Exercise-induced laryngeal obstruction (EILO) in athletes: a narrative review by a subgroup of the IOC Consensus on 'acute respiratory illness in the athlete'.

Exercise-induced laryngeal obstruction (EILO) is caused by paradoxical inspiratory adduction of laryngeal structures during exercise. EILO is an important cause of upper airway dysfunction in young individuals and athletes, can impair exercise performance and mimic lower airway dysfunction, such as asthma and/or exercise-induced bronchoconstriction. Over the past two decades, there has been considerable progress in the recognition and assessment of EILO in sports medicine. EILO is a highly prevalent cause of unexplained dyspnoea and wheeze in athletes. The preferred diagnostic approach is continuous visualisation of the larynx (via laryngoscopy) during high-intensity exercise. Recent data suggest that EILO consists of different subtypes, possibly caused via different mechanisms. Several therapeutic interventions for EILO are now in widespread use, but to date, no randomised clinical trials have been performed to assess their efficacy or inform robust management strategies. The aim of this review is to provide a state-of-the-art overview of EILO and guidance for clinicians evaluating and treating suspected cases of EILO in athletes. Specifically, this review examines the pathophysiology of EILO, outlines a diagnostic approach and presents current therapeutic algorithms. The key unmet needs and future priorities for research in this area are also covered.

Risk factors for not finishing an ultramarathon: 4-year study in 23,996 race starters, SAFER XXI.

BACKGROUND: Limited data support prerace 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 (56 km) race starters who completed a prerace 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 prerace medical screening history. RESULTS: Risk factors for DNF amongst 23,996 starters during the 56 km race included older age and females (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.

Pre-race screening and stratification predicts adverse events-A 4-year study in 29585 ultra-marathon entrants, SAFER X.

BACKGROUND: Pre-race screening and risk stratification in recreational endurance runners may predict adverse events (AEs) during a race. AIM: To determine if pre-race screening and risk stratification predict AEs during a race. METHODS: A total of 29 585 participants (Male 71.1%, average age = 42.1 years; Female 28.9%, average age = 40.2 years) at the Two Oceans ultra-marathon races (56 km) completed a pre-race medical screening questionnaire and were risk stratified into four pre-specified groups [very high risk (VHR; existing cardiovascular disease-CVD:3.2%), high risk (HR; risk factors for CVD:10.5%), intermediate risk (IR; existing other chronic disease, medication use or injury:53.3%), and low risk (LR:33.0%)]. Race starters, finishers, and medical encounters (ME) were recorded. Did-not-start (DNS) rate (per 1000 entrants that did-not-start), did-not-finish (DNF) rate (per 1000 starters that did-not-finish), AE rate [per 1000 starters that either DNF or had an ME], and ME rate (per 1000 starters with an ME) were compared across risk categories. RESULTS: Adverse events were significantly higher (per 1000 starters; 95%CI) in the VHR (68.9; 52.4-89.9:P = .0407) compared with the LR (51.3; 46.5-56.7). The DNS rate was significantly different between the IR (190.3; 184.0-196.9) and LR (207.4; 199.2-216.0: P = .0011). DNF rates were not different in the VHR (56.4; 41.9-75.9) compared to LR (44.2; 39.7-49.1: P = .1295), and ME rate was also not different between risk categories, however, VHR (12.9; 7.0-23.9) was approaching significance compared to LR (6.9; 5.2-9.1: P = .0662). CONCLUSION: Pre-race medical screening and risk stratification may identify athletes at higher risk of AEs. Further studies should be performed in larger cohorts to clarify the role of pre-race medical screening in reducing AEs in endurance runners.