In a recently published article, “Exercise as medicine in Parkinson’s disease”, written by Danish and Swedish authors, the authors argue that physical exercise should be regarded as a treatment method for Parkinson’s disease (PD) by preventing, alleviating and potentially even slowing the progression of the disease. The article concludes that physical activity should be included as a central part of PD treatment and suggests that exercise should be used early in the disease process together with medical treatment.
The authors argue that exercise has three different effects.
1. Primary prevention
Physical activity appears to reduce the risk of developing PD. Studies show that higher levels of moderate to vigorous physical activity correlate with a lower risk of developing PD, particularly in men. This protective effect is explained by the role of physical activity as a modifiable lifestyle factor, contributing to the maintenance of brain function and the reduction of inflammation and oxidative stress.
2. Secondary prevention
Here, exercise aims to slow the progression of the disease. In animal models, aerobic exercise has been shown to protect and rebuild dopaminergic nerve cells, which is central to PD. Although evidence from human studies is limited, research indicates that intensive aerobic exercise can improve motor symptoms and brain function in patients with early-stage PD. One study involving high-intensity exercise demonstrated stabilisation of motor symptoms as well as reduced brain atrophy. There are also a few interesting case reports supporting this, for example The Dopamine Dancer: The Value of Holistic Autotherapy in Parkinson’s Disease.
3. Tertiary prevention
Here, exercise is used as a symptomatic treatment to manage PD symptoms such as motor difficulties, balance problems and non-motor symptoms including sleep disturbances and depression. Studies show that several forms of exercise, including aerobic exercise, strength training and balance exercises, improve balance, gait and muscle strength, while also increasing quality of life.
Is there a scientific explanation for these effects? Can we identify biological factors that may produce these effects? According to the article, exercise is believed to stimulate neuroplastic changes, meaning the brain’s ability to reorganise itself, for example by increasing levels of nerve growth factors such as BDNF, brain-derived neurotrophic factor, which protects against dopaminergic cell death. Exercise may also support the brain’s plasticity through improved blood flow, reduced inflammation and improved mitochondrial function.
One of the most important molecular changes that occurs in the brain during exercise is the increase in growth factors, particularly BDNF and GDNF, glial cell line-derived neurotrophic factor. These hormones support the survival of dopaminergic neurons, nerve cells that produce dopamine, by promoting nerve cell growth and neuroplasticity. Since PD involves the loss of dopaminergic cells, exercise, through increased levels of BDNF and GDNF, may help maintain nerve cell function and thereby slow the progression of the disease. In rats, exercise has also been shown to reduce the brain’s content of alpha-synuclein. This result indicates that exercise helps the body clear alpha-synuclein from the brain; clumped alpha-synuclein forms harmful protein deposits.
So how much should one exercise, and what type of exercise is recommended? In general, a combination of aerobic exercise, strength training, and balance and gait training is recommended.
Here are some guidelines for each type:
Aerobic exercise
– Recommendation: 3–5 days per week.
– Intensity: Moderate to high intensity, corresponding to 60–80% of maximum heart rate.
– Duration: 20–60 minutes per session.
– Examples: Brisk walking, cycling or dancing.
– Purpose and effect: Aerobic exercise improves cardiovascular health, increases oxygen uptake and may improve motor symptoms as well as relieve non-motor symptoms such as fatigue and depression.
Strength training
– Recommendation: 2–3 days per week.
– Intensity: Moderate intensity, with the aim of performing 1–3 sets of 8–12 repetitions for each exercise.
– Examples: Training with free weights, machines or bodyweight exercises such as squats and push-ups.
– Purpose and effect: Strength training helps maintain muscle strength and mobility, which may improve balance and gait and reduce the risk of falls.
Balance and gait training
– Recommendation: 2–3 days per week, often combined with other forms of exercise.
– Examples: Balance exercises, such as standing on one leg, gait exercises, Tai Chi and yoga.
– Purpose and effect: These exercises improve postural stability, reduce walking difficulties and improve coordination, thereby lowering the risk of falls.
Other forms of exercise
Dance, boxing and certain martial arts have also shown positive effects on motor and non-motor symptoms in PD. These forms of exercise are often enjoyable and socially engaging, which can improve motivation and adherence to an exercise programme.
In summary, it is recommended to integrate several types of exercise each week. An exercise plan may include:
– 30 minutes of aerobic activity, such as cycling, three times a week
as well as
– Strength training focusing on large muscle groups twice a week
as well as
– Balance exercises and gait training twice a week.
Since PD is a variable disease with different degrees of severity, individual adaptation is recommended, preferably under the supervision of a physiotherapist or exercise specialist with knowledge of PD.
Unfortunately, one can conclude that it is not enough to take the dog for a walk now and then. Exercise that produces good effects in PD, and indeed for everyone else as well, is no walk in the park.