Cloud JA; The Ohio State University, Columbus, USA.
Howe IA; Kraemer WJ; Volek JS; Hayes JP; Hayes SM

Scientific Reports. 16(1), 2026 Mar 11.

Tasks associated with unilateral patterns of functional magnetic resonance
imaging (fMRI) activation often demonstrate bilateral activation with
aging (hemispheric asymmetry reduction). We examined relationships between
the modifiable lifestyle variable cardiorespiratory fitness (CRF),
hemispheric asymmetry reduction, and visuomotor task performance in
middle-aged and older adults. Sixty-four participants aged 35-86 years
completed progressive, maximal cardiopulmonary exercise testing to assess
VO2peak and a standardized test of motor coordination, the Grooved
Pegboard Test. fMRI was acquired during a visuomotor task requiring a
right-hand motor response. The relationships between hemispheric asymmetry
during the fMRI task, CRF, and performance on simple (fMRI task) and
complex (Grooved Pegboard Test) motor tasks were examined. Age moderated
the relationship between CRF (VO2peak) and hemispheric asymmetry. Among
middle-aged adults, greater VO2peak was associated with more hemispheric
asymmetry; no association was observed in older adults. Age marginally
moderated the relationship between hemispheric asymmetry and Grooved
Pegboard performance. Among middle-aged adults, greater hemispheric
asymmetry was marginally associated with better performance; among older
adults, reduced asymmetry showed a trending association with better
performance. These findings highlight age-related differences in the
relationship between CRF, behavioral performance, and fMRI activation and
emphasize the importance of investigating brain function, cognition, and
age across the adult lifespan.