학술논문
Influence of the Thermal Environment on Work Rate and Physiological Strain during a UCI World Tour Multistage Cycling Race
Document Type
Periodical
Author
Source
Medicine and Science in Sports and Exercise. January 1, 2023, Vol. 55 Issue 1, p32, 14 p.
Subject
Language
English
ISSN
0195-9131
Abstract
Byline: JULIEN D. PÈëRIARD, Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT, AUSTRALIA ; MATHEW G. WILSON; SAMUEL T. TEBECK; JAMES B. GILMORE; JAMIE STANLEY; OLIVIER GIRARD, School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, WA, AUSTRALIA Abstract PURPOSE: This study aimed to characterize the thermal and cardiovascular strain of professional cyclists during the 2019 Tour Down Under and determine the associations between thermal indices and power output, and physiological strain. METHODS: Gastrointestinal temperature ( Tgi ), heart rate (HR), and power output were recorded during the six stages (129-151.5 km) of the Tour Down Under in ëñ22 male participants. Thermal indices included dry-bulb, black-globe, wet-bulb, and wet-bulb-globe (WBGT) temperature; relative humidity (RH), Heat Index; Humidex; and universal thermal climate index. The heat stress index (HSI), which reflects human heat strain, was also calculated. RESULTS: Dry-bulb temperature was 23×C-37×C, and RH was 18%-72% (WBGT: 21×C-29×C). Mean Tgi was 38.2×C-38.5×C, and mean peak Tgi was 38.9×C-39.4×C, both highest values recorded during stage 3 (WBGT: 27×C). Peak individual Tgi was [greater than or equal] 40.0×C in three stages and [greater than or equal] 39.5×C in 14%-33% of cyclists in five stages. Mean HR was 131-147 bpm (68%-77% of peak), with the highest mean recorded in stage 3 ( P ëñ 0.005). Mean power output was 180-249 W, with the highest mean recorded during stage 4 ( P < 0.001; 21×C WBGT). The thermal indices most strongly correlated with power output were black-globe temperature ( r = -0.778), RH ( r = 0.768), universal thermal climate index ( r = -0.762), and WBGT ( r = -0.745; all P < 0.001). Mean Tgi was correlated with wet-bulb temperature ( r = 0.495), HSI ( r = 0.464), and Humidex ( r = 0.314; all P < 0.05), whereas mean HR was most strongly correlated with HSI ( r = 0.720), along with Tgi ( r = 0.599) and power output ( r = 0.539; all P < 0.05). CONCLUSIONS: Peak Tgi reached 40.0×C in some cyclists, although most remained