You don’t need to run a marathon or sign up for CrossFit. Fifteen or twenty minutes of walking, a dance class, or even an active video game that gets you moving is enough for your brain to notice. That’s the conclusion of the most complete scientific review ever conducted on exercise and cognitive function, published in the British Journal of Sports Medicine.
The work, led by Ben Singh and a team of Australian researchers, isn’t a new study with its own patients. It’s something more ambitious: a review of reviews (what science calls an “umbrella review”) that pooled 133 already-published systematic reviews and meta-analyses, covering a total of 2,724 randomized clinical trials and 258,279 participants of all ages, from 6-year-old children to 89-year-old adults. It is, by far, the largest analysis ever done on this question.
Exercise improves overall cognition, memory and executive function, and the effect is real. All three outcomes were statistically significant: overall cognition improved with an effect size of 0.42, memory with 0.26, and executive functions (planning, impulse control, working memory) with 0.24. In statistical terms these are small-to-moderate effects, but they held firm even after excluding the lowest-quality reviews and correcting for publication bias, two checks that usually make weaker findings disappear.
These aren’t just observational studies, they’re controlled trials. This is key: the 2,724 included studies are randomized clinical trials, meaning they directly compare people who exercised against people who didn’t (or did something different). That allows researchers to talk about a causal relationship, not just a correlation along the lines of “people who exercise also tend to take better care of their brains for other reasons.” Even so, the authors themselves flag an important limitation: the methodological quality of many of the 133 original reviews was low, which doesn’t invalidate the finding but does call for caution when interpreting the exact size of the effect.
Intensity matters less than you’d think. One of the study’s most useful findings is that the cognitive benefit didn’t depend on whether exercise was low, moderate or high intensity, how many times a week it was done, or how long each session lasted. Effects were even slightly larger for low- or moderate-intensity interventions. For anyone without the time or desire to train hard, that’s good news: walking, dancing or practicing Tai Chi counts.
Active video games and mind-body disciplines stood out from the rest. When comparing exercise types, “exergames” (video games that require real physical movement, like dance or boxing titles) had the largest effect on overall cognition. Mind-body disciplines such as yoga, Tai Chi or Baduanjin stood out especially for improving memory. The most likely explanation isn’t just physical effort, but that these activities also demand memorizing sequences, making quick decisions, or sustaining attention, adding a cognitive component on top of the physical one.
Children and teens with ADHD got the biggest boost. Younger participants showed notably greater memory improvements than adults and older people. And within executive functions, the group that improved the most was people with attention-deficit/hyperactivity disorder (ADHD), with a considerably larger effect than in the general population.
You don’t even need to keep it up for months to notice it. Surprisingly, shorter interventions (one to three months) had a larger effect on overall cognition than those lasting beyond six months. The authors point to several possible explanations: dropout is higher in longer programs, the novelty of a new routine may play a role in the initial cognitive boost, and short studies tend to have less demanding control groups, which could also inflate the result. Either way, science doesn’t yet have a definitive answer for why this happens.
With more than a quarter of a million participants and nearly 2,800 trials behind it, the authors stress that the practical takeaway translates easily to everyday life: any kind of regular exercise, even if it’s gentle and even if it’s only kept up for a few weeks, is linked to real improvements in memory, focus and the ability to think clearly, at any age.
Source: Singh B, Bennett H, Miatke A, et al. “Effectiveness of exercise for improving cognition, memory and executive function: a systematic umbrella review and meta-meta-analysis.” British Journal of Sports Medicine, 2025. Open access (CC BY-NC). DOI: 10.1136/bjsports-2024-108589. PMID: 40049759 | PMCID: PMC12229068 | PROSPERO registration: CRD42023468991
