological processes.
Animal studies have revealed that physical activity increases the production of new neurons, improves the wiring which connects different parts of the brain, reduces demyelination and promotes remyelination. Recent research in mice has also provided evidence that exercise may create an environment in the brain which is more favourable for the actions of the remyelinating drug clemastine. The authors propose the term "MedXercise" to describe the synergistic effect seen when physical activity is paired with medication.
Studies in people with MS have shown that exercise leads to improvements in the wiring within the brain, reduced brain volume loss, reduced lesion numbers, and reduced activity in brain areas which had been compensating for loss of function.
The reviewers conclude that data from animal models and from people with MS support the view that exercise improves brain and spinal cord structures and functions but acknowledge there is still much to learn.
In the past, it was felt that since many people with MS experienced fatigue and found their symptoms worsened when hot, it was best to avoid activities that could be seen as tiring.
Regular, moderate exercise is now known to be an important part of maintaining good health and wellbeing for people with MS, helping to reduce fatigue and improve mobility, cognition and mental health. Physical activity also reduces the risk of developing other conditions such as cardiovascular disease.
However, there is more to exercise than physical fitness; research is now uncovering the direct beneficial effects of exercise on the brain. This review summarises animal and human studies which demonstrate how physical activity can affect brain structures and repair processes in multiple sclerosis.
Lessons from animal studies
In animal models of multiple sclerosis, exercise, such as providing access to a running wheel, has been found to delay the onset or reduce the severity of the MS-like condition.
Physical activity increases the production of new neurons, improves the wiring which connects different parts of the brain, reduces demyelination and promotes remyelination.
Exercise achieves this by acting on a range of biological processes. It appears to increase the number and development of oligodendrocytes, cells in the brain and spinal cord which are responsible for producing the myelin coating of nerve cells. Exercise limits inflammation in brain tissues by decreasing damaging cells and brain chemical while at the same time increasing cells and brain chemicals which repair damage. The levels of several brain-protecting molecules, such as brain derived neurotrophic factor, are increased. Physical activity strengthens the blood-brain barrier, preventing harmful immune cells from crossing from the blood stream into brain tissues.
The reviewers highlight a recent study in mice with an MS-like condition. The study looked at combining effect of exercise with clemastine, a drug used to treat allergies such as hay fever. Clemastine has been found to encourage immature oligodendrocytes to develop into cells capable of making myelin. The study found that when given alone, both exercise and clemastine increased remyelination. But when the two were given together, remyelination was further enhanced; more nerve fibres survived and almost all were remyelinated. The authors suggest that exercise creates an environment in the brain which is more favourable for the actions of a remyelinating drug and propose the term “MedXercise” to describe this synergistic effect seen when physical activity is paired with medication.
Exercise and the brain in people with MS
The effects of exercise in people with MS have been investigated using MRI techniques. This has demonstrated improvements in the wiring within the brain, reduced brain volume loss, reduced lesion numbers, and reduced activity in other brain areas which had been compensating for loss of function. Exercise improves cognitive symptoms and increases blood levels of brain-protecting molecules. Studies have also demonstrated benefits of different types of physiotherapy on MRI measures of brain structure which suggest neuroprotection or even myelin repair.
The reviewers conclude that data from animal models and from people with MS support the view that exercise improves brain and spinal cord structures and functions. They acknowledge there is still much to learn:
- does age or disability level influence the potential benefits of exercise on the brain?
- what difference does the timing (for example after a relapse), intensity or type of exercise have on brain repair?
- how can people benefit from exercise without causing other problems such as heat sensitivity or pain?
- would a combination of exercise and remyelinating drug also have an enhanced effect on brain repair in people living with MS?
Lozinski BM, Yong VW.
Exercise and the brain in multiple sclerosis.
Multiple Sclerosis 2020 Oct 30:1352458520969099 [Epub ahead of print].
Watch Professor Yong's presentation of the research behind this review at the 2020 MS Connect Conference, organised by the MS Society of Canada.
More about exercising with MS
Exercise can be something energetic or something more leisurely. There is no right or wrong exercise. However, the nature of MS may mean that you have to be more aware of your limits. If you have concerns about doing certain activities, talk to a health professional (eg your neurologist, GP, MS nurse, physiotherapist or occupational therapist) beforehand. You have to learn to listen to your own body and to be honest with what it is telling you. As recovery time can be longer for someone with MS, be prepared to stop before your body tells you that you've reached your limit.
Find out more about how exercise can help people with MS, how to get started with exercise, and choosing the right exercise to suit different needs and abilities. You can follow along to exercise videos or build your own routines, and get tips and advice from other people with MS.
