A comparison of the risk profile for developing illness-related medical encounters in half- and ultra-marathon runners

Abstract

Research comparing risk profiles for medical encounters in race entrants at distance running events is limited. The aim of this study was to determine and compare the risk profile for developing illness-related medical encounters in half-marathon compared to ultramarathon runners. Online pre-race medical screening questionnaire data from 76654 consenting race entrants (71.8% of all entrants) over four years of Two Ocean Marathon (2012-2015) were analysed, using a prospective cross-sectional observational study design. Study participants were classified in four risk categories (‘very high risk’, ‘high risk’, ‘intermediate risk’ and ‘low risk’) based on history of the following: existing cardiovascular disease (CVD), history of any symptoms of CVD, or any risk factor for CVD, disease in other organ systems, medication use and history of collapse in half-marathon and ultramarathon. We report the prevalence (%; 95%CI) in each risk category for half- and ultra-marathon entrants. When comparing the OR between the ultramarathon participants compared to the halfmarathon participants the OR was 43% (OR 1.43; CI 1.19-1.73) more for an ultramarathon participant to be categorised in the “very high” risk category compared to a half-marathon participant. The OR for an ultramarathon participant to be categorised in the “high” risk category was 28% (OR 1.28; CI 1.14-1.43) more compared to the half-marathon participant, whilst the OR for an ultramarathon participant to be categorised in the “intermediate” risk category was 83% (OR 1.83; CI 1.71-1.96) more compared to the half-marathon participants. This finding indicates a higher number of participants in the ultramarathon will compete with either/or existing CVD, symptoms of CVD, risk factors for CVD, diseases in other organ systems, prescription medication use, use of NSAIDs before/during a race, history of collapse compared to the half-marathon participants. This may suggest that the ultramarathon participants have a higher risk for sustaining a medical encounter during a race compared to the half-marathon participants during a half-marathon race.