Acute And Chronic Anti-inflammatory Responses During A Season Training in Young Swimmers

It is well established that prolonged intense exercise training suppresses aspects of immune function and a perturbation in balance between pro- and anti-inflammatory cytokines may induce chronic, low-level systemic inflammation. Although swimming exercise training is demanding, however it is not clear whether it can promote changes in inflammatory responses. PURPOSE: This study investigated the acute and chronic effects of a full season swimming training on serum interleukin (IL)-4 and IL-1 receptor antagonist (IL-1ra), both at rest and after a maximal exercise bout. METHODS: Twelve well-trained male swimmers (14.08±1.0 yrs) were recruited. Measurements were carried out at the beginning of the training season (T1) and pre- and post the 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 IL-1ra and IL-4 levels were measured by ELISA. Adjustment for exercise-induced plasma volume changes was performed before all data analyses. Two-way ANOVA with repeated measures was used for statistics. RESULTS: Significant pre-post testing differences for IL-1ra (p=0.000), but not for IL-4 (p>0.05), were found throughout the experimental period. Pre-post testing difference was greater at T5 for IL-1ra and at T1 for IL-4 (165.95±36.16 pg/ml and 0.06±0.04 pg/ml, respectively). Both IL-1ra and IL-4 had similar, no significant (p>0.05) pre-testing responses, exhibiting an increase from T1 to T2 (IL-1ra: 200.04±14.73 vs 250.76±73.56 pg/ml and IL-4: 0.08±0.02 vs, 0.11±0.03 pg/ml) and from T3 to T5 (IL-1ra: 171.15±11.85 vs 187.66±19.89 pg/ml, IL-4: 0.08±0.03 vs 0.9±0.3 pg/ml) and a decrease from T2 to T3 (IL-1ra: 250.76±73.56 vs 171.15±11.85 pg/ml, IL-4: 0.11±0.03 vs 0.08±0.03 pg/ml). Post-testing, IL-4 response exhibited a 59% decline from T1 to T4 (0.14±0.05 vs 0.08±0.03 pg/ml,) and a 157% increase from T4 to T5 (0.08±0.03 vs 0.13±0.03 pg/ml), however those responses failed to reach statistical significance throughout the experimental period (p>0.05). CONCLUSION: These findings indicate that long-term swimming training can affect the resting and acute (pre-post testing) anti-inflammatory profile in young swimmers.