Being fit in older age supports brain regions that help you reach for right words

Moderate exercise in older age shapes brain activity which can reduce the number of ‘tip of the tongue’ moments, as new research shows that higher cardiorespiratory fitness alters our brain’s ability to reach for the right word at the right time.

In a new study published in the journal Neurobiology of Aging, researchers used MRI scans to study the brains of 73 healthy adults aged 60–81, who also completed a gold-standard cardiorespiratory fitness test (VO₂ peak). While in the scanner, participants were asked to complete a language task: they were shown definitions and asked to retrieve the correct word. As expected, participants often experienced ‘tip-of-the-tongue’ states — when the meaning of a word is known, but for a moment the sounds of the word cannot be found.

Healthy older adult participants experienced tip-of-the-tongue states in about 1 in every 6 attempts on average, but interestingly, those people with higher fitness levels tended to show modified brain activity which was associated with noticeably fewer tip-of-the-tongue states.

Dr Foyzul Rahman from the University of Birmingham and lead author of the study said: “What surprised us most was how fitter older adults showed different patterns of brain activity during word-finding attempts — even though all participants were broadly healthy and of similar age. In particular, those with higher cardiorespiratory fitness appeared to make use of a language-related brain network more effectively when they experienced a tip-of-the-tongue moment.

“This is important because it suggests that fitness is linked to the brain's ability to compensate for age-related changes in language. It’s not just that fitter people had better overall health — their brains were behaving differently in the moment of a cognitive challenge, showing a measurable difference in how language is processed.”

The research team measured VO₂ peak, a recognised indicator of how well the heart, lungs, and muscles work together during exercise. This is typically improved by moderate to vigorous aerobic activity like brisk walking, jogging, swimming, cycling, or dancing.

While a VO₂ peak of around 40 ml/kg/min is common in healthy younger adults, for healthy older adults (aged 60+), a typical value is closer to 28 ml/kg/min. The participants who took part in this study had an average VO₂ peak of 27.55 ml/kg/min, which is in line with population norms for their age group.

VO₂ peak is one of the strongest predictors of long-term health outcomes. Studies have shown that every 1 ml/kg/min increase in VO₂ peak is associated with a 10–15% reduction in all-cause mortality risk. The benefits of improving fitness are not only linked to better brain function — they’re also strongly associated with lower risk of cardiovascular disease, diabetes, and early death.

Dr Katrien Segaert from the University of Birmingham and senior author of the study said: “For most people, that would mean aiming for around 150 minutes of moderate exercise per week, which aligns with NHS guidelines. Importantly, our participants weren’t athletes and many were just reasonably active.

“So the message is encouraging. You don’t have to run marathons to see potential brain benefits and regular movement that gets your heart rate up can make a meaningful difference. That said, while our findings are promising, they don’t show cause and effect. More research — particularly longitudinal and intervention studies — is needed to determine how exercise may influence the ageing brain”