Changes in Stress and Appetite Responses in Male Power-Trained Athletes during Intensive Training Camp

An intensive consecutive high-volume training camp may induce appetite loss in athletes. Therefore, this study aimed to investigate the changes in stress and appetite responses in male power-trained athletes during an intensive training camp. The measurements at Day 2 and at the end of a 9-day intensive training camp (Camp1 and Camp2, respectively) were compared with those of the resting period (Rest) and the regular training period (Regular; n = 13). The stress state was assessed based on plasma cortisol level, salivary immunoglobulin A level, and a profile of mood states score. The sensation of appetite was assessed using visual analog scale scores, and fasting plasma acylated ghrelin, insulin, and glucose were measured. The cortisol concentrations were significantly higher at Camp2 (466.7 ± 60.7 nmol∙L-1) than at Rest (356.3 ± 100.9 nmol∙L-1; p = 0.002) or Regular (361.7 ± 111.4 nmol∙L-1; p = 0.003). Both prospective and actual food consumption significantly decreased at Camp2, and acylated ghrelin concentration was significantly lower at Camp1 (34.2 ± 8.0 pg∙mL-1) and Camp2 (32.0 ± 8.7 pg∙mL-1) than at Rest (47.2 ± 11.2 pg∙mL-1) or Regular (53.4 ± 12.6 pg∙mL-1). Furthermore, the change in acylated ghrelin level was negatively correlated with the change in cortisol concentration. This study's findings suggest that an early-phase physiological stress response may decrease the acylated ghrelin level in male power-trained athletes during an intensive training camp.