Immune function and exercise

This review will examine the effects of exercise and training on immune func-tion and will discuss the methodological problems that limit the interpretation of many exercise immunology studies. Acute bouts of exercise cause a tempo-rary depression of various aspects of immune function, such as neutrophil oxidative burst, lymphocyte proliferation, monocyte MHC class II expression, and natural killer cell cytotoxic activity, that will usually last for approximately three to 24 hours after exercise, depending on the intensity and duration of the exercise bout. Post-exercise immune function depression is most pronounced when the exercise is continuous, prolonged (<1.5 hours), of moderate to high intensity (55-75% VO₂max), and performed without food intake. Periods of intensified training that result in overreaching have been shown to chronically depress immune function—i.e., immune cell functions measured at rest are still depressed 24 hours after the last exercise bout. Although elite athletes are not clinically immune deficient, it is possible that the combined effects of small changes in several immune parameters may compromise resistance to common minor illnesses such as upper respiratory tract infection. Protracted immune depression linked with prolonged training may determine susceptibility to infection, particularly at times of major competitions.     

Mucosal immunity and upper respiratory tract infections during a 24-week competitive season in young ice hockey players

The aim of this study was to examine upper respiratory tract infections (URTI) and their associations with resting saliva and blood immune and endocrine parameters in ice hockey players. Twenty-seven participants (age 16.5 ± 0.5 years) completed the 24-week study period. The counts/concentrations of immune and endocrine markers were compared between healthy-prone athletes (≤2 episodes of URTI during the study period) and illness-prone athletes (≥3 episodes of URTI) and between the URTI state (when athletes had infections) and the healthy state (the time without URTI). There were no differences in concentration/counts of saliva and blood immune and endocrine parameters between the illness-prone and illness-free athletes. Athletes had significantly lower sIgA, sIgA1 and sIgA2 concentrations (sIgA: 119.88 ± 66.88, 144.10 ± 75.0 µg/ml; sIgA1: 90.2 ± 40.64, 108.44 ± 29.8 U; sIgA2: 67.58 ± 30.1, 80.3 ± 25.61 U, respectively) and significantly higher WBC, neutrophil, monocyte and eosinophil count values and IL-1ra concentration at the time when they had symptoms of URTI than in the period without symptoms of infections. There were no differences in salivary cortisol concentration between the period of URTI symptoms and the period without URTI symptoms. In conclusion, we observed lower concentrations of salivary immunoglobulins and higher levels of blood immune parameters during URTI in athletes, which may confirm the suppression of mucosal immunity and initiation responses to pathogenic infections by innate immunity.     

急性运动对免疫细胞的影响

回顾了运动免疫学近几年的研究，着重讨论了急性运动对免疫细胞的影响。包括急性运动对淋巴细胞亚群的影响，淋巴细胞对有丝分裂原的增生反应，NK细胞及中性粒细胞数量和功能的变化，以及运动后白细胞转运可能的机制等。