Medical consequences in endurance sports - Two Oceans Marathon longitudinal study : an evaluation of participation guidelines in runners presenting with symptoms of acute illness before competition

Master Thesis


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University of Cape Town

Background: One of the most common clinical decisions a Sports and Exercise Medicine (SEM) physician is required to make is whether an athlete presenting with symptoms or signs of an acute illness can participate in exercise training or competition. Currently, a clinical tool, known as the ‘neck check’ is used to determine eligibility to participate in exercise training or competition athletes with acute illness. This original clinical tool, first described about 20 years ago, was based mainly on an abbreviated medical history and findings of a clinical examination were excluded. Symptoms of illness ‘above-the-neck’ e.g.sneezing, rhinorrhoea or sinus congestion constitute a ‘passed’ “neck check”, whereas ‘below-the-neck’ symptoms e.g.cough and/or systemic symptoms such as fever and myalgia, constitute a ‘failed’ “neck check”. However, in the current literature, there remain very few data regarding 1) the adherence of athletes to advice given following a ‘neck check’, and 2) whether the exercise performance (e.g.the ability to finish a race) or the development of medical complications during exercise is different in athletes who “passed” or “failed” the ‘neck check’. Objective The main objectives of this dissertation are: 1) to review the available evidence with respect to medical assessment and participation risk in endurance runners presenting with symptoms of acute illness before a road race; 2) to document the range of acute illnesses in runners presenting in the 3 days before a race; 3) to determine adherence to advice given by medical staff to these runners, and 4) to determine the effects of the outcomes of the medical assessment on running performance particularly, the ability to finish the race and the medical complications experienced during the race. These data are important to improve the medical care of runners (and other athletes) presenting with acute illness before training and competition. Methods: Phase 1: Review of the literature All literature relating to the epidemiology of acute illness in athletes, risk factors for illness, and participation risk, potential medical complications and effects on performance of exercising whilst ill were sourced using established electronic databases (PubMed, Medline, Google Scholar). In addition, literature related to the background of the ‘neck check’, as well as the evolution of the current RTP guidelines in athletes with acute illness were sourced. Phase 2: Research study In a prospective cohort study, 242 runners who presented to a pre-race registration medical facility with medical concerns were assessed by SEM physicians by means of medical history and physical examination (if indicated) using a specific Pre-Race acute Illness Medical Assessment (PRIMA group). 172 of these runners had evidence suggesting acute infective illness (PRIMA-I group) and 70 runners had non-infective complaints (PRIMA-N/I group). The epidemiology (prevalence rate = % runners) of runners with symptoms, signs and specific clinical diagnoses of acute illnesses were documented in the PRIMA-I group. Following clinical evaluation, all the runners in the PRIMA-I group were then advised regarding clearance to run the race, monitoring symptoms, or not running the race, using the ‘neck check’ as a guideline. Runners in the PRIMA cohort were then tracked during and immediately after the race, and the following parameters were compared to those in a control group of runners not presenting to the medical facility at registration (CON=53 734): 1) incidence of not starting of the race (per 1000 runners) (DNS rate), 2) incidence of not finishing the race in those who started (per 1000 runners) (DNF rate), and 3) incidence of medical complications during the race in those who started (per 1000 runners) (MC rate). Results Phase 1: Review The main finding of the review is the relative paucity in clinical data with respect to participation in athletes with acute illness. Upper respiratory tract symptoms are very common in athletes, and the risk factors are discussed. Furthermore, there are different aetiologies underlying athletes’ URT symptoms (other than infection). The documented risks of exercising when systemically ill include sudden cardiac death and reduced pulmonary function, splenic rupture in patients with infectious mononucleosis, and dehydration and electrolyte disturbances when exercising with acute gastro-intestinal illness. There is little evidence in the literature regarding the effects of illness on performance; these include reduced performance, non-participation and the potential effects of WARI (wheezing after respiratory tract infection). Evidence supporting the two aspects of the neck check is reviewed: the presumed safety of exercising with localised URT symptoms, and the perceived risk of exercising with lower respiratory tract or systemic symptoms. Clinical data are severely lacking, and the available data are based on self-reported symptomatology. There are no published data regarding the use of the ‘neck check’ as a participation guideline. Phase 2: In the PRIMA-I cohort of 172 runners, the most common symptoms were sinus congestion (40.1%), cough (38.2%), sore throat (37.8%) and runny nose (25.6%). More than half the cohort (57.5%) had a diagnosis of localised URTI. However, URTI with generalised symptoms was the single most common diagnosis (22.7%). In the PRIMA-I group, 41.3% of the runners failed the ‘neck check’. Compared with the CON group, there was no significant difference in the DNS rate in the PRIMA-I group. However, in those runners who were advised not to run, the DNS rate was 565 per 1000 runners, and this was significantly higher than that of the CON group (192 per 1000 runners) (p<0.0001). PRIMA-I race starters had a higher DNF rate (31 per 1000 runners), and runners with any medical concerns (PRIMA group) had a significantly higher DNF rate (37 per 1000 runners) compared to the CON group of runners who started the race (15 per 1000 runners) (p= 0.0329). There were no documented medical complications in the PRIMA-I group who started the race, while the MC rate of the CON group was 6.7 per 1000 runners. In runners in the PRIMA-I group who had been advised not to run, 43.5% were non-adherent, and started the race despite this advice. Conclusion: Our study indicates that localised upper respiratory tract infection is responsible for the majority of acute illness in a pre-race cohort of runners. Furthermore, the data provide some evidence that it is safe for runners with acute illness to exercise if they pass the ‘neck check’. However, presenting to a pre-race registration medical facility, failing the ‘neck check’ and receiving advice against participation appear to increase the risk of not finishing a race. There is also concern about the high rate of non-adherence to advice given by the SEM physician. Finally, a pre-race registration medical assessment for runners with acute illness may reduce the risk of developing short-term medical complications during the race.

Includes bibliographical references.