Physiological predictors of exercise-induced increases in circulating BDNF isoforms and net cerebral lactate exchange in healthy adults.
Level 4 - case-series / case-control
Uncontrolled repeated-measures physiological study in healthy adults
PubMed 42519538 · doi:10.3389/fphys.2026.1862716
What was done
Sixteen healthy, physically fit adults (mean age 31 ± 6 years) performed three 20-minute cycling bouts at 40%, 60%, and 80% of VO2 max, separated by 30-minute rest intervals. Blood samples taken before and after each intensity were analyzed to determine whether platelet count, lactate, cortisol, and noradrenaline predicted changes in forearm venous serum mature BDNF (mBDNF-S) and precursor proBDNF. Net cerebral lactate exchange (LAC-AV-B), fast-twitch muscle fiber cross-sectional area (fCSA%-II), and BDNF Val66Met genotype were also evaluated.
What was found
The abstract reports directional relationships without numerical effect sizes or confidence intervals: - Increases in noradrenaline and lactate were related to increases in mBDNF-S. - Increases in cortisol were related to increases in proBDNF. - Net cerebral lactate exchange was related only to increases in circulating lactate. - Changes in mBDNF-S were predicted by fast-twitch muscle fiber area (fCSA%-II), while proBDNF increases were not. - Exploratory analyses showed a possible pattern of higher proBDNF levels in Val66Val carriers and a trend toward greater increases in net cerebral lactate exchange in Val66Met carriers.
Why it matters
This study indicates that mature BDNF and proBDNF respond to distinct physiological drivers during exercise, potentially differentiating metabolic and catecholaminergic signaling from glucocorticoid-mediated pathways.
Limits
The sample size is very small (n = 16) and restricted to healthy, physically fit adults. The abstract provides no exact numerical values, correlation coefficients, or p-values, and genotype findings are exploratory.