title: A prospective cohort study of 7031 distance runners shows that 1 in 13 report systemic symptoms of an acute illness in the 8-12 day period before a race, increasing their risk of not finishing the race 1.9 times for those runners who started the race: SAFER study IV.
abstract: BACKGROUND
  Data on the prevalence of acute illness in the period prior to a distance running race are limited. Currently, the presence of systemic symptoms (failed 'neck check') is used to advise athletes on participation.
  
  
  OBJECTIVE
  To determine (1) the period prevalence of pre-race acute illness symptoms before a distance running event, (2) if symptomatic runners receiving educational material on acute illness did not start (DNS) the race and (3) if symptomatic runners who chose to start the race, did not finish (DNF) the race.
  
  
  METHODS
  7031 runners completed an online pre-race acute illness questionnaire in the 3-5 day period prior to a race. Symptomatic runners received educational information on exercise and acute illness. Runners were followed prospectively to determine DNS and DNF risk.
  
  
  RESULTS
  1338 runners (19.0%) reporting symptoms (7.5% reporting systemic symptoms-failed 'neck check') and receiving educational information had a higher DNS frequency (11.0%) compared to controls (6.6%)(p=0.0002). Symptomatic runners who started the race had a higher DNF frequency (2.1%) compared to controls (1.3%) (p=0.0346), particularly runners with systemic symptoms (2.4%; RR=1.90).
  
  
  CONCLUSIONS
  In summary, 19% (1 in 5) runners reported pre-race acute illness symptoms, with 7.5% (1 in 13) reporting systemic symptoms. Although runner education reduced the percentage symptomatic race starters, the majority of them still chose to race, resulting in a two times higher risk of not finishing in those with systemic symptoms. Pre-race acute illness symptoms are common; an educational intervention affects an athlete's decision to compete yet most symptomatic runners still competed, and systemic symptoms negatively affect performance, with possible health implications.
authors.affiliation: UCT Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
authors.forename: Anri
authors.initials: A
authors.lastname: Van Tonder
authors.affiliation: Faculty of Health Sciences, Institute for Sport, Exercise Medicine and Lifestyle Research, Section Sports Medicine, University of Pretoria, Pretoria, South Africa International Olympic Committee (IOC) Research Centre, Pretoria, South Africa Emeritus Professor, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa.
authors.forename: Martin
authors.initials: M
authors.lastname: Schwellnus
authors.affiliation: Biostatistics Unit, South African Medical Research Council of South Africa, Tygerberg, South Africa.
authors.forename: Sonja
authors.initials: S
authors.lastname: Swanevelder
authors.affiliation: Biostatistics Unit, South African Medical Research Council of South Africa, Tygerberg, South Africa Statistics and Population Studies Department, University of the Western Cape, Cape Town, South Africa.
authors.forename: Esme
authors.initials: E
authors.lastname: Jordaan
authors.affiliation: International Olympic Committee (IOC) Research Centre, Pretoria, South Africa Faculty of Medicine and Health Sciences, Institute for Sport and Exercise Medicine, Stellenbosch University, Cape Town, South Africa.
authors.forename: Wayne
authors.initials: W
authors.lastname: Derman
authors.affiliation: Faculty of Health Sciences, Institute for Sport, Exercise Medicine and Lifestyle Research, Section Sports Medicine, University of Pretoria, Pretoria, South Africa.
authors.forename: Dina C
authors.initials: DC
authors.lastname: Janse van Rensburg
mesh_terms: D000208:Acute Disease / Q000453:epidemiology*; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012420:Running / Q000293:injuries* / Q000706:statistics & numerical data; D013019:South Africa / Q000453:epidemiology
keywords: Epidemiology; Illness; Infection; Running