The Effect of Aerobic Exercise on Brain-Derived Neurotrophic Factor in People with Neurological Disorders: A Systematic Review and Meta-Analysis.

OBJECTIVE: To determine the effect of aerobic exercise on brain-derived neurotrophic factor (BDNF) levels in people with neurological disorders. DATA SOURCES: Six electronic databases (CINAHL, PubMed, Cochrane, PsycINFO, SportDiscus, and Web of Science) were searched until the end of December 2016. STUDY SELECTION: Experimental or observational studies of people with neurological disorders who undertook an exercise intervention with BDNF as an outcome measure. The search strategy yielded 984 articles. DATA EXTRACTION: Study data were independently extracted from each article. Methodological quality of studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. A meta-analysis was planned based on the assessment of predetermined criteria. DATA SYNTHESIS: Eleven articles were included. Studies employed either a program of aerobic exercise, a single bout of aerobic exercise, or both. A meta-analysis of studies comparing a program of aerobic exercise against usual care/nil therapy showed a large effect (SMD: 0.84, 95% CI 0.47-1.20, p < 0.001) in favour of aerobic exercise to increase levels of BDNF. Findings for a single bout of aerobic exercise were mixed. Quality of studies was low (PEDro average score 4.3/10). CONCLUSIONS: A program of aerobic exercise may contribute to increased levels of BDNF in neurological populations.

The acute effects of aerobic exercise on sensorimotor adaptation in chronic stroke.

BACKGROUND: Sensorimotor adaptation, or the capacity to adapt movement to changes in the moving body or environment, is a form of motor learning that is important for functional independence (e.g., regaining stability after slips or trips). Aerobic exercise can acutely improve many forms of motor learning in healthy adults. It is not known, however, whether acute aerobic exercise has similar positive effects on sensorimotor adaptation in stroke survivors as it does in healthy individuals. OBJECTIVE: The aim of this study was to determine whether acute aerobic exercise promotes sensorimotor adaptation in people post stroke. METHODS: A single-blinded crossover study. Participants attended two separate sessions, completing an aerobic exercise intervention in one session and a resting control condition in the other session. Sensorimotor adaptation was assessed before and after each session, as was brain derived neurotrophic factor. Twenty participants with chronic stroke completed treadmill exercise at moderate to high intensity for 30 minutes. RESULTS: Acute aerobic exercise in chronic stroke survivors significantly increased sensorimotor adaptation from pre to post treadmill intervention. The 30-minute treadmill intervention resulted in an averaged 2.99 ng/ml increase in BDNF levels (BDNF pre-treadmill = 22.31 + /-2.85 ng/ml, post-treadmill was = 25.31 + /-2.46 pg/ml; t(16) = 2.146, p = 0.048, cohen's d = 0.521, moderate effect size). CONCLUSIONS: These results indicate a potential role for aerobic exercise to promote the recovery of sensorimotor function in chronic stroke survivors.

The Immediate Effects of Acute Aerobic Exercise on Cognition in Healthy Older Adults: A Systematic Review.

BACKGROUND: Age-related cognitive decline is a worldwide challenge, highlighting the need for safe, effective interventions that benefit cognition in older adults. Harnessing the immediate and long-term pleiotropic effects of aerobic exercise is one approach that has gained increasing interest. OBJECTIVE: The aim of this review is to provide knowledge on the immediate effects of acute aerobic exercise on cognitive function of healthy older adults and to assess the methodological quality of studies investigating these effects. METHODS: A database search in PubMed, CINAHL, Cochrane Central Register of Controlled Trials, Embase, PsycINFO, Web of Science, ClinicalTrials.gov and Google Scholar was conducted using a systematic search strategy. RESULTS: Fifteen studies were identified and cognitive domains investigated included executive function and visual perception. Results from 14 of 15 studies showed that an acute bout of aerobic exercise can enhance at least one subsequent cognitive performance of healthy older adults when measured within 15 min post-exercise. CONCLUSION: The small number of studies available, the limited domains of cognition investigated, the great variability between research protocols, and the low overall quality rating limits the conclusions that can be drawn. More comprehensive randomised controlled trials are needed to address these limitations and verify the potential benefits of acute aerobic exercise.