Motivation to exercise

Exercise is known to have many benefits to people with and without Parkinsons. In Parkinsons it is known to improve slowness of movement, balance, mood, memory and quality of life. There is also some evidence that it might slow down the progression of the disease. So we know that exercise is good for people with Parkinsons, but we still aren't sure why.

One of the theories is that exercise might cause more dopamine to be released in the brain. Dopamine is the chemical that people with Parkinsons lack, and that is why giving medications which contain dopamine are an effective treatment for Parkinsons.

In this study from Canada they used a special scan and tracer to measure dopamine release in the brain before and after exercise in Parkinsons patients. They also compared how dopamine release differed between regular exercisers and more 'sedentary' participants.

They found that even before starting any exercise the regular exercisers had a higher level of dopamine in their caudate (the area of the brain associated with Parkinsons) than the sedentary participants. But when they looked at any differences in dopamine levels in other areas of the brain there was no difference between the two groups.

All the participants then had to cycle on an exercise bike for 30 minutes before they were re-scanned. The second scan found that both groups, as expected, had an increase in dopamine release in the brain. Interestingly the regular exercisers had a bigger increase in dopamine release in the brain, suggesting that regular exercisers get an even greater benefit from exercise.

This study could explain why people with Parkinsons notice that their symptoms improve with exercise. It is also possible that exercise could promote nerve cells to survive for longer. However the problem with this study is that it does not provide any evidence as to whether this is a cause or effect of exercise. In other words, does the exercise cause higher levels of dopamine in the brain or do the higher levels of dopamine in the brain make those Parkinsons patients more likely to exercise. Either way, whether you have Parkinsons or you don't, the evidence is overwhelming that moderate exercise is good for your whole body including your brain. So unless you have a compelling reason not to, its a good idea to get and hopefully stay active.

Mov Disord. 2018 Oct 30. doi: 10.1002/mds.27498. [Epub ahead of print]

Habitual exercisers versus sedentary subjects with Parkinson's Disease: Multimodal PET and fMRI study.

Sacheli MA¹, Murray DK^1,2, Vafai N³, Cherkasova MV¹, Dinelle K³, Shahinfard E¹, Neilson N¹, McKenzie J¹, Schulzer M¹, Appel-Cresswell S^1,2, McKeown MJ^1,2, Sossi V³, Jon Stoessl A^1,2.

Author information

Abstract

BACKGROUND:

The benefits of exercise in PD have been linked to enhanced dopamine (DA) transmission in the striatum.

OBJECTIVE:

To examine differences in DA release, reward signaling, and clinical features between habitual exercisers and sedentary subjects with PD.

METHODS:

Eight habitual exercisers and 9 sedentary subjects completed [¹¹ C]raclopride PET scans before and after stationary cycling to determine exercise-induced release of endogenous DA in the dorsal striatum. Additionally, functional MRI assessed ventral striatum activation during reward anticipation. All participants completed motor (UPDRS III; finger tapping; and timed-up-and-go) and nonmotor (Beck Depression Inventory; Starkstein Apathy Scale) assessments.

RESULTS:

[¹¹ C]Raclopride analysis before and after stationary cycling demonstrated greater DA release in the caudate nuclei of habitual exercisers compared to sedentary subjects (P < 0.05). Habitual exercisers revealed greater activation of ventral striatum during the functional MRI reward task (P < 0.05) and lower apathy (P < 0.05) and bradykinesia (P < 0.05) scores versus sedentary subjects.

CONCLUSIONS:

Habitual exercise is associated with preservation of motor and nonmotor function, possibly mediated by increased DA release. This study formulates a foundation for prospective, randomized controlled studies