Exercise Can Actually Make Your Brain Look Younger, MRI Scans Reveal

Along with better sleep, healthier weight regulation, longer lifespan and a host of other physical and mental health gains, exercise may have another advantage: it could be associated with a more youthful brain profile.

Clinical trial findings on exercise and brain biological ageing

In a new 12‑month clinical trial involving 130 healthy adults aged 26 to 58, researchers in the United States reported that people who adhered to a comprehensive weekly exercise regimen finished the study with brains that appeared biologically younger than those of a control group.

When scientists refer to biological ageing, they are essentially describing the cumulative wear and tear that builds up as we get older. Although everyone adds one year to their age with each birthday, different organs and systems can age at different rates.

A “younger” brain could, in theory, mean maintaining full cognitive abilities for longer and having greater resilience to conditions such as dementia-although this study did not evaluate long‑term outcomes.

Following World Health Organization guidance: 150 minutes per week

Participants assigned to the exercise group were asked to meet the World Health Organization weekly recommendations: about 150 minutes of moderate-to-vigorous exercise-activity that noticeably increases heart rate and breathing.

Using a panel of biomarkers alongside MRI brain scans, the researchers found that the exercise group showed brains that looked, on average, 0.6 years younger than their chronological age.

By contrast, those who continued their usual routine had brains that appeared roughly 0.35 years older than their calendar age. The team noted that this latter estimate did not reach the threshold for statistical significance, but it places the gap between the two groups at close to a year overall.

What might explain a biologically younger brain?

The next issue is understanding why exercise might help keep the brain younger. Earlier research has associated exercise with improved brain function, and the new trial explored several plausible routes-including cardiovascular fitness, blood pressure and beneficial proteins.

However, the researchers said they were unable to identify a clear “missing link” connecting exercise with changes in brain ageing. They had anticipated that gains in fitness or reductions in blood pressure would explain the effect, but these measures did not account for it.

Instead, the team suggested that exercise could be working through other mechanisms not captured in their assessments, such as subtle shifts in brain structure, inflammation, vascular health, or additional molecular factors.

Why midlife exercise may matter

The researchers also highlighted that later‑life brain health is shaped by multiple influences that can act years earlier, and that exercise during midlife may produce measurable benefits.

A more youthful brain may be better placed to resist decline and disease, and it has also been associated with a longer life. These findings add to a growing body of evidence examining the key drivers of the brain ageing process.

Practical context: what “moderate-to-vigorous aerobic activity” looks like

In everyday terms, moderate-to-vigorous aerobic activity can include brisk walking, running, swimming, rowing, dancing, or cycling at a pace that makes conversation more difficult. The weekly 150 minutes can be accumulated across the week in manageable sessions, rather than needing to be completed in long workouts.

It is also sensible to build up gradually-particularly if you have been inactive-and to seek advice from a GP or appropriate clinician if you have a medical condition, are returning after illness, or experience symptoms such as chest pain or unusual breathlessness during activity.

What comes next

The team plans to investigate these potential pathways in future studies and wants to expand the work to larger, more diverse cohorts-potentially including people already considered at increased risk of cognitive decline.

Overall, the researchers argued that the results support the idea that meeting current exercise guidelines-150 minutes per week of moderate-to-vigorous aerobic activity-may help keep the brain biologically younger, even in midlife.

The study was published in the Journal of Sport and Health Science.