Serum brain-derived neurotrophic factor response to aerobic exercise in multiple sclerosis

Brain-derived neurotrophic factor (BDNF) and insulin-like growth factor (IGF)-1, support brain health through protective, regenerative and adaptive neural processes. In this study, we investigated whether exercise and exercise training would alter circulating BDNF and IGF-1 in people with multiple sclerosis (MS) and matched controls. Twenty-two volunteers (MS (n = 11) and controls (n = 11)) matched in age, weight, body fatness and aerobic capacity (VO_2peak) completed the study. Subjects cycled at 60% of VO_2peak, three times per week for 8 weeks. Serum was analyzed for BDNF and IGF-1 at rest and BDNF after a standardized exercise bout at weeks 0, 4 and 8. Resting BDNF levels were lower in MS compared to controls at week 0 (p = 0.03) and only tended to be lower at week 8 (p = 0.07). BDNF increased at week 4 in MS subjects (p = 0.04) and returned to baseline at week 8. With acute exercise, BDNF decreased in both groups during the 3-hour post-exercise recovery period. Resting IGF-1 concentration was not significantly different between groups before or after training. Our study provides preliminary evidence that exercise may influence BDNF regulation in humans. Further research is needed to elucidate the impact of exercise on neurotrophin production, secretion and target tissue responses in humans.