Sport-specific oxidative stress and post-exercise metabolic responses in elite athletes: a pilot comparative study of boxing, biathlon, and modern pentathlon

Abstract

Problem Statement. Oxidative stress biomarkers may provide insight into athletes’ adaptation to high training loads. However, findings across sport disciplines remain inconsistent. Accordingly, the submitted manuscript required substantial methodological, linguistic, statistical, and bibliographic revision to satisfy the Journal of Physical Education and Sport standards.Approach. This pilot comparative study included 36 highly qualified male athletes during the special preparatory phase of the annual training cycle: boxers (n = 12), biathletes (n = 12), and pentathletes (n = 12). Blood catalase (CAT) activity and malondialdehyde (MDA) concentration were measured at rest and following sport-specific control loads, while blood lactate was assessed at 1 and 5 min of recovery. The revised analysis used one-way ANOVA to compare the sports at each time point, Holm-adjusted pairwise tests, and Hedges’ g effect sizes.Purpose. To compare CAT, MDA, and short-term lactate recovery across three Olympic disciplines with distinct energetic profiles and to present the findings in a cautious, journalcompliant form enriched with current literature and a publication-ready summary figure.Results. CAT differed significantly among sports before exercise, F(2, 33) = 105.11, p < .001, eta2 = .864, and after exercise, F(2, 33) = 13.10, p < .001, eta2 = .442. Post-load CAT was higher in modern pentathletes than in boxers (pHolm < .001) and biathletes (pHolm < .001), whereas boxers and biathletes did not differ (p = .667). MDA differed markedly at rest, F(2, 33) = 475.61, p < .001, eta2 = .966, and after exercise, F(2, 33) = 506.84, p < .001, eta2 = .968; boxers had the highest concentrations and biathletes the lowest values at both time points. Lactate at 1 min and 5 min recovery did not differ significantly between sports (p = .302 and p = .260, respectively). Descriptively, biathletes showed the strongest CAT increase (+98.4%) and fastest lactate clearance (-6.05%), whereas boxers showed a CAT decrease (-8.2%) and the highest MDA concentrations.Conclusions. CAT and MDA appear useful for profiling sport-related oxidative stress responses, but the findings should be interpreted as exploratory because of the small sample and non-identical sport-specific exercise protocols. Larger studies with standardized external-load monitoring and repeated-measures modelling are needed.