Why exercise gives your brain a boost – it’s down to dopamine

Studies have found that when people have been exercising, their cognitive performance improves – and now researchers think they’ve found out why.

Research published in the Journal of Physiology has found that the hormone dopamine, which is released during exercise, is linked to faster reaction time. (Dopamine is sometimes known as the “happy” hormone, because it is linked to pleasure.)

The researchers say that the finding could lead to a new therapeutic pathway for cognitive health, because of dopamine’s significant role in several conditions including Parkinson’s disease, schizophrenia, ADHD, addiction, and depression.

They measured the release of dopamine in the brain using a sophisticated scanning device, known as a positron emission tomography (PET). It tracks the metabolic and biochemical activity of the cells in the body.

More dopamine means faster reaction time

The scans showed that when a participant cycled lying down in the machine, their brain increased the amount of dopamine released, and that this process was linked with improved reaction time.

One of the team of researchers, Dr Joe Costello of the University of Plymouth, said: “We know cardiovascular exercise improves cognitive performance, but the exact mechanisms behind this process have not been rigorously investigated in humans until now.

“Using novel brain imaging techniques, we were able to examine the role dopamine plays in boosting brain function during exercise, and the results are really promising. Our current study suggests the hormone is an important neuromodulator for improved reaction time.

“These findings support growing evidence that exercise prescription is a viable therapy for a host of health conditions across the lifespan.”

The study involved carrying out three experiments with 52 male participants. In the first, participants were asked to carry out cognitive tasks at rest and while cycling in the PET scanner, so the team could monitor the movement of dopamine in their brain.

The second used electrical muscle stimulation to test whether forced muscle movement to stimulate exercise would also improve cognitive performance. The final experiment combined both voluntary and involuntary exercise.

In the experiments where voluntary exercise was carried out, cognitive performance improved. This was not the case, however, when only forced electrical stimulation was used.

The lead researcher, Soichi Ando, associate professor in the health and sports science laboratory at the University of Electro-Communications in Japan, said: “We wanted to remove voluntary muscle movement for part of the study, to see if the process in which acute exercise improves cognitive performance is present during manufactured exercise. But our results indicate that the exercise has to be from the central signals of the brain, and not just the muscle itself.

“This suggests that when we tell our central command to move our body during a workout, that’s the process which helps the dopamine release in the brain.”

Riding a bike reduces depression risk

Another study has found that people who cycle to work are less likely to be prescribed antidepressants. Analysis by the University of Edinburgh of almost 380,000 people living in Scotland suggests commuting by bike reduces the risk of mental ill health.

Researchers combined data for 378,253 people aged 16-74 from the 2011 Scottish census with NHS prescription records for the following five years. The people surveyed lived and worked in Edinburgh or Glasgow, stayed within around one mile of a cycle path and did not have any prescriptions for mental health problems at the start of the study. 

The research, published in the International Journal of Epidemiology, found a 15% reduction in prescriptions for depression or anxiety amongst cycle commuters in the five years after 2011 compared with non-cyclists.

Professor Chris Dibben, who led the study, said: “Our finding that this economical and sustainable method of travelling to work also enhances mental health suggests that a policy of investing in cycle paths and encouraging active commuting is likely to have wide-ranging benefits.”