A short session of physical activity may trigger waves of brain activity that help people retain and recall information more effectively, according to new research.

Memory lapses are a common frustration. Names, shopping lists or key facts for an exam can vanish moments after being learned, highlighting how unreliable recall can be in everyday life.

However, scientists say a simple solution may lie in movement. Even a few minutes on an exercise bike or a brisk walk could provide an immediate lift to memory when learning new material.

Studies have consistently shown that aerobic activity, often referred to as cardio, can enhance memory performance. Exercise has long been linked to improved cognitive function, boosting performance on mental tasks and reinforcing parts of the brain that are vulnerable to ageing, potentially delaying cognitive decline.

Researchers also point to the hippocampus, a region central to memory formation, as a key player. Physical activity has been shown to strengthen this area, with moderate exercise several times a week even increasing its size. Timing appears to matter as well. Some studies suggest that exercising several hours after learning improves retention more than exercising immediately afterward, while stretching alone does not appear to offer the same benefit.

Until recently, the biological mechanisms behind these effects were not fully understood. A new study sought to uncover what happens inside the brain following exercise.

Neuroscientists examined brain activity in 14 participants immediately after physical exertion. They observed brief bursts of electrical signals moving between neurons—signals believed to be critical for consolidating memories. Known as “brain ripples,” these synchronized patterns occur when groups of neurons fire together, explains Michelle Voss, a neuroscientist at the University of Iowa who led the research. Such activity is thought to play an essential role in organizing and storing memories during sleep and quiet rest. The participants all had drug-resistant epilepsy, but researchers focused only on healthy brain regions producing normal signals.

The team tracked how the brain responded after short periods of exercise. They found increased ripple activity not only in the hippocampus but also in connected brain regions. Scientists believe this heightened activity supports the process of memory consolidation. "These pulses were also more finely synchronised with neural activity in the rest of the brain," Voss says.

The study was made possible through collaboration with neurosurgeons monitoring patients undergoing evaluation for epilepsy surgery. Because these patients had electrodes temporarily implanted in their brains, researchers could directly measure electrical activity before and after exercise sessions on a stationary bike. Although participants were not asked to learn new information during the experiment, earlier research had already identified these ripples as a possible mechanism for strengthening memories.

"That presents us with a unique opportunity to understand how the human brain works with direct measurements of electrical signalling, which is the primary currency of how the brain works," Voss says. Because these ripples occur too quickly for standard brain scans to detect, the study offers rare direct evidence of how exercise influences brain activity.

According to Voss, this synchronization may explain why people often remember information better if they engage in physical activity soon after learning it. Notably, even brief periods of movement were enough to increase ripple activity, suggesting that short bursts of exercise can be beneficial.

Researchers say the findings could help reshape public health messaging, emphasizing the cognitive benefits of staying active, particularly as people age. Strengthening memory-related brain regions may offer protection against cognitive decline.

Beyond memory, exercise delivers a range of mental and physical benefits. Previous studies show that a single workout can sharpen focus for up to two hours and boost levels of dopamine, a hormone linked to feelings of well-being.

Another recent study found that higher fitness levels amplify these benefits. The more regularly people exercise, the greater the brain’s response to each workout.

This effect is linked to the body’s ability to produce Brain-Derived Neurotrophic Factor (BDNF), a protein essential for forming new neural connections. Individuals with greater cardiovascular fitness and muscle mass tend to produce more of it.

"There's a reason to stay active because you will benefit more every time," says Flaminia Ronca, an exercise physiology researcher at University College London in the UK, who led the study. "If you stick with exercise for six weeks, you will reap bigger benefits from any further sessions."