Immune parameters, symptoms of upper respiratory tract infections, and training-load indicators in volleyball athletes.

BACKGROUND: The control of immunological alterations becomes important during in-season training, as a result of increased incidence of infectious diseases, and may assist in avoiding interruptions to training due to illness. OBJECTIVE: The aim of the present study was to evaluate 28 weeks of chronic immune modulations in female volleyball athletes. METHODS: The sample was composed of twelve athletes aged 19.47 ± 2.49 years, height 1.78 ± 0.08 cm, and body mass 66.77 ± 7.8 kg. Leukocytes, individual immune cell count, interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α plasma cytokines were measured during the competitive period. RESULTS: Results revealed that immune variables were correlated with symptoms of upper respiratory tract infections and training-load indicators, indicating a possible marker of immune status. There was a statistically significant increase in total leukocytes, neutrophils, and monocyte count, a decrease in lymphocytes, and an increase in upper respiratory tract infection symptoms, with no change in IL-2, IL-6, and TNF-α. Correlations between subjective levels of tiredness, total leukocyte count, and neutrophils with upper respiratory tract infection symptoms were observed. CONCLUSION: In conclusion, these correlations can represent important tools to access the immune status of an athlete during long training periods, preventing a possible immunosuppressive status.