Getting in shape may do more for the brain than previously thought.
Improving physical fitness can strengthen the brain’s chemical response to exercise
Researchers have discovered that improving fitness levels can train the brain to release greater amounts of a key protein linked to brain health after exercise. The findings suggest that becoming physically fitter may amplify the mental benefits of a workout.
The study, published in the journal Brain Research, examined how a protein called brain-derived neurotrophic factor (BDNF) responds to exercise.
Often described as a form of “fertiliser” for the brain, BDNF supports the growth of new neurons, strengthens connections between brain cells and plays a role in maintaining healthy neural metabolism.
Although exercise is known to increase BDNF levels, scientists have been unclear about how improvements in fitness influence this response.
To investigate, researchers led by Flaminia Ronca at University College London recruited sedentary adults and divided them into two groups. One group continued their usual routines, while the other undertook a 12-week aerobic training programme consisting of cycling sessions four times a week.
Participants attended laboratory assessments at the start, midway point and end of the programme. Researchers measured cardiovascular fitness and collected blood samples before and after intense exercise to analyse BDNF levels in both plasma and serum.
Volunteers also completed computer-based tests assessing memory, attention and impulse control while brain activity in the prefrontal cortex - the region responsible for decision-making and focus - was monitored.
After three months, the exercise group showed clear improvements in cardiovascular fitness. While baseline BDNF levels remained unchanged, participants released significantly higher levels of serum-based BDNF following intense exercise.
The increase closely tracked gains in aerobic capacity, suggesting that greater fitness enhances the brain’s biochemical response to physical exertion.
Ronca told Psy Post: “We’ve known for a while that exercise is good for our brain, but the mechanisms through which this occurs are still being disentangled. The most exciting finding from our study is that if we become fitter, our brains benefit even more from a single session of exercise.”