Risk Factors for Illness-related Medical Encounters during Cycling: A Study in 102,251 Race Starters-SAFER XI.

PURPOSE There are limited data on risk factors associated with illness-related medical encounters (illMEs) in cycling events. The aim was to determine risk factors associated with illMEs in mass community-based endurance cycling events. METHODS A retrospective, cross-sectional study in the Cape Town Cycle Tour (109km), South Africa with 102251 race starters. All MEs for 3 years were recorded by race medical doctors and nurses. illMEs were grouped into common illnesses by final diagnosis. A Poisson regression model was used to determine if specific risk factors (age, sex, cycling speed, average individual cyclist WBGT - aiWBGT) are associated with illMEs, serious and life-threatening or death illMEs and specific common illMEs. RESULTS Independent risk factors associated with all illMEs during an endurance cycling event were slow cycling speed (p=0.009) and higher aiWBGT (p<0.001). Risk factors associated with serious and life-threatening or death illMEs were older age (p=0.007) and slower cycling speed (p=0.016). Risk factors associated with specific common illMEs were: fluid and electrolyte disorders (females, older age, higher aiWBGT) and cardiovascular illness (older age). CONCLUSION Females, older age, slower cycling speed and higher aiWBGT were associated with illMEs in endurance cycling. These data could be used to design and implement future prevention programmes for illMEs in mass community-based endurance cycling events.