An analysis of decades of research on the cognitive effects of exercise suggests that even a single workout session can positively influence mental performance. The study, conducted by researchers at UC Santa Barbara and published in Communication psychologyfound that brief bouts of exercise have small but measurable impacts on cognitive tasks, particularly those requiring rapid reactions and mental flexibility. However, these effects vary depending on the type, intensity and timing of exercise, as well as the cognitive task performed.
While it is well established that regular exercise improves long-term physical health and brain function, the effects of single bouts of exercise remain less clear. The researchers sought to resolve discrepancies in previous findings, which alternately suggested that single workouts improve, hinder, or have no effect on cognitive performance. They aimed to identify consistent patterns in the relationship between intense exercise and mental processes, with a particular focus on cognitive domains such as attention, memory and executive function.
“Human cognitive neuroscience is a field dedicated to understanding the neural mechanisms of cognitive function and their links to behavior. The field is based on laboratory experiments in which participants engage in tasks whose performance we can closely control and measure. Sometimes we also perform measurements of brain activity using various neuroimaging methods,” said study author Barry Giesbrecht, professor and director of the Attention Lab at UC Santa Barbara.
“In my lab, we are very interested in how exercise and other changes in physiological state influence these processes. One of the most consistent findings in the literature is that exercise interventions (for example, something like a program you would participate in about 3 times a week for months) improve cognition and may even promote neurogenesis . Studies investigating the effects of single, acute bouts of exercise are much more mixed, largely due to variability in cognitive tasks and exercise protocol. Here, what we tried to do is get a sense of the most consistent patterns in the literature.
To assess the cognitive effects of intense exercise, the researchers conducted a meta-analysis of studies published between 1995 and 2023. They included experimental studies involving individuals aged 18 to 45, focusing on participants non-clinical and healthy. Eligible studies had to compare cognitive performance before and after exercise or between exercise and control conditions. The cognitive domains assessed ranged from executive function to attention, memory and motor skills.
The researchers conducted a meta-analysis synthesizing data from 113 studies (with 4,390 participants in total) published between 1995 and 2023 to assess the effects of a single exercise session on cognitive performance. Studies included in the analysis were selected based on specific criteria: They had to involve experimental designs in which participants performed cognitive tasks during or after an intense exercise session. Eligible studies included healthy adults aged 18 to 45 years.
To ensure a broad perspective, the meta-analysis included various types of exercise, such as cycling, running, high-intensity interval training (HIIT), resistance training, and sports activities. Exercise intensity ranged from light to vigorous, and duration varied across studies. The cognitive tasks tested participants’ performance in areas such as memory, attention, executive function, motor skills and decision-making. Reaction times and task accuracy were measured as primary indicators of cognitive performance.
The researchers used Bayesian statistical methods to analyze the data. This approach allowed for a more nuanced understanding of the evidence, incorporating probabilities and variability across studies. Unlike traditional statistical methods, Bayesian analysis estimates the probability of certain outcomes given observed data, making it particularly suitable for assessing the heterogeneous effects of exercise on cognition. Moderators such as exercise type, intensity, duration, and timing in relation to cognitive testing were included in the analysis to explore their influence on the results.
The meta-analysis found that a single exercise session had a small but significant positive effect on overall cognitive performance. Tasks targeting executive functions, such as inhibition and cognitive flexibility, were associated with the most consistent improvements. Attention and tasks requiring quick reaction times also showed measurable improvements. However, findings regarding memory and other cognitive domains were less consistent.
The researchers also identified important moderators. For example, the type of exercise played a crucial role, with cycling and high-intensity interval training (HIIT) showing the most substantial cognitive benefits, particularly for executive functions such as inhibition and planning. .
“With this particular finding, we have to be a little careful because there are a lot fewer HIIT studies in the literature, so with more studies this might change,” Giesbrecht said.
Exercise intensity also emerged as an important factor. Vigorous-intensity workouts produced the strongest cognitive improvements, while moderate-intensity exercises produced smaller but still noticeable benefits. These results suggest that the physiological and neurochemical changes induced by higher intensity exercise may be responsible for its greater impact on cognitive performance.
“We all know that regular exercise has positive effects on emotional and cognitive functions, in addition to general health improvements,” Giesbrecht told PsyPost. “Here we show that even a single session of intense exercise can have positive effects on cognition, particularly executive functioning.”
The researchers also observed substantial variability between studies, highlighting the importance of context in interpreting the effects of exercise on cognition. Factors such as cognitive task design, participant demographics, and experimental protocols all contributed to differences in results. For example, simpler cognitive tasks may have reached ceiling effects, limiting the ability to detect exercise-induced improvements. Additionally, variations in how exercise intensity and duration were reported across studies introduced additional complexity.
“Although consistent, the overall effect of a single exercise session was generally small,” Giesbrecht noted. “We think that an intriguing hypothesis that could explain this finding, besides the variability of the exercise protocols themselves, is that most studies show that people engage in a cognitive task during exercise or little of time after exercise. This is very different from the real world, which generally requires us to integrate the actions of our bodies and cognitive systems during our daily activities. We are about to embark on a series of studies that will systematically test this idea using a combination of laboratory tasks and real-world activities.
The article titled “A systematic review and Bayesian meta-analysis provides evidence for an effect of acute physical activity on cognition in young adults” was authored by Jordan Garrett, Carly Chak, Tom Bullock and Barry Giesbrecht .
