Fast Walkers May Escape the Cognitive Toll of Aging, Dementia Risk Study Finds

Walking speed might seem like a mundane measure of fitness, but a new study suggests it could reveal who is most vulnerable to the cognitive erosion of aging. In an analysis of 920 older adults at elevated risk of dementia, researchers found that physical performance—how fast people walk, how hard they can grip, and how powerfully their legs can push—changes the strength of the link between age and executive function, the suite of mental skills that governs planning, self-control and the ability to switch between tasks. The findings, drawn from baseline data of the CITA GO-ON trial in Spain’s Basque Country, were published in the Journal of Cachexia, Sarcopenia and Muscle.

The stakes are enormous. Dementia currently affects roughly 50 million people worldwide, and projections suggest that number could nearly triple by 2050, reaching around 150 million. Alzheimer’s disease and vascular dementia account for the vast majority of cases, and in 30 to 40 percent of patients the two pathologies coexist. While new pharmacological therapies for early Alzheimer’s disease have generated excitement, they remain insufficient to slow the epidemic at a population level. The 2024 Lancet Commission on dementia prevention estimated that up to 45 percent of cases could be prevented by addressing 14 modifiable risk factors spanning early life, midlife and late life—among them hypertension, obesity, physical inactivity and social isolation.

Executive function is among the cognitive domains most sensitive to aging. Early losses in planning, inhibition and cognitive flexibility interfere with instrumental activities of daily living, reduce social participation and elevate dementia risk. Physical inactivity feeds this process through obesity, diabetes, dyslipidaemia and hypertension, but it also appears to act more directly: activity levels are consistently linked to executive performance over time. Objective markers such as gait speed, handgrip strength and leg muscle power integrate neuromuscular capacity, cardiometabolic health and central motor control into a single measurable phenotype, and previous research has tied them to independence, disability and dementia onset years before diagnosis.

What no study had done before, however, was test whether physical performance moderates—that is, changes the strength of—the relationship between age and executive function, rather than merely correlating with it. The research team, working with community-dwelling adults aged 60 to 85 recruited through town halls, mailings and media campaigns in Donostia/San Sebastián, enrolled participants with a high cardiovascular dementia risk score and subtle cognitive weaknesses, but without dementia or loss of functional independence. Only 6.8 percent of the sample met criteria for mild cognitive impairment, making the cohort a window into the preclinical stage of decline.

Executive function was measured with two well-validated instruments. The Trail Making Test asks participants to connect numbered circles and then to alternate between numbers and letters; subtracting the time for the simpler part from the harder part isolates the executive demands of task-switching. The Stroop test, in which people must name the ink colour of mismatched colour words, probes inhibitory control independently of literacy. Physical performance was assessed with a six-metre walk at usual pace, a handheld dynamometer measuring maximal grip force, and a leg press fitted with a linear encoder that captured peak lower-limb power during explosive contractions. Brain scans graded white matter hyperintensities—the hallmark of cerebral small vessel disease—on the Fazekas scale.

The results were striking in their consistency. After adjusting for sex, socioeconomic status, depressive symptoms, body mass index, anxiety, diabetes, hypertension, dyslipidaemia and smoking, all six age-by-performance interactions remained significant after false-discovery-rate correction. Each year of age added roughly 2.6 to 3.0 seconds to the Trail Making difference score and about half a second to Stroop interference, but higher physical performance blunted these penalties. Standardized interaction coefficients were modest yet reliable across both cognitive tests, and the pattern held whether the outcome was task-switching speed or inhibitory control.

The most novel contribution came from Johnson–Neyman analyses, which pinpoint the exact values of a moderator at which an effect disappears. For the whole sample, the damaging association between age and executive function became statistically undetectable above a gait speed of 1.83 metres per second, a handgrip strength of 48.8 kilograms, or a peak leg power of 438 watts on the Trail Making measure—and above 1.68 metres per second, 43.9 kilograms and 366 watts on the Stroop measure. These thresholds sit at the extreme upper end of the performance distribution: only about 1 to 16 percent of participants reached them, depending on the marker and test. The authors caution that these are sample-specific regions of significance, not clinical cutoffs ready for the doctor’s office.

Sex shaped the picture in intriguing ways. For the Trail Making test, the moderating effect of gait speed was confined to men, and a formal three-way interaction confirmed the specificity: among males, the age-related penalty on executive performance vanished above a gait speed of 1.59 metres per second, a level achieved by 14 percent of the men. For the Stroop task, gait speed moderated the association within the female stratum, but the corresponding three-way interaction was not significant, so the researchers urge against over-reading this as a true sex difference. Notably, when grip strength and leg power were re-expressed relative to body size, the moderation effects attenuated to nonsignificance, suggesting that absolute neuromuscular capacity—not strength adjusted for mass—drove the buffering effect.

Several sensitivity checks strengthened the findings. Excluding participants with mild cognitive impairment left most associations intact, indicating the pattern was not simply an artifact of incipient decline, though the gait effect on task-switching did weaken—hinting that gait speed may be an especially sensitive marker of executive problems in people already showing cognitive impairment. Adjusting for sleep quality or standing height changed little. White matter hyperintensity burden, present at moderate-to-high levels in nearly 29 percent of participants, did not independently predict executive function after full covariate adjustment, though the authors attribute this partly to the coarse visual Fazekas rating and the reduced MRI subsample of 774 people, and they stress this does not overturn the well-established links between small vessel disease and cognition.

Beyond the physical findings, socioeconomic status emerged as the second most powerful independent predictor of executive performance after age itself, with each step up the index corresponding to roughly 11 to 15 seconds of faster task-switching across both sexes—a vivid demonstration of cognitive reserve built through education, occupational complexity and access to healthier lifestyles. The study’s cross-sectional design cannot establish causality, and unmeasured factors such as medication use, habitual activity and APOE genotype may still confound the results. Yet the work offers a reproducible analytic template for the World Wide FINGERS network of multidomain prevention trials and raises a provocative possibility: that exceptionally high neuromuscular performance represents a functional reserve capable of buffering brain aging, complementing vascular-risk control. Whether those extreme performance levels can be reached through exercise interventions begun later in life—and whether doing so translates into real cognitive protection—remains the critical question for longitudinal research now underway.

Subject of Research: The moderating role of physical performance in the relationship between age and executive function in older adults at elevated risk of dementia

Article Title: Physical Performance Moderates the Association Between Age and Executive Function in Older Adults at Elevated Risk of Dementia: Cross‐Sectional Analysis From the CITA GO‐ON Trial

Article References: Reparaz‐Escudero, I., Izquierdo, M., Ecay‐Torres, M., Altuna, M., López, C., Estanga, A., García‐Sebastián, M., de Arriba, M., Ros, N., Saldias, J., Limousin, M., Martínez‐Lage, P., & Sáez de Asteasu, M. L. (2026). Physical Performance Moderates the Association Between Age and Executive Function in Older Adults at Elevated Risk of Dementia: Cross‐Sectional Analysis From the CITA GO‐ON Trial. Journal of Cachexia, Sarcopenia and Muscle, 17(5), Article e70396. https://doi.org/10.1002/jcsm.70396

Image Credits: AI Generated

DOI: 10.1002/jcsm.70396

Keywords: dementia, executive function, gait speed, handgrip strength, muscle power, aging, cognitive reserve, white matter hyperintensities, CITA GO-ON trial, sarcopenia, physical performance, dementia prevention