Fluid Balance, Carbohydrate Ingestion, and Body Temperature During Men's Stage-Race Cycling in Temperate Environmental Conditions

Purpose: To observe voluntary fluid and carbohydrate intakes and thermoregulatory characteristics of road cyclists during 2 multiday, multiple-stage races in temperate conditions. Methods: Ten internationally competitive male cyclists competed in 2 stage races (2009 Tour of Gippsland, T1, n = 5; 2010 Tour of Geelong, T2, n = 5) in temperate conditions (13.2-15.8 degrees C; 54-80% relative humidity). Body mass (BM) was recorded immediately before and after each stage. Peak gastrointestinal temperature (T-GI (peak)) was recorded throughout each stage. Cyclists recalled the types and volumes of fluid and food consumed throughout each stage. Results: Although fluid intake varied according to the race format, there were strong correlations between fluid intake and distance across all formats of racing, in both tours (r = .82, r = .92). Within a stage, the relationship between finishing time and fluid intake was trivial. Mean BM change over a stage was 1.3%, with losses >2% BM occurring on 5 out of 43 measured occasions and the fastest competitors incurring lower BM changes. Most subjects consumed carbohydrate at rates that met the new guidelines (30-60 g/h for 2-3 h, similar to 90 g/h for >3 h), based on event duration. There were consistent observations of T-GI (peak) > 39 degrees C during stages of T1 (67%) and T2 (73%) despite temperate environmental conditions. Conclusion: This study captured novel effects of high-intensity stage racing in temperate environmental conditions. In these conditions, cyclists were generally able to find opportunities to consume fluid and carbohydrate to meet current guidelines. We consistently observed high T-GI (peak) which merits further investigation.