ULTRA ENDURANCE CYCLING: A FIELD STUDY OF HUMAN PERFORMANCE DURING A 12 HOUR MOUNTAIN BIKE RACE

Abstract

384 Six mountain bike racers, ranging from recreational to expert riders (4 males, 2 females), participated in a continuous 12-hour race. Subject hydration status was estimated from body weight, fluid consumption, and content of discarded clothing pre-race and post-race, as well as throughout the 12-hour event. Blood glucose concentrations were obtained pre- & post race and when possible during the race. Heart rate and RPE were obtained once per hour via radio communication. Ambient temperature, humidity, barometric pressure, and light were measured 1 hour pre-race and every hour during the race. Performance was determined by time per lap, average speed per lap, and total number of laps performed. Ambient temperature and humidity ranged from 46-87 F° and 66-87% respectively. Barometric pressure range from 731mmHg at 12 midnight to 738 mmHg at 12 noon. Most subjects performed at approximately 70% of age predicted maximum heart rate. Body weight tended to decrease over the 12-hour period and changes in blood glucose concentration and hematocrit were variable and inconsistent. Results of this study represent a novel effort to monitor the physiological and psychological changes throughout an ultra-endurance cycling race. (Table)Table