A study by researchers at Johns Hopkins Medicine highlights the significant role of dopamine in how individuals perceive physical effort, particularly in those with Parkinson’s disease, where dopamine levels are deficient. Traditionally linked with pleasure and motivation, dopamine appears to influence the subjective experience of physical exertion, suggesting why tasks may feel easier for some and more challenging for others. Published in npj Parkinson’s Disease, the research could inform new strategies for promoting exercise and understanding fatigue linked to various conditions, including depression and long COVID.
Nineteen adults with Parkinson’s participated in the study, performing handgrip tasks under two conditions: after taking their usual dopamine medication and after abstaining from it. Results indicated that when participants were medicated, they assessed their effort more accurately and exhibited reduced variability in task performance. Conversely, without medication, they overestimated the effort required for the tasks.
The findings indicate that dopamine levels significantly affect motivation and decision-making regarding physical exertion, potentially aiding the design of treatments and interventions for exercise motivation and fatigue management across several clinical conditions.
