The effect of exercise on Parkinson's disease

What is Parkinson's disease?

Dopamine levels are reduced in the brain regions involved in movement (i.e. basal ganglia) because the nerve cells that naturally produce it slowly break down in people who have Parkinson's disease. Due to too little dopamine, signals in the brain are not transmitted or are not transmitted properly. Other brain cells and substances in the brain also do not work. This causes the connections between the brain areas that control movement to work less well. Ultimately, this causes movement to become more difficult. It is still unclear why the brain cells that make dopamine die and what causes the disease, although we do know that in some cases it may be hereditary. This lack of these signals can manifest itself is very unpleasant symptoms such as:

• Trembling hands, legs, chin and/or tongue (tremor)
• Slow/sluggish movement (bradykinesia)
• Loss of balance during movement
• Muscle stiffness (rigidity)
• Loss of facial mimicry (mask face)
• Delayed action and thinking
• Sleep disorders
• Mood problems and depression
• Obstipation
• Forgetfulness

Often, people have been ill for some time without knowing it before clinical symptoms become apparent and a diagnosis is made. It is precisely at this early stage where lifestyle intervention strategies may be most effective. However, the above symptoms vary greatly between people with Parkinson's disease. Not every individual with Parkinson's is the same and therefore a personalized approach for patients is hugely important. Currently, there is no cure. However, symptoms can be somewhat suppressed with a drug called L-DOPA, which replenishes dopamine in the brain, and paramedical disciplines such as physiotherapy, exercise therapy, dietetics, speech therapy, occupational therapy and the Parkinson's nurse can make an important contribution to the quality of life in people with Parkinson's disease.

Why does exercise help?

More and more evidence suggests that sufficient exercise can help with Parkinson's disease. Not only is sufficient exercise associated with a reduced risk of developing the disease, exercise also helps if you already have Parkinson's disease. During animal research, it was found that exercise causes new connections to be made between nerve cells (neuroplasticity). These new connections allow nerve cells to communicate better with each other and make information transfer more efficient. This happens, for example, when you learn new things or store memories, but also when nerve cells break down or stop working properly, as is the case in Parkinson's disease. This is when we speak of adaptive neuroplasticity. The brain then tries in a roundabout way to ensure that it can always function and thus there is no loss of function. In addition, large clinical studies show that exercise can help stabilize the disease and this in turn improves quality of life.

Exercise is a very accessible intervention strategy, as the risk of complications is acceptably low and by doing exercise in a game form (i.e. exergaming = 'exercising' and 'gaming'), it is also fun and can be sustained. Technology ensures that people can exercise at home in a low-threshold way and that their activities can be monitored by, for example, a guiding physiotherapist or doctor.

Parkinson's disease and cycling

The researchers discuss that two large clinical studies that have used exercise as an intervention show that aerobic exercise in particular, alongside medication, can be a complementary method to stabilize the disease. Two major studies mentioned here are the Park-in-Shape and the Study in Parkinson's Disease of Exercise (SPARX) studies. Aerobic exercise is a low- or high-intensity method of exercise that engages aerobic (= oxygen-consuming) energy processes in the body. This is achieved, for example, by doing a series of light- to medium-intensity activities for an extended period of time, such as cycling with resistance. Preliminary data and brain scans from study participants, show that regular aerobic exercise can stabilize connections between brain regions in the basal ganglia. These findings are consistent with animal experimental research. The exact mechanism in humans has not yet been elucidated, but some hypotheses are discussed in the studies.

Other studies (such as the one by Marianne Tiihonen, Britta U. Westner, Markus Butz and Sarang S. Dalal) looked specifically at the effect of cycling on Parkinson's disease. The authors concluded that cycling had beneficial effects on patients' motor performance, to a lesser extent on cognitive performance, but that it generally improved the quality of life of patients with Parkinson's disease. Thus, Bike Labyrinth can be an ideal tool to make exercise not only possible but also fun for people with Parkinson's disease. Besides having positive effects, cycling is also a form of exercise that is still possible for many patients, despite tremor or freezing (research by Anke H Snijders, Mirjam van Kesteren, Bastiaan R. Bloem).