Neurotrophic growth factor responses to lower body resistance training in older adults.

Resistance exercise is an efficacious stimulus for improving cognitive function in older adults, which may be mediated by the upregulation of blood-borne neurotrophic growth factors (NTFs) like brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1). However, the NTF response to resistance exercise and training in older adults is poorly understood. Therefore, the purpose of this study was to characterize the timing and magnitude of the NTF response following an acute bout of resistance exercise before and after 8 weeks of resistance training. Ten cognitively normal, older adults (ages 60-77 years, five men) were examined. The acute NTF response to resistance exercise was assessed via serum samples drawn at designated time points following exercise. This procedure was then repeated following 8 weeks of resistance training. BDNF increased immediately post-exercise (Δ9% pre-training, Δ11% post-training) then returned to resting levels while IGF-1 remained stable following resistance exercise before and after 8 weeks of resistance training. Basal levels of both NTFs were unaffected by the 8 week training period. We report a transient increase in serum BDNF following a bout of resistance exercise in older adults, which could have implications for the design of interventions seeking to maximize cognitive function in older adults.