Acute And Chronic Brain-Derived Neurotrophic Factor Responses During One Season Training In Young Swimmers

It has been demonstrated that Brain-Derived Neurotrophic Factor (BDNF) is a mediator of neuroprotective and neuroplastic processes, and that serum BDNF is representative of central concentrations as well. Interestingly, there is evidence that BDNF levels are elevated in response to exercise. PURPOSE: This study aimed at investigating the acute and chronic effects of a full season swimming training on serum BDNF, both at rest and after a maximal exercise bout in young athletes. METHODS: Twelve well-trained male swimmers (14.08±1.0 yrs) participated in the study. Measurements were carried out at the beginning of the training season (T1) as well as pre- and post- taper of each of the two competitive periods (i.e., T2, T3 for the first macrocycle, and T4, T5 for the second macrocycle, respectively). At each of the above time points, blood samples were collected pre- and 1 hour post a maximal, 400m swimming testing. Serum BDNF levels were measured by ELISA. Adjustment for exercise-induced plasma volume changes was performed before data analysis. Two-way ANOVA with repeated measures was used for statistics. RESULTS: A significant pre-post testing difference was observed at T2 (p=0.048). In addition, a main effect of time was found among the 5 time points (T1-T5; p=0.000). Moreover, both pre- and post- testing responses had a similar profile exhibiting a decline from T1 to T3 (pre: 23,412±2,504 pg/ml vs 3,433±669 pg/ml, post: 23,004±3,410 pg/ml vs 2,743±550 pg/ml) and from T4 to T5 (pre: 19,428±1,097 pg/ml vs 11,993±969 pg/ml, post: 22,111±1,455 pg/ml vs 12,838±1,763 pg/ml), and an increase from T3 to T4 (pre: 3,433±669 pg/ml vs 19,428±1,097 pg/ml, post: 2,743±550 pg/ml vs 22,111±1,455 pg/ml). CONCLUSIONS: To the authors’ best knowledge this is the first study examining the acute and chronic BDNF responses during one season training in young athletes. These findings indicate that long-term swimming training can affect the resting and acute (pre-post testing) circulating BDNF in young swimmers.