Immune and oxidative stress responses in well-trained athletes after single sessions of prolonged aerobic exercise

Sammanfattning

Background: The use of biomarkers in sports poses many challenges as individual biomarkers are not definitive for diagnosing broad physiological states of training adaption, performance or health. Physical exercise induces significant changes in various biological responses, particularly the immune system, by triggering acute stress response mechanisms and oxidative response. Finding reliable biomarkers that can provide information about an athletes’ stress and recovery status could provide an opportunity to optimize and individualize exercise capacity and stress tolerance. Methods: 12 well-trained athletes visited the lab on five occasions – a pre-test followed by four trials with low- versus moderate-intensity treadmill running and speed versus heart rate with blood and saliva sampling at pre-, post- and 45 minutes post-training. Saliva Flow Rate, sIgA concentration, sIgA secretion rate and cortisol was analyzed in saliva and FORT, FORD and OSI in blood. Results: Levels of saliva flow rate and sIgA secretion rate were significantly higher POST exercise than both PRE and after 45 minutes rest after exercise. In plasma was both FORT and FORD significantly higher at POST exercise than both PRE and after 45 minutes rest after exercise. Conclusion: sIgA concentration increases in saliva but less saliva is secreted, indicating a decrease in immune defence at the oral mucosa. The greater increase in antioxidant defence than oxidative response may be due to the upregulated antioxidant expression in well-trained athletes. This study indicated that immune- and stress response have no significant differences between the tested intensities.