It’s widely known that exercise builds stronger muscles, but new research suggests that exercise also reshapes the brain in ways that improve endurance. Research published in Cell Press journal neuron They found that repeated exercise changes brain activity associated with the body’s ability to run farther and faster over time. These changes appear to help the heart and muscles adapt to training and become stronger.
“Many people feel sharper and more alert after exercise,” says corresponding author J. Nicholas Betley of the University of Pennsylvania. “So we wanted to understand what happens in the brain after exercise and how those changes influence the effects of exercise.”
Brain activity continues even after exercise
During the experiment, Betley and his team observed an increase in brain activity in mice after running on a treadmill. The strongest changes appeared in nerve cells in a region called the ventromedial hypothalamus (VMH), which helps regulate how the body manages energy, weight, and blood sugar levels.
The researchers tracked the activity of a specific set of VMH neurons known as steroidogenic factor 1 (SF1) neurons. These neurons became active while the mice ran and continued to fire for at least an hour after the exercise ended.
After two weeks of daily treadmill sessions, the mice showed a clear increase in endurance. They were able to run longer distances and maintain faster speeds before becoming exhausted. Brain scans also revealed that more SF1 neurons were active after training, and the activity levels were much higher than at the start of the study.
Key neurons associated with increased endurance
The scientists then tested what happens if they block SF1 neurons from communicating with other parts of the brain. Mice whose neuronal activity was blocked fatigued faster and were unable to gain endurance during the two-week training period.
The researchers were particularly surprised to find that blocking these neurons only after exercise was enough to stop endurance gains, even though the neurons were still functioning normally during training. This finding suggests that post-exercise brain activity may play an important role in helping the body adapt to training.
“When we lift weights, we think we’re just building muscle,” Betley says. “It turns out that exercise can strengthen your brain.”
Recovery through exercise and brain function
The exact biological process behind this effect is still unknown. However, Betley believes that the continued activity of SF1 neurons after exercise may improve how stored glucose is used and help the body recover more efficiently. Doing so may help your muscles, lungs, and heart adapt more quickly to increasingly difficult exercise.
Researchers hope this discovery will eventually lead to new ways to help older adults stay active and recover from strokes and injuries. This approach may also be useful for athletes looking to improve performance and recovery.
“This study opens the door to understanding how to get more benefits from exercise,” he says. “If we can shorten the schedule and help people see the effects sooner, that might encourage them to continue exercising.”
This research was supported by the University of Pennsylvania, the National Institutes of Health, the National Science Foundation, the National Research Foundation of Korea, the Rhode Island Institutional Development Award, the Rhode Island Foundation, and Providence College.
