Salivary Immunoglobulin A Secretion Rate During Peak Period Conditioning Regimens in Triathletes

Matsumoto M, Satoh, K, Kushi, H, Hamuro, K, Sakurai, M, Saito, H, Tanaka, R, Saito, T, Kohda, N, and Hamada, K. Salivary immunoglobulin A secretion rate during peak period conditioning regimens in triathletes. J Strength Cond Res 35(5): 1389-1396, 2021-Triathletes often feel unwell during the conditioning period (peak period) leading up to a race. The aim of this study was to evaluate the factors relevant to the condition of athletes and their impact on mucosal immune responses and the salivary immunoglobulin A (IgA) secretion rate. This study recruited college student triathletes (33 men and 7 women) who participated in an Olympic distance race. For each subject, the salivary IgA rate was measured continuously for 1 month before the race (peak period). Data on physical activity during the peak period were calculated in metabolic equivalents, and the relationships between these factors and the salivary IgA secretion rate were evaluated. The average amount of physical activity was highest during the 2- to 3-week period before the race, at 744.7 ± 51.5 kcal expended per day. In subjects who, on average, expended more than 1,000 kcal·d-1 in physical activity between 12 and 14 days before the race, the salivary IgA secretion rate was significantly reduced compared with the value at 1 week before the race (p < 0.05). On the day before the race, a further reduction was observed (p < 0.1). The salivary IgA secretion rate was decreased by high-intensity exercise during the peak period in advance of a race; this was associated with a loss of optimal condition just before the race.