Effect of glutamine and protein supplementation on exercise-induced decreases in salivary IgA

Effect of glutamine and protein supplementation on exercise-induced decreases in salivary IgA. J Appl Physiol 91: 832–838, 2001.—Postexercise immune impairment has been linked to exercise-induced decrease in plasma glutamine concentration. This study examined the possibility of abol-ishing the exercise-induced decrease in salivary IgA through glutamine supplementation during and after intense exer-cise. Eleven athletes performed cycle ergometer exercise for 2 h at 75 % of maximal oxygen uptake on 3 separate days. Glutamine (a total of 17.5 g), protein (a total of 68.5 g/6.2 g protein-bound glutamine), and placebo supplements were given during and up to 2 h after exercise. Unstimulated, timed saliva samples were obtained before exercise and 20 min, 140 min, 4 h, and 22 h postexercise. The exercise protocol induced a decrease in salivary IgA (IgA concentra