Johns Hopkins University researchers have found that dopamine plays a role in whether people find exercise and activity easy or tiring. The results of the study were published in the journal. magazine npj Parkinson’s Disease.
The hormone dopamine has been associated with pleasure, motivation, and reward seeking. It also seems to play an important role in why exercise and other physical activities seem “easy” for some people and tiring for others.
Researchers recruited 19 adults with Parkinson’s disease. It is characterized by the loss of dopamine-producing cells in the brain over time. Participants were asked to perform the same physical task—squeezing a sensor-equipped arm—for two days four weeks apart.
One day, patients were asked to take standard daily synthetic drugs to produce dopamine. On the contrary, refuse them at least 12 hours before the test. Participants also had to share their post-exercise experiences and rate their fatigue.
When the participants took the drug, they rated the exercise as easier. It’s harder when it’s not accepted.
The results show that dopamine levels are a critical factor in helping people accurately gauge how much effort a physical task takes.
The study will help explain persistent fatigue in conditions like depression, as well as developing new ways to motivate exercise, according to the scientists.