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

There are limited data on risk factors associated with illness-related medical encounters (illME) in cycling events. The aim of this study was to determine risk factors associated with illME in mass community-based endurance cycling events.

This is a retrospective cross-sectional study in the Cape Town Cycle Tour (109 km), South Africa, with 102,251 race starters. All medical encounters for 3 yr were recorded by race medical doctors and nurses. illME were grouped into common illnesses by final diagnosis. A Poisson regression model was used to determine whether specific risk factors (age, sex, cycling speed, and average individual cyclist wet-bulb globe temperature [aiWBGT]) are associated with illME, serious and life-threatening or death ME, and specific common illME.

Independent risk factors associated with all illME 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 ME were older age (P = 0.007) and slower cycling speed (P = 0.016). Risk factors associated with specific common illME were fluid and electrolyte disorders (females, older age, and higher aiWBGT) and cardiovascular illness (older age).

Females, older age, slower cycling speed, and higher aiWBGT were associated with illME in endurance cycling. These data could be used to design and implement future prevention programs for illME in mass community-based endurance cycling events.