Immediate effect of high-intensity exercise on brain-derived neurotrophic factor in healthy young adults: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized trials
PubMed 34481089 · doi:10.1016/j.jshs.2021.08.004
What was done
The authors systematically searched MEDLINE, Scopus, Cochrane CENTRAL, and SPORTDiscus through December 2020 for randomized and non-randomized studies examining pre-post changes in serum or plasma brain-derived neurotrophic factor (BDNF) after an acute bout of high-intensity exercise compared to a control condition. Pooled effect sizes and 95% confidence intervals were calculated for randomized controlled trials using a random-effects model.
What was found
The systematic review included 22 studies with 552 individuals (age range 20 to 31 years, 59.1% male), and 10 randomized controlled trials were included in the meta-analysis. High-intensity exercise showed higher BDNF levels compared to non-exercise (pooled effect size 0.55, 95% CI 0.12 to 0.98, I2 = 25.7%, 4 studies) and light-intensity exercise (pooled effect size 0.78, 95% CI 0.15 to 1.40, I2 = 52.4%, 3 studies). There was no statistically significant difference compared to moderate-intensity exercise (pooled effect size 0.93, 95% CI -0.16 to 2.02, I2 = 88.5%, 4 studies).
Why it matters
An acute session of high-intensity exercise stimulates an immediate rise in peripheral BDNF in young adults compared to rest or light activity. This suggests high-intensity bouts can serve as an efficient stimulus for circulating neurotrophic factors.
Limits
The meta-analyses for each comparison were based on very few trials (3 to 4 studies each). High heterogeneity was present in the moderate-intensity comparison (I2 = 88.5%). Findings are restricted to healthy young adults aged 20 to 31 years, and only immediate peripheral blood BDNF was measured rather than central levels or sustained cognitive outcomes.
Cited by
- supports Exercise increases brain-derived neurotrophic factor (BDNF), which stimulates the growth of new neurons in the brain.