Here’s The Proof That Exercise Helps Your Brain Perform Better

HAMBURG — A healthy mind lives in a healthy body — the connection is so obvious that it became a saying centuries ago. But for a long time, researchers were unsure about cause and effect.

“The question was always: Does the brain determine physical activity, or does physical activity shape the brain?” says Boris Cheval, assistant professor of neuropsychology at the University of Rennes in France. In other words, do people exercise more and therefore maintain healthier neurons for longer? Or do they have healthier neural networks, which in turn make them more active?

In 2023, Cheval and his Swiss colleagues were able to answer this question with certainty. Exercise improves cognitive performance. Their study analyzed data from two massive scientific databases, tracking hundreds of thousands of people over several years. In around 350,000 cases, they were able to link cognitive test results with recorded daily activities and genetic information.

“When we look at the sequence of events, we see clear evidence that physical activity enhances cognitive function,” Cheval says.

Yet these improvements have their limits. Just because someone exercises a lot does not mean they will suddenly win a Fields Medal. “If you have bad grades in math and start exercising, your grades won’t skyrocket overnight,” Cheval says. Nobody becomes a genius through exercise alone. “But regular physical activity helps the brain function better.”

The 10-to 40-minute window

This improved efficiency may bring a small but noticeable advantage when learning. Studies have shown that students and young adults perform better on academic tasks when they exercise while studying or shortly afterward. “The ideal window for cognitive performance after moderate to intense physical activity is between 10 and 40 minutes,” says Philipp Zimmer, head of the Sports Medicine Department at the Technical University of Dortmund in Germany.

One possible reason for this short-term boost is a metabolic byproduct of sugar breakdown that is produced during exercise: lactate. “Lactate is an essential energy source for nerve cells and glial cells in the central nervous system,” Zimmer says. “It is also one of the few energy carriers that can pass through the blood-brain barrier.”

This barrier protects the brain and spinal cord from pathogens and harmful substances by allowing only certain compounds to pass through. Lactate is one of them. “But exercise has to be intense enough. Only then do lactate levels rise,” Zimmer says. At least moderate exertion is required. Lactate is essentially self-produced brain fuel. A brisk bike ride before an exam or an intense workout can provide a short-term cognitive boost, but the effect wears off within half an hour.

Once activated, the muscle-brain axis helps nerve cells grow, heal and form new networks.

In addition to lactate, other substances carried to the brain during exercise are receiving increasing attention from researchers. One of the most promising is BDNF, which stands for brain-derived neurotrophic factor. “BDNF has a wide range of effects on the brain, including neurogenesis, the formation of new neurons, and synaptogenesis, the formation of new connections between these nerve cells,” Cheval says. BDNF plays a particularly important role in areas of the brain involved in abstract thinking and memory formation.

BDNF is released during physical activity. The body produces substances in the liver and muscles that cross the blood-brain barrier and trigger the release of BDNF. Researchers refer to this as the muscle-brain axis. Once activated, this axis helps nerve cells grow, heal and form new networks.

Physical exercise is one of the most effective non-drug strategies for maintaining brain health. Running, for example, helps keep the brain functioning well. But it takes routine. “To improve brain health and performance, you need moderate to intense exercise at least three times a week, for 20 to 30 minutes each session,” Cheval says. Light activities, like casual walking, are not enough.

The type of sport also plays a role. “Team sports or activities that require strategic thinking are particularly good. They create time and space pressure and force quick decision-making,” Cheval says. This puts additional demands on cognitive abilities.

Exercise shapes character

Beyond its hormonal effects, exercise also strengthens certain brain regions. The hypothalamus, which regulates emotions and hormones, benefits from physical activity, as does the prefrontal cortex, which plays a crucial role in memory and attention.

This becomes particularly evident in response inhibition — the ability to control impulses. “Response inhibition is one of the most important cognitive skills for leading a self-determined life,” Cheval says. This ability helps people regulate their actions and make deliberate choices. It is closely linked to activity in the prefrontal cortex, which is stimulated by exercise.

People who exercise regularly are more focused and less impulsive.

Yet response inhibition is strengthened in a way that may seem unexpected. A key factor is overcoming laziness. “From an evolutionary perspective, physical activity is not something we are naturally inclined to do,” Cheval says. “If living beings have the option to conserve energy, the brain is wired to take that option.”

In nature, animals do not work out for fun. Lions, squirrels or lizards do not do sit-ups or push-ups unless there is a direct survival benefit. Humans, however, must push past this natural tendency to conserve energy. By overcoming laziness, they reinforce their ability to resist impulses. “That is why exercise has a strong influence on response inhibition,” Cheval says.

This leads to a crucial benefit. “People who exercise regularly are more focused and less impulsive,” Cheval says. Exercise, therefore, helps shape personality and promotes more deliberate and thoughtful actions.

Athletes’ brains deteriorate more slowly

Perhaps the most significant effect of exercise on the brain is its ability to slow down cognitive decline. Over time, the brain’s gray matter shrinks. From the age of 35, the cerebral cortex loses around 0.2% of its mass each year. After the age of 60, this loss accelerates to 0.5% annually. These brain regions are responsible for attention, memory and personality. By the time people reach the age of 90, their brains typically weigh 11 to 14% less than they did in young adulthood. Athletes, however, experience less of this decline.

“People who exercise regularly have a lower risk of developing neurodegenerative diseases,” Zimmer says. “And if they do develop one, their cognitive decline tends to be slower and less severe.” One key reason is that exercise helps prevent chronic inflammation, which is a major contributor to brain disease.

Inflammation is a common feature of conditions like multiple sclerosis, Alzheimer’s, dementia and Parkinson’s disease. In multiple sclerosis, for example, the immune system attacks the protective sheaths around neurons. “When these sheaths degenerate, nerve signals slow down or stop entirely — just like a damaged electrical wire,” Zimmer says. As a result, brain regions struggle to communicate, impairing thought processes and motor function.

Exercise counters inflammation in multiple ways.

Chronic inflammation in the body also increases the risk of brain damage. One major cause is excess visceral fat, which accumulates around the organs and releases inflammatory messengers into the body. “Because these messengers are mobile, they can spread beyond fat tissue and contribute to systemic inflammation, which may eventually affect the brain,” Zimmer says. This process, called metaflammation, can be worsened by prolonged psychological stress. The longer it lasts, the greater the risk of brain damage.

Exercise counters inflammation in multiple ways. It helps reduce body fat, lowering inflammatory signals. It also builds resilience. “Exercise creates temporary inflammatory stress, but the immune system adapts by increasing its anti-inflammatory capacity,” says Zimmer. Over time, this makes the body more resistant to chronic inflammation.

Regular physical activity, especially structured exercise, helps prevent conditions like dementia and multiple sclerosis. Even when these diseases develop, exercise can slow their progression. Zimmer particularly recommends endurance training. “The data suggests it is much more effective for brain health than strength training.” Team and competitive sports also show positive effects.

In the end, the most important thing is to move. “Even 75 minutes of exercise per week can make a difference,” Zimmer says. “But it has to be intense.”