Reduced sensorimotor lactate concentration and improved sleep efficiency following resistance training in older adults.

As populations age worldwide, pathological neurodegeneration with subsequent cognitive decline has emerged as a pressing public health challenge. As effective treatments remain limited once neurodegeneration has occurred, prevention and delay of decline onset are crucial. While physical exercise is associated with improved cognition, exercise-specific mechanisms remain unclear. We therefore examined the effects of 12 weeks explosive lower-body resistance training (RT) in community-dwelling older adults on proposed markers associated with brain metabolism and sleep. Thirty-six participants (64-81 years) completed pre and post assessments consisting of sensorimotor lactate and N-acetylaspartate (NAA) levels via 7 T magnetic resonance spectroscopy (analyzable lactate data: n = 24; NAA: n = 32), objective sleep architecture with wearable polysomnography (n = 34), and subjective sleep quality of the recorded nights with the revised sleep questionnaire A (n = 25) as well as of the preceding 4 weeks with the Pittsburgh Sleep Quality Index (n = 36). Participants were assigned to RT (3 sessions per week) or a control group (CON; maintaining lifestyle). After significant Group × Time interactions via repeated-measures ANCOVA with sex as covariate, paired t-tests revealed that RT significantly (p < 0.05) reduced resting lactate concentration (d = 0.78), improved objective sleep efficiency (d = 0.75), and prolonged total sleep time (d = 0.61). Our findings suggest that resistance training may be particularly beneficial for older adults experiencing fragmented sleep and impaired neural oxidative metabolism.