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The Journal of Sports Medicine and Physical Fitness 2021 Apr 19

DOI: 10.23736/S0022-4707.21.12252-2


language: English

Risk factors for not finishing an ultramarathon: 4-year study in 23996 race starters, SAFER XXI

Nicola SEWRY 1, 2, Martin SCHWELLNUS 1, 2, 3 , Mats BORJESSON 4, 5, 6, Sonja SWANEVELDER 7, Esme JORDAAN 7, 8

1 Sport, Exercise Medicine and Lifestyle Institute (SEMLI), Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; 2 International Olympic Committee (IOC) Research Centre, Johannesburg, South Africa; 3 Sport and Exercise Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; 4 Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden; 5 Center for Health and Performance, Goteborg University, Göteborg, Sweden; 6 Sahlgrenska University Hospital/Östra, Region of Western Sweden, Göteborg, Sweden; 7 Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa; 8 Statistics and Population Studies Department, University of the Western Cape, Bellville, South Africa


BACKGROUND: Limited data support pre-race medical screening to identify risk factors for not finishing an endurance running race. The aim of the study was to determine risk factors associated with not finishing an ultramarathon.
METHODS: A prospective, cross-sectional study of Two Oceans ultramarathon (56km) race starters who completed a pre-race medical screening questionnaire. Race day environmental conditions were recorded on race day. Univariate analyses of risk factors associated with the did-not-finish (DNF) included race day factors and pre-race medical screening history.
RESULTS: Risk factors for DNF amongst 23996 starters during the 56km race included older age and being female (p<0.0001). After adjusting for age and sex, the following were significant univariate risk factors: fewer years of running (p<0.0001), less previous race experience (p<0.0001), less training / racing per week (p=0.0002), lower average weekly training distance (p=0.0016), slower race vs. training speed (p<0.0001), lack of allergies (p=0.0100) and average wet-bulb globe temperature (p<0.0001).
CONCLUSIONS: Females, older age, training-related factors (less training / racing, average weekly training distance, race vs. training speed) and average wet-bulb temperature, were risk factors for not finishing an ultramarathon. The results may not only assist runners and coaches in race preparation, but also have clinical implications for the medical planning prior to races.

KEY WORDS: Running; Endurance sports; Risk factors; Race performance; Pre-race screening; Medical screening; Adverse events; SAFER study

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