Time-dependent comparison of serum BDNF responses following high-intensity interval exercise and moderate- and low-intensity continuous exercise in healthy young men.
Level 2 - randomized trial
Randomized crossover trial in healthy human volunteers
PubMed 41620464 · doi:10.1038/s41598-026-37728-z
What was done
Twelve healthy young men completed three exercise protocols in a randomized crossover design with 7-day washout periods: low-intensity continuous exercise (LICE), moderate-intensity continuous exercise (MICE), and high-intensity interval exercise (HIIE). Venous blood samples were collected at baseline, immediately post-exercise, and at 5, 15, 30, 45, and 60 minutes of recovery to assess serum BDNF and blood lactate, alongside continuous heart rate monitoring.
What was found
Serum BDNF was significantly higher following HIIE compared to both LICE and MICE across all time points (p < 0.001), with no significant difference observed between LICE and MICE (p > 0.05). Within the HIIE condition, BDNF peaked at 15 minutes post-exercise and returned to baseline levels by 60 minutes. The abstract reports p-values but omits absolute concentrations, baseline values, and effect sizes.
Why it matters
It characterizes the acute post-exercise kinetics of peripheral BDNF, demonstrating that high-intensity interval protocols produce a distinct, transient neurotrophic surge compared to continuous moderate or low-intensity exercise.
Limits
The study is limited by a very small sample size (n = 12) and an exclusively young, healthy male cohort, preventing generalization to females, older adults, or clinical populations. Absolute concentration numbers and effect sizes are absent from the abstract. Serum BDNF is a surrogate peripheral measure that does not directly measure central nervous system BDNF kinetics or cognitive endpoints.