Risk factors associated with medical encounters in ultramarathon race starters - Data from 103,131 race starters over 90 km: SAFER XLI.

OBJECTIVES: To identify the risk factors associated with all medical encounters (MEs) and serious/life-threatening MEs (SLMEs) during the Comrades Marathon. DESIGN: Prospective cohort study, with cross-sectional analyses. METHODS: During the 2014-2019 Comrades Marathon, all MEs (including SLMEs) were recorded in 103,131 starters. For both all MEs and SLMEs, the following risk factors were explored: sex, age, route ("up" vs. "down" race), previous Comrades experience (yes/no), wet-blub globe temperature (WBGT) and race pace. Incidence (per 1000 starters; 95%CI), and the incidence ratio (IR; 95%CI) are presented. RESULTS: For all MEs, being female was a significant risk factor (females vs. males IR = 1.47, p < 0.0001), and age was only marginally significant (p = 0.0167). Therefore factors for all MEs were adjusted for sex. Other factors significantly associated with all MEs were: higher WBGT (highest WBGT compared to lowest, IR = 1.33, p = 0.0003), race pace (highest risk for those who finish either among the first quarter [IR = 1.49] or last quarter [IR = 1.46] compared to middle pace; p < 0.0001) and the route ("down" vs. "up": IR = 1.11; p = 0.0181). Factors associated with higher risk for SLMEs were: females (IR = 1.9; p = 0.0003), "down" vs. "up" route (IR = 1.37; p = 0.0306) and race pace (slower and faster runners vs. mid (6.4-7.1 min/km) race pace category (IR > 2.1, p < 0.0001)). CONCLUSIONS: Intrinsic (female, faster and slower race pace) and extrinsic (higher WBGT and the "down" route) are novel risk factors associated with all MEs at this event. These can be considered by the race organizers and the medical team to develop and implement prevention strategies.

Sex, training variables, history of chronic disease, and chronic injury are risk factors associated with a history of exercise-associated muscle cramping in 10,973 ultramarathon race entrants: a safer XXXVIII study.

BACKGROUND: The prevalence of a history of exercise-associated muscle cramping (hEAMC) among ultramarathon runners is high. While the Comrades is one of the most popular mass community-based participation ultramarathons (90 km) globally, research on the epidemiology, clinical characteristics, and risk factors of entrants' lifetime hEAMC are scarce. This research aimed to describe the epidemiology, clinical characteristics, and risk factors of hEAMC among Comrades Marathon entrants. METHODS: This was a retrospective, cross-sectional study in which 10973 race entrants of the 2022 Comrades Marathon participated. Entrants completed a prerace medical screening questionnaire that included questions related to the lifetime prevalence (%; 95% CI), severity, treatment and risk factors (demographics, training/racing variables, chronic disease/allergies, injury) for EAMC. RESULTS: One thousand five hundred eighty-two entrants reported hEAMC in their lifetime (14.4%; 95% CI: 13.77-15.09). There was a significantly (P<0.01) higher prevalence of male (16.10%; 95% CI:15.34-16.90) than female (8.31%; 95% CI: 7.27-9.50) entrants with hEAMC (PR=1.94; 95% CI:1.68-2.23). The prevalence of hEAMC was highest in entrants with a: 1) 1 disease increase in composite disease score (PR=1.31; 95% CI:1.25-1.39); 2) history of collapse (PR=1.87; 95% CI 1.47-2.38); 3) past chronic musculoskeletal (MSK) injury (PR=1.71; 95% CI 1.50-1.94); and 4) MSK injury in the previous 12 months (PR=2.38;95% CI: 2.05-2.77). Training-related risk factors included an increase of 10 km weekly running distance (PR=0.97; 95% CI:0.95-0.99) and a training pace increase of 1min/ km (slower) (PR=1.07; 95% CI:1.03-1.12). CONCLUSIONS: Future research should investigate the causal relationship between risk factors identified and hEAMC in ultramarathon runners. Findings from this study could assist in effective anticipation and adequate planning for treating EAMC encounters during community-based mass participation events.

Increased number of symptoms during the acute phase of SARS-CoV-2 infection in athletes is associated with prolonged time to return to full sports performance-AWARE VIII.

PURPOSE: The aim of the study was to identify factors associated with prolonged time to return to full performance (RTFP) in athletes with recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: Prospective cohort study with cross sectional analysis. A total of 84 athletes with confirmed SARS-CoV-2 infection assessed at a coronavirus disease 2019 recovery clinic gave a history of: age, sex, type/level of sport, co-morbidities, pre-infection training hours, and 26 acute SARS-CoV-2 symptoms from 3 categories ("nose and throat", "chest and neck", and "whole body"/systemic). Data on days to RTFP were obtained by structured interviews. Factors associated with RTFP were: demographics, sport participation, history of co-morbidities, pre-infection training history, acute symptoms (type, number). Outcomes were: (a) days to RTFP (median, interquartile range (IQR)) in asymptomatic (n = 7) and symptomatic athletes (n = 77), and (b) hazard ratios (HRs; 95% confidence interval) for symptomatic athletes with vs. without a factor (univariate, multiple models). HR < 1 was predictive of higher percentage chance of prolonged RTFP. Significance was p < 0.05. RESULTS: Days to RTFP were 30 days (IQR: 23-40) for asymptomatic and 64 days (IQR: 42-91) for symptomatic participants (p > 0.05). Factors associated with prolonged RTFP (univariate models) were: females (HR = 0.57; p = 0.014), endurance athletes (HR = 0.41; p < 0.0001), co-morbidity number (HR = 0.75; p = 0.001), respiratory disease history (HR = 0.54; p = 0.026). In symptomatic athletes, prolonged RTFP (multiple models) was significantly associated with increased "chest and neck" (HR = 0.85; p = 0.017) and "nose and throat" (HR = 0.84; p = 0.013) symptoms, but the association was more profound between prolonged RFTP and increased total number of "all symptoms" (HR = 0.91; p = 0.001) and "whole body"/systemic (HR = 0.82; p = 0.007) symptoms. CONCLUSION: A larger number of total symptoms and specifically "whole body"/systemic symptoms during the acute phase of SARS-CoV-2 infection in athletes is associated with prolonged RTFP.

A comparison of two pre-race medical screening tools in 5771 running race entrants-SAFER XXVIII.

OBJECTIVE: To determine if two pre-race screening tools (abbreviated tool of two open-ended pre-race medical screening questions [ABBR] vs. a full pre-race medical screening tool [FULL]) identify running race entrants at higher risk for medical encounters (MEs) on race day. METHODS: 5771 consenting race entrants completed both an ABBR and a FULL pre-race screening questionnaire for the 2018 Comrades Marathon (90 km). ABBR tool questions were (1) allergies, and (2) known medical conditions and/or prescription medication use. The FULL tool included multiple domains of questions for chronic diseases including cardiovascular disease (CVD), symptoms, risk factors, allergies and medication use. ABBR responses were manually coded and compared to the FULL tool. The prevalence (%: 95%CI), and the test for equality of prevalence of entrants identified by the ABBR vs. FULL tool is reported. RESULTS: The ABBR identified fewer entrants with allergies (ABBR = 7.9%; FULL = 10.4%: p = 0.0001) and medical conditions/medication use (ABBR = 8.9%; FULL = 27.4%: p = 0.0001). The ABBR tool significantly under-reported entrants with history of cardiovascular disease (CVD), CVD risk factors, other chronic diseases and prescription medication vs. the FULL tool (p = 0.0001). The ABBR tool identified fewer entrants in the "high" (ABBR = 3.4%; FULL = 12.4%) and "very high" risk (ABBR = 0.5%; FULL = 3.4%) categories for race day MEs (p = 0.0001). CONCLUSIONS: An abbreviated pre-race screening tool significantly under-estimates chronic medical conditions, allergies, and race entrants at higher risk for MEs on race day, compared with a full comprehensive screening tool. We recommend that a full pre-race medical screening tool be used to identify race entrants at risk for MEs.

Risk factors associated with gradual onset running-related injuries in 5770 ultramarathon race entrants - SAFER XXXII.

BACKGROUND: There is limited evidence available on contributing factors for gradual onset running-related injuries (GORRIs) in ultramarathon runners. The aim was to determine if selected risk factors were associated with a history of GORRIs in 90-km ultramarathon race entrants. METHODS: Descriptive cross-sectional study. GORRI and medical data using an online pre-race medical screening tool was collected from 5770 consenting race entrants from the 2018 90-km Comrades Marathon. Selected risk factors associated with 12-months history of GORRIs (age, sex, training, chronic diseases and allergies) were analyzed using a multiple model (Poisson regression). Prevalence and prevalence ratios (PR, 95% CIs) are reported. RESULTS: The overall 12-month prevalence of GORRIs was 11.6% (95% CI: 10.8-12.5) and this was higher in females versus males (PR=1.6; 1.4-1.9) (P<0.0001). Novel independent risk factors associated with a history of GORRIs were: history of chronic disease (PR=1.3; P=0.0063); history of allergies (PR=1.7 increased risk for every disease; P<0.0001); fewer training sessions/week (PR=0.8 decreased risk for every two additional training sessions per week; P=0.0005); and increased number of years as a recreational runner (PR=1.1 increased risk per 5 years of running; P=0.0158). CONCLUSIONS: There is a complex interaction between the internal and external risk factors associated with GORRIs in 90-km distance runners. These data can inform injury prevention programs targeted at subgroups of ultradistance runners.