666 FO22 – Sex, training variables, chronic disease, and injury are risk factors associated with history of exercise-associated muscle cramping in 10 973 ultramarathon runners: safer study

Background The prevalence of exercise-associated muscle cramping (EAMC) among ultramarathon runners is high. While the Comrades is one of the most popular mass community-based participation ultramarathons (90km) globally, research on the risk factors of entrants' lifetime history (hEAMC) is scarce. Objective Investigate selected risk factors of hEAMC among the 2022 Comrades Marathon entrants. Design Retrospective, cross-sectional study. Setting 2022 90km Comrades Marathon (road running race). Participants 10973 consenting race entrants. The race rules stipulate that entrants must be 20 or older and run a qualifying marathon within a specified time. Risk factor assessment Entrants completed a pre-race questionnaire that included questions about the lifetime prevalence (%; 95%CI) and risk factors (demographics, training/racing variables, chronic disease, allergies, injury) for hEAMC. Chronic disease risk factors were summarised as a continuous score out of 10, i.e., composite disease score, and included cardiovascular disease CVD risk factors, history of CVD, CVD symptoms, respiratory, gastrointestinal, nervous system/psychiatric, kidney/bladder, metabolic/endocrine, hematological/immune disease, and cancer) Main Outcome Measures Prevalence of hEAMC. Results 1582 entrants reported a hEAMC in their lifetime (14.4%; 95%CI:13.8–15.1). There was a significantly higher prevalence of male (16.1%; 95%CI:15.3–16.9) than female (8.3%; 95%CI:7.3–9.5) entrants with hEAMC (PR=1.9; 95%CI:1.7–2.2, pConclusions Future research should investigate the causal relationship between the risk factors identified and hEAMC in ultramarathon runners. Findings from this study could assist in adequate planning for treating EAMC encounters during community-based mass participation events based on the profiles of entrants.