Physiology & Biochemistry 659 Sari-Sarraf V et al. Intermittent exercise, CHO in heat and salivary IgA … Int J Sports Med 2011; 32: 659–665 accepted after revision January 13, 2011 Bibliography DOI http://dx.doi.org/ 10.1055/s-0031-1271698 Int J Sports Med 2011; 32: 659–665 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0172-4622 Correspondence Dr. Vahid Sari-Sarraf, PhD Faculty of Physical Education and Sport Sciences University of Tabriz 22 Bahman BLVD Tabriz/Iran Tabriz 5166614776 Iran Islamic Republic of Iran Tel.: + 98/411/339 3254 Fax: + 98/411/356 008 vsarisarraf@yahoo.com Key words ● ▶ soccer-specific exercise ● ▶ salivary IgA ● ▶ cortisol ● ▶ CHO Effects of Carbohydrate Beverage Ingestion on the Salivary IgA Response to Intermittent Exercise in the Heat saliva flow rate and possibly salivary IgA secre- tion rate than when they perform the same exer- cise in thermoneutral conditions. Fluid ingestion can help to keep levels of oral pathogens low and temper the drying of the airways that occurs dur- ing exercise, thereby reducing the vulnerability of the upper respiratory mucosa to pathogens [2]. Laing et al. [29] showed that a prolonged bout of cycling in the heat evoked a reduction in salivary IgA secretion rate, but did not influence salivary IgA responses to prolonged exercise with ad libi- tum water intake. The addition of carbohydrate to solutions and the ingestion of fluids before and at regular intervals during prolonged and high-intensity intermit- tent exercise may extend exercise duration [3], but it may also attenuate perturbations in immune function [4, 17, 24] and decrease the potential for developing symptoms of respiratory tract infections [4]. Carbohydrate ingestion may also attenuate the rise in cortisol concentrations during exercise by maintaining plasma glucose concentrations [3]. Cortisol is known to inhibit transepithelial transport of salivary IgA [42], to inhibit in vivo B lymphocyte antibody synthesis Introduction ▼ Under normal environmental conditions, exer- cise-induced changes in immune response are relatively small and short-lived, limiting the “open-window” period when the likelihood of an acute infection might be increased [45]. Heat exposure is a form of stress in which elevations in body core temperature occur with concomitant alterations in hormonal and immune responses [9, 18, 39]. Exercise in a thermally stressful envi- ronment appears to have an additive effect on the hormonal and immune system disturbances compared to heat alone [31, 46, 54]. There is evidence of an acute increase in the syn- thesis of immunoglobulins after performing exercise under hot conditions [8]. Horswill et al. [28] suggested that exercise decreases salivary flow rate, which is further exacerbated by increases in ambient temperature. Regular fluid intake appears to prevent the exercise-induced decrease in flow rate [29]. Athletes performing prolonged exercise in the heat, with associated increased sympathetic activity and increased fluid losses, might exhibit larger reductions in Authors V. Sari-Sarraf 1 , D. A. Doran 2 , N. D. Clarke 3 , G. Atkinson 2 , T. Reilly 2 Affiliations 1 Faculty of Physical Education and Sport Sciences, University of Tabriz, Tabriz, Islamic Republic of Iran 2 Liverpool John Moores University, Research Institute of Sport and Exercise Sciences, Liverpool, United Kingdom 3 School of Human Sciences, Faculty of Life Sciences, London Metropolitan University, United Kingdom Abstract ▼ The purpose of this study was to establish if provision of CHO altered the mucosal immune and salivary cortisol responses to intermittent exercise in the heat. In a double-blind design, 10 males undertook soccer-specific intermittent exercise on a motorized treadmill on 2 occasions, each over 90 min and separated by 1 week. Dur- ing CHO and placebo trials, subjects were given either a carbohydrate solution (3 ml · kg − 1 body weight) or placebo drink, 5 min before the com- mencement of exercise, at 15, 30 min, at half time, 60 and 75 min into exercise. Salivary flow rate increased throughout the placebo trial and decreased throughout the CHO treatment; the difference between conditions neared statistical significance (P = 0.055). Neither s-IgA concentra- tion nor s-IgA to osmolality ratio was affected by 2 conditions or differed at any time-point post-exercise (P > 0.05). The s-IgA secretion rate increased, s-IgA to protein ratio decreased post- exercise and salivary cortisol decreased 24 h post-exercise (P < 0.05) compared to pre-exercise. Carbohydrate supplementation whilst exercising in the heat, does not influence rating of perceived exertion, thermal sensation, salivary flow rate, s- IgA concentration, s-IgA secretion rate, s-IgA to osmolality ratio or s-IgA to protein ratio and sali- vary cortisol but heart rate was increased.