Sweat rate and environmental factors in junior Laser class sailors

Introduction: Recent studies have reported differences in sweat rate (SR) in laser class (LC) sailors under extreme environmental conditions (EC). This study aimed to determine a ‘standard-like’ SR in junior Laser 4.7 sailors under ‘not-extreme’ weather conditions to achieve an adequate fluid replacement rate for training and racing sessions. Additionally, we analysed the hypothetical relationship between SR and certain environmental factors, not just considering them as independent variables, but also including them as a whole factor, usually known as ‘windchill’ (WCh). Material and method: Nine male elite junior Laser 4.7 class athletes were included in this descriptive study. They were monitored during the entire year of training and racing sessions, including national and international championships. Body mass changes as well as their food and fluid intake were measured for each sailor before and after sailing to estimate SR, absolute body mass change, and percentage body mass variation for all the sessions. Athletes were asked to maintain “ab libitum” fluid and food intake during the study. Environmental temperature, wind speed, and relative humidity were measured. Results: Significant differences (p = 0.012) were observed between training and racing sessions with respect to SR, 0.18 (±0.14) L.h−1 vs. 0.23 (± 0.12 L.h−1). Environmental temperature and WCh during racing showed an inverse relationship with SR. Discussion: This result suggests that increased fluid and food intake are required under cold weather conditions to maintain the ‘target’ weight during the competitions and improve performance.