Effects of exercise intensity on salivary antimicrobial proteins and markers of stress in active men

• Published in: Journal of sports sciences 2008-04, Vol.26 (6), p.653-661
• Main Authors: Allgrove, Judith E., Gomes, Elisa, Hough, John, Gleeson, Michael
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; chromogranin A; Chromogranin A - metabolism; Cohort Studies; Exercise - physiology; exercise intensity; Exercise Test; Fundamental and applied biological sciences. Psychology; Humans; immunoglobulin A; Immunoglobulin A - metabolism; lysozyme; Male; Muramidase - metabolism; Saliva - chemistry; Saliva - metabolism; Saliva flow rate; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports
• ISSN: 0264-0414; 1466-447X
• DOI: 10.1080/02640410701716790

In the present study, we assessed the effects of exercise intensity on salivary immunoglobulin A (s-IgA) and salivary lysozyme (s-Lys) and examined how these responses were associated with salivary markers of adrenal activation. Using a randomized design, 10 healthy active men participated in three experimental cycling trials: 50% maximal oxygen uptake ([Vdot]O 2max ), 75%[Vdot]O 2max , and an incremental test to exhaustion. The durations of the trials were the same as for a preliminary incremental test to exhaustion (22.3 min, s x  = 0.8). Timed, unstimulated saliva samples were collected before exercise, immediately after exercise, and 1 h after exercise. In the incremental exhaustion trial, the secretion rates of both s-IgA and s-Lys were increased. An increase in s-Lys secretion rate was also observed at 75%[Vdot]O 2max . No significant changes in saliva flow rate were observed in any trial. Cycling at 75%[Vdot]O 2max and to exhaustion increased the secretion of α-amylase and chromogranin A immediately after exercise; higher cortisol values at 75%[Vdot]O 2max and in the incremental exhaustion trial compared with 50%[Vdot]O 2max were observed 1 h immediately after exercise only. These findings suggest that short-duration, high-intensity exercise increases the secretion rate of s-IgA and s-Lys despite no change in the saliva flow rate. These effects appear to be associated with changes in sympathetic activity and not the hypothalamic - pituitary - adrenal axis.