No long-term benefits from resistance training on brain grey matter volumes in active older adults at retirement age

Abstract

Background: Resistance training and other forms of physical exercise are commonly suggested to promote brain health, yet the relationship between resistance training and brain structure in aging is poorly understood. We examined the short- and long-term influence of one year of supervised resistance training at two different loadings on brain structure in aging. Methods: In the LISA (LIve active Successful Ageing) study, well-functioning older adults at retirement age (mean age: 66 ± 2 years) were randomized to one year of heavy resistance training (HRT), moderate intensity training (MIT), or a non-exercising control group (CON). Magnetic resonance imaging (MRI) of the brain was performed at baseline, 1-, 2-, and 4-years follow ups. Trajectories of total grey matter, hippocampus, dorsolateral prefrontal cortex (dlPFC), ventrolateral prefrontal cortex (vlPFC), and white matter hyperintensities were analyzed in relation to changes in muscle strength. Results: Individuals (n = 276) with MRI scans at all 4 timepoints were included (HRT, n = 96; MIT, n = 95; CON, n = 85). Total grey matter volume decreased with time across all groups (F3,819 = 231.549, p < 0.001, η2 = 0.46), as did hippocampal (F3,819 = 310.07, p < 0.001, η2 = 0.53), vlPFC (F3,818 = 74.380, p < 0.001, η2 = 0.21), and dlPFC (F3,818 = 3.640, p = 0.013, η2 = 0.01) volumes. White matter hyperintensity volumes increased (F3,819 = 101.876, p < 0.001, η2 = 0.27). There were no significant group x time interactions for any of the brain structures. Additional cortical and subcortical vertex-wise analyses showed no group differences. Change in isometric leg strength was weakly associated with change in white matter hyperintensity volume across all individuals (r2 = 0.01, p = 0.048). Conclusions: One year of resistance training in well-functioning older adults at retirement age did not influence volume changes in selected brain regions over a 4-year period. Trial registration: The study was approved by the regional ethics committee and registered on clinicaltrials.gov 2014–04-24 (NCT02123641).