Heat exhaustion in The Sun‐Herald City to Surf fun run

Abstract
To investigate the relationship between motivational factors and physical and biological causes of heat exhaustion in fun run entrants. Case-control study, The Sun-Herald City to Surf fun runs in Sydney in 1991 and 1992. There were 63,732 race entrants who completed the run and received a finishing time; 79 runners with heat exhaustion and 310 age, sex and performance matched controls were enrolled in the study. A diagnosis of heat exhaustion was made if a runner collapsed and, when first receiving medical care, had a rectal temperature of 38 degrees C or higher. Two readily identifiable groups of runners were at high risk of heat exhaustion--accomplished non-élite (preferred) runners and runners of good ability (Group A). The attack rate was highest among accomplished non-élite runners, but a combination of a relatively high rate and the large number of entrants in Group A runners accounted for most cases. Four major risk factors for heat exhaustion were identified: motivation to exceed previous performance targets; failure to drink fluids during the run; failure of trained runners to acclimatise for the race by training in the warmer parts of the day; and previous history of heat exhaustion. Information from this investigation will enable more effective targeting of educational prevention programs in The Sun-Herald City to Surf fun run and provide baseline data for monitoring the effectiveness of these programs to modify high risk behaviour by participants.