Changes in Parameters of Oxidative Stress, Immunity, and Behavior in Endurance Athletes During a Preparation Period in Winter

Michalickova, D, Minic, R, Kotur-Stevuljevic, J, Andjelkovic, M, Dikic, N, Kostic-Vucicevic, M, Slanar, O, and Djordjevic, B. Changes in parameters of oxidative stress, immunity, and behavior in endurance athletes during a preparation period in winter.J Strength Cond Res34(10): 2965-2973, 2020-The current study monitored markers of immunological and oxidative status in 9 male elite endurance athletes: V?o(2)max: 68 +/- 11 ml center dot kg(-1)center dot min(-1), age: 24 +/- 2.5 years, and training loads: 128 +/- 21 metabolic equivalents-h center dot wk(-1)during a 3-month preparation period in winter (January-March). Self-rated state of moods evaluation (by Profile of Mood States questionnaire) was performed, and blood samples were collected at the beginning and end of the study. Spectrophotometric methods and enzyme-linked immunosorbent assay were used for parameters' determination. The level of concanavalin A (ConA)-stimulated interferon-gamma (IFN-gamma) from peripheral blood mononuclear cells (PBMCs) was increased (562 [147-852] vs. 1,097 [451-1842] pg center dot ml(-1),p= 0.013). Also, the level of transforming growth factor-1 (TGF-beta 1) in serum was elevated (2.5 [1.4-5.1] vs. 7.2 [4.9-8.2] ng center dot ml(-1),p= 0.015). There was no change in the level of peptidoglycan (PGN)-stimulated interleukin (IL)-10 from PBMCs. There were no significant changes in PBMCs proliferation/viability on stimulation with ConA and PGN during the study. No changes in superoxide dismutase, prooxidative-antioxidative balance, total oxidant status (TOS), and thiobarbituric acid reactive substances were observed along the study. Total antioxidant status (TAS) was increased (910 +/- 174 vs. 1,090 +/- 102 mu mol center dot L-1,p= 0.018), and activity of paraoxonase (PON1) was decreased (523 +/- 295 vs. 335 +/- 183 U center dot L-1,p= 0.003) at the end of the study. Advanced oxidation protein products were increased (25 +/- 7.9 vs. 42 +/- 7.6 mu mol center dot L-1,p= 0.011). The self-rated sense of vigor significantly declined (20 +/- 2.1 vs. 14 +/- 3.4,p= 0.045). In conclusion, 3 months of regular training in winter induced prominent changes in cytokines, biomarkers of oxidative stress, and antioxidative enzyme activity. These changes might increase susceptibility of athletes to disease and muscle damage and consequently lead to performance reduction.