Patellofemoral Pain Syndrome Is Associated With Chronic Disease and Allergies in 60 997 Distance Runner Race Entrants: SAFER XXX Study.

OBJECTIVE: Patellofemoral pain syndrome (PFPS) is a common running-related injury. Independent risk factors associated with PFPS have not been described in a large cohort of distance runners. DESIGN: Descriptive, cross-sectional study. SETTING: 21.1 and 56 km Two Oceans Marathon races (2012-2015). PARTICIPANTS: 60 997 race entrants. ASSESSMENT OF RISK FACTORS: Participants completed a compulsory prerace medical screening questionnaire (history of PFPS in the past 12 months, n = 362; no injury history, n = 60 635). Selected risk factors associated with a history of PFPS were explored using univariate & multivariate analyses: demographics, training/running variables, history of chronic diseases (composite chronic disease score), and any allergy. MAIN OUTCOME MEASURES: Prevalence ratios (PRs, 95% confidence intervals). RESULTS: Risk factors associated with PFPS (univariate analysis) were increased years of recreational running (PR = 1.09; P = 0.0107), older age (>50 years), and chronic diseases (PR > 2): gastrointestinal disease (PR = 5.06; P < 0.0001), cardiovascular disease (CVD) (PR = 3.28; P < 0.0001), nervous system/psychiatric disease (PR = 3.04; P < 0.0001), cancer (PR = 2.83; P = 0.0005), risk factors for CVD (PR = 2.42; P < 0.0001), symptoms of CVD (PR = 2.38; P = 0.0397), and respiratory disease (PR = 2.00; P < 0.0001). Independent risk factors (multivariate analysis) associated with PFPS (adjusted for age, sex, and race distance) were a higher chronic disease composite score (PR = 2.68 increased risk for every 2 additional chronic diseases; P < 0.0001) and a history of allergies (PR = 2.33; P < 0.0001). CONCLUSIONS: Novel independent risk factors associated with PFPS in distance runners are a history of multiple chronic diseases and a history of allergies. Identification of chronic diseases and allergies should be considered as part of the clinical assessment of a runner presenting with a history of PFPS.

Chronic Disease, Allergies, and Increased Years of Running Are Risk Factors Predicting Gradual Onset Running-Related Injuries in Ultramarathon Runners-SAFER XIX Study in 29 585 Race Entrants.

OBJECTIVES: To identify risk factors that predict gradual onset running-related injuries (GORRIs) in ultramarathon runners entering a mass community-based event. DESIGN: Descriptive cross-sectional study. SETTING: Two Oceans 56 km ultramarathon 2012 to 2015. PARTICIPANTS: Race entrants (n = 42 003) completed a compulsory pre-race medical history questionnaire; 29 585 (70.4%) of entrants consented. DEPENDENT/OUTCOME VARIABLE: A history of GORRIs in the past 12 months among race entrants. MAIN OUTCOME MEASURES: In a multi-variate model, runner demographics, training variables (years of recreational running, weekly running distance, training running speed), history of chronic disease (composite score), and history of allergies were included as factors predicting GORRIs. Prevalence (%) and prevalence ratios (PR, 95% CIs) are reported. RESULTS: The lifetime prevalence of GORRIs in ultramarathon runners was 24.4%. Independent factors predicting GORRIs were: higher chronic disease composite score (PR = 2.05 times increase risk for every 2 additional chronic diseases; P < 0.0001), history of allergies (PR = 1.66; P < 0.0001), increased years of recreational running (PR = 1.07 times increased risk for every 5 year increase in running; P < 0.0001), lower average weekly running distance (PR = 0.98 times decreased risk for every 15 km increase weekly running distance; P < 0.0001), and slower average training running speed (PR = 0.96 times decreased risk for every km/h increase in training running speed; P < 0.0001). CONCLUSIONS: Novel risk factors predicting GORRIs are increased number of chronic diseases and a history of allergies. These factors, together with training variables (years of recreational running, weekly running distance, and training running speed) can be targeted to develop and implement injury prevention, treatment, and rehabilitation interventions in ultramarathon runners.

Independent Risk Factors Predicting Gradual Onset Injury in 2824 Trail Running Race Entrants: SAFER XVIII Study.

INTRODUCTION: Trail running is characterized by elevation changes, with uneven and varying running surfaces. Risk factors that may predict gradual-onset running-related injuries (GORRIs) in short-distance trail running have not been explored. The objective was to determine risk factors that predict GORRIs in trail running race entrants who entered mass community-based trail running events. METHODS: In this descriptive cross-sectional study, data were collected prospectively from a prerace medical screening questionnaire over 4 trail run events held annually. Using a Poisson regression model, runner demographics, race distance, running training/racing variables, history of chronic diseases (number of chronic diseases reported as a cumulative "chronic disease composite score"), and allergies were investigated to determine factors predicting self-reported GORRI history in the previous 12 mo. RESULTS: This study included 2824 race entrants (80% of entrants). The retrospective annual incidence for GORRIs was 13%. Independent risk factors predicting GORRIs were longer race distance (P<0.0001), increasing chronic disease composite score (P=0.0012), and a history of allergies (P=0.0056). The lower limb (94%) was the main anatomic region of GORRIs, and soft tissue injuries accounted for most (83%) GORRIs. Common specific GORRIs were iliotibial band syndrome (22%), Achilles tendon injury (10%), and hamstring injury (9%). CONCLUSIONS: Independent risk factors predicting GORRIs among trail running entrants included longer race distance, a higher chronic disease composite score, and a history of allergies. This study has highlighted trail running race entrants at risk for sustaining GORRIs who could be targeted for future injury prevention interventions.

Match injury incidence during the Super Rugby tournament is high: a prospective cohort study over five seasons involving 93 641 player-hours.

OBJECTIVES: To determine the incidence and nature of injuries in the Super Rugby tournament over a 5-year period. METHODS: 482 male professional rugby union players from six South African teams participating in the Super Rugby tournament were studied (1020 player-seasons). Medical staff of participating teams (2012-2016 tournaments) recorded all time loss injuries (total injuries and match injuries) and exposure hours (93 641 total playing hours; 8032 match hours). Injury incidence, injured player proportion, severity (time lost), anatomical location, tissue type and activity/phase during which injury occurred are reported. RESULTS: The overall incidence of match injuries (per 1000 player-hours; 95% CI) for each year was as follows: 2012 (83.3; 69.4-99.2); 2013 (115.1; 98.7-133.5); 2014 (95.9; 80.8-113.1), 2015 (112.3; 96.6-129.9) and 2016 (93.2; 79.9-107.9). The injured player proportion for each year was as follows: 2012 (54.6%); 2013 (49.4%); 2014 (52.0%); 2015 (50.0%); and 2016 (39.8%). The thigh, knee, head/face and shoulder/clavicle are the most frequently injured locations, and muscle/tendon and joint/ligament injuries account for the majority of injuries. Most injuries (79%) occur in contact situations, in particular during a tackle (54%). CONCLUSION: The incidence of match injuries and the injured player proportion in South African teams competing in the Super Rugby tournament is high. Match injury incidence is consistently higher than previously reported for senior male rugby players at elite/professional level. Targeted risk management strategies are therefore needed in the Super Rugby tournament to manage risk of injury.

The Injury and Illness Profile of Male and Female Participants in a 94.7 km Cycle Race: A Cross-Sectional Study.

OBJECTIVE: To describe the incidence and patterns of injury and illness of male and female participants during a 94.7 km distance cycling event. DESIGN: Descriptive study. SETTING: Momentum 94.7 Cycle Challenge 2014. PARTICIPANTS: All 23 055 race starters (males = 17 520, females = 5236, not specified = 299). MAIN OUTCOME MEASURES: The incidence and type of all medical complaints and difference between sexes. RESULTS: Incidence (per 1000 race starters) of all medical complaints was 38.69 (males = 36.52, females = 38.39), adverse medical events 11.88 (males = 10.73, females = 16.42) and serious adverse events 1.3 (males = 0.86, females = 2.67). The incidence of nontraumatic medical complaints was 32.49 (males = 33.39, females = 31.32) and of traumatic injuries was 3.99 (males = 3.14, females = 7.07). Females compared to males had a higher risk of sustaining traumatic injuries (P < 0.001), central nervous system, (P = 0.0062) and eye complaints (P = 0.0107). Most complaints (80.6%) were reported for the musculoskeletal system. Males 10-15 years (P = 0.0013) and females 23-39 years (P = 0.0336), and older than 50 years (P = 0.0002) had a higher than expected risk for traumatic injuries. CONCLUSIONS: Medical complaints ratio reported was 1:26 (males = 1:28, females = 1:26) in all starters during the cycling event. Cyclists that did not finish the race (adverse events) were 1:84 (males = 1:93, females = 1:61). Serious adverse events that required hospitalization were 1:769 (males = 1:1163, females = 1:374). The majority of admissions were for traumatic injuries, followed by cardiovascular complaints. Results from this study indicated that a wide spectrum of medical complaints can be expected during such an event with a higher risk for females to sustain traumatic injuries and to encounter central nervous system and eye complaints. Information regarding the pattern and type of medical encounters can prove useful during planning and management of similar future events.

Sport, sex and age increase risk of illness at the Rio 2016 Summer Paralympic Games: a prospective cohort study of 51 198 athlete days.

OBJECTIVE: To describe the epidemiology of illness at the Rio 2016 Summer Paralympic Games. METHODS: A total of 3657 athletes from 78 countries, representing 83.5% of all athletes at the Games, were monitored on the web-based injury and illness surveillance system (WEB-IISS) over 51 198 athlete days during the Rio 2016 Summer Paralympic Games. Illness data were obtained daily from teams with their own medical support through the WEB-IISS electronic data capturing systems. RESULTS: The total number of illnesses was 511, with an illness incidence rate (IR) of 10.0 per 1000 athlete days (12.4%). The highest IRs were reported for wheelchair fencing (14.9), para swimming (12.6) and wheelchair basketball (12.5) (p<0.05). Female athletes and older athletes (35-75 years) were also at higher risk of illness (both p<0.01). Illnesses in the respiratory, skin and subcutaneous and digestive systems were the most common (IRs of 3.3, 1.8 and 1.3, respectively). CONCLUSION: (1) The rate of illness was lower than that reported for the London 2012 Summer Paralympic Games; (2) the sports with the highest risk were wheelchair fencing, para swimming and wheelchair basketball; (3) female and older athletes (35-75 years) were at increased risk of illness; and (4) the respiratory system, skin and subcutaneous system and digestive system were most affected by illness. These results allow for comparison at future Games.

Underlying Chronic Disease, Medication Use, History of Running Injuries and Being a More Experienced Runner Are Independent Factors Associated With Exercise-Associated Muscle Cramping: A Cross-Sectional Study in 15778 Distance Runners.

BACKGROUND: Exercise-associated muscle cramping (EAMC) is a significant medical complication in distance runners, yet factors associated with EAMC are poorly documented. OBJECTIVE: To document risk factors associated with EAMC in runners. DESIGN: Cross-sectional study. SETTING: Two ocean races (21.1 km, and 56 km). PARTICIPANTS: Fifteen thousand seven hundred seventy-eight race entrants. METHODS: Participants completed a prerace medical history screening tool including: training, cardiovascular disease (CVD), risk factors for, and symptoms of CVD, history of diseases affecting major organ systems, cancer, allergies, medication use, and running injury. Runners were grouped as having a history of EAMC (hEAMC group = 2997) and a control group (Control = 12 781). RESULTS: Independent factors associated with a higher prevalence ratio (PR) of hEAMC were any risk factor for CVD (PR = 1.16; P = 0.0002), symptoms of CVD (PR = 2.38; P < 0.0001), respiratory disease (PR = 1.33; P < 0.0001), gastrointestinal disease (PR = 1.86; P < 0.0001), nervous system or psychiatric disease (PR = 1.51; P < 0.0001), kidney or bladder disease, (PR = 1.60; P < 0.0001), haematological or immune disease (PR = 1.54; P = 0.0048), cancer (PR = 1.34; P = 0.0031), allergies (PR = 1.37; P < 0.0001), regular medication use (PR = 1.80; P < 0.0001), statin use (PR = 1.26; P = 0.0127), medication use during racing (PR = 1.88; P < 0.0001), running injury (PR = 1.66; P < 0.0001), muscle injury (PR = 1.82; P < 0.0001), tendon injury (PR = 1.62; P < 0.0001), and runners in the experienced category (PR = 1.22; P < 0.0001). CONCLUSION: Novel risk factors associated with EAMC in distance runners were underlying chronic disease, medication use, a history of running injuries, and experienced runners. These factors must be identified as possible associations, and therefore be considered in the diagnosis and treatment of EAMC.

Novel Factors Associated With Analgesic and Anti-inflammatory Medication Use in Distance Runners: Pre-race Screening Among 76 654 Race Entrants-SAFER Study VI.

OBJECTIVE: Analgesic/anti-inflammatory medication (AAIM) increases the risk of medical complications during endurance races. We determined how many runners use AAIM before or during races, AAIM types, and factors associated with AAIM use. DESIGN: Cross-sectional study. SETTING: 21.1-km and 56-km races. PARTICIPANTS: Seventy-six thousand six hundred fifty-four race entrants. METHODS: Participants completed pre-race medical screening questions on AAIM use, running injury or exercise-associated muscle cramping (EAMC) history, and general medical history. MAIN OUTCOME MEASURES: Analgesic/anti-inflammatory medication use, types of AAIM (% runners; 95% confidence interval), and factors associated with AAIM use (sex, age, race distance, history of running injury or EAMC, and history of chronic diseases) [prevalence ratio (PR)]. RESULTS: Overall, 12.2% (12.0-12.5) runners used AAIM 1 week before and/or during races (56 km = 18.6%; 18.0-19.1, 21.1 km = 8.3%; 8.1-8.6) (P < 0.0001). During races, nonsteroidal anti-inflammatory drugs (NSAIDs) (5.3%; 5.1-5.5) and paracetamol (2.6%; 2.4-2.7) were used mostly. Independent factors (adjusted PR for sex, age, and race distance; P < 0.0001) associated with AAIM use were running injury (2.7; 2.6-2.9), EAMC (2.0; 1.9-2.1), cardiovascular disease (CVD) symptoms (2.1; 1.8-2.4), known CVD (1.7; 1.5-1.9), CVD risk factors (1.6; 1.5-1.6), allergies (1.6; 1.5-1.7), cancer (1.3; 1.1-1.5), and respiratory (1.7; 1.6-1.8), gastrointestinal (2.0; 1.9-2.2), nervous system (1.9; 1.7-2.1), kidney/bladder (1.8; 1.6-2.0), endocrine (1.5; 1.4-1.7), and hematological/immune (1.5; 1.2-1.8) diseases. CONCLUSIONS: 12.2% runners use AAIM before and/or during races, mostly NSAIDs. Factors (independent of sex, age, and race distance) associated with AAIM use were history of injuries, EAMC, and numerous chronic diseases. We suggest a pre-race screening and educational program to reduce AAIM use in endurance athletes to promote safer races.

Older females are at higher risk for medical complications during 21 km road race running: a prospective study in 39 511 race starters--SAFER study III.

BACKGROUND: The half-marathon (21 km) race is a very popular mass community-based distance running event. It is important to determine risk factors for medical complications during these events, so that prevention programmes can be developed. OBJECTIVE: To determine risk factors associated with medical complications during 21 km road running events. DESIGN: Prospective study. SETTING: Two Oceans half-marathon (21 km) races. PARTICIPANTS: 39 511 starters in the 21 km race. METHODS: Medical complications (defined as any runner requiring assessment by a doctor at the race medical facility or a local hospital on race day) were recorded over a 4-year study period. Medical complications were subdivided according to the system affected and by final diagnosis. A Poisson regression model was used to determine risk factors for any medical complication and more common specific complications. RESULTS: Independent risk factors for medical complication during 21 km running were older female runners (women >50 vs ≤50 years; p<0.0001) and year of observation (2008 vs 2011; p=0.0201: 2009 vs 2011: p=0.0019; 2010 vs 2011: p=0.0096). Independent risk factors for specific common medical complications were: postural hypotension (women, slow running pace), musculoskeletal complications (less running experience, slower running pace) and dermatological complications (women). CONCLUSIONS: Older female runners are at higher risk of developing medical complications during 21 km road running races. Environmental conditions in a particularly cold climate may also play a role. Less running experience and slower running pace are associated with specific medical complications. Medical staff can now plan appropriate care on race days, and interventions can be developed to reduce the risk of medical complications in 21 km races.

Less experience and running pace are potential risk factors for medical complications during a 56 km road running race: a prospective study in 26 354 race starters--SAFER study II.

BACKGROUND: It is important to identify risk factors associated with medical complications during ultra-marathons so that prevention programmes can be developed. OBJECTIVE: To determine risk factors for medical complications during ultra-marathons. DESIGN: Prospective study. SETTING: Two Oceans ultra-marathon (56 km) races. PARTICIPANTS: 26 354 race starters. METHODS: Medical complications (defined as any runner requiring assessment by a doctor at the race medical facility or a local hospital on race day) were recorded over 4 years. Complications were subdivided according to the system that was affected and by final diagnosis. A Poisson regression model was used to determine risk factors for any medical complication and for more common specific complications. RESULTS: Risk factors for medical complications during 56 km road races were less running experience (≤1 medal vs 2-4 medals, p=0.0097), and both fastest (<6 vs 6-7 min/km, p=0.0051) and slowest (>7 vs 6-7 min/km, p<0.0001) running pace category. Year of observation was also associated with risk of complications (2009 vs 2008, p=0.0176; 2009 vs 2010, p=0.0007; 2010 vs 2011, p=0.0112). Risk factors for specific common medical complications were: postural hypotension (slowest pace), serious exercise-associated muscle cramping (older age, fastest pace), gastrointestinal complications (slowest pace) and dermatological complications (fastest pace). CONCLUSIONS: Less experience and running at either a slow or a fast pace were risk factors for complications during 56 km road running. Annual variation may also affect risk. Risk factors for specific medical complications were also identified. These data form the basis of further studies to assist medical staff to plan appropriate care at races.

More than 50% of players sustained a time-loss injury (>1†day of lost training or playing time) during the 2012 Super Rugby Union Tournament: a prospective cohort study of 17,340 player-hours.

BACKGROUND: Professional Rugby Union is a contact sport with a high risk of injury. OBJECTIVE: To document the incidence and nature of time-loss injuries during the 2012 Super Rugby tournament. DESIGN: Prospective cohort study. SETTING: 2012 Super Rugby tournament (Australia, New Zealand, South Africa). PARTICIPANTS: 152 players from 5 South African teams. METHODS: Team physicians collected daily injury data through a secure, web-based electronic platform. Data included size of the squad, type of day, main player position, training or match injury, hours of play (training and matches), time of the match injury, mechanism of injury, main anatomical location of the injury, specific anatomical structure of the injury, the type of injury, the severity of the injury (days lost). RESULTS: The proportion (%) of players sustaining a time-loss injury during the tournament was 55%, and 25% of all players sustained >1 injury. The overall incidence rate (IR/1000 player-hours) of injuries was 9.2. The IR for matches (83.3) was significantly higher than for training (2.1) and the IR was similar for forwards and backs. Muscle/tendon (50%) and joint/ligament (32.7%) injuries accounted for >80% of injuries. Most injuries occurred in the lower (48.1%) and upper limb (25.6%). 42% of all injuries were moderate (27.5%) or severe (14.8%), and tackling (26.3%) and being tackled (23.1%) were the most common mechanisms of injury. The IR of injuries was unrelated to playing at home compared with away (locations ≥6 h time difference). CONCLUSIONS: 55% of all players were injured during the 4-month Super Rugby tournament (1.67 injuries/match). Most injuries occurred in the lower (knee, thigh) or upper limb (shoulder, clavicle). 42% of injuries were severe enough for players to not play for >1 week.

Risk factors associated with a history of iliotibial band syndrome (hITBS) in distance runners: a cross-sectional study in 76 654 race entrants - a SAFER XXXIII study.

BACKGROUND: Despite the numerous health benefits of distance running, it is also associated with the development of 'gradual onset running-related injuries' (GORRIs) one of which is Iliotibial Band Syndrome (ITBS). Novel risk factors associated with a history of ITBS (hITBS) have not been described in a large cohort of distance runners. OBJECTIVE: To identify risk factors associated with hITBS in distance runners. DESIGN: Descriptive cross-sectional study. SETTING: 21.1 km and 56 km Two Oceans Marathon races (2012-2015). PARTICIPANTS: 106 743 race entrants completed the online pre-race medical screening questionnaire. A total of 1 314 runners confirmed an accurate hITBS diagnosis. METHODS: Selected risk factors associated with hITBS explored included: demographics (race distance, sex, age groups), training/running variables, history of existing chronic diseases (including a composite chronic disease score) and history of any allergy. Prevalence (%) and prevalence ratios (PR; 95% CI) are reported (uni- & multiple regression analyzes). RESULTS: 1.63% entrants reported hITBS in a 12-month period. There was a higher (p < 0.0001) prevalence of hITBS in the longer race distance entrants (56 km), females, younger entrants, fewer years of recreational running (PR = 1.07; p = 0.0009) and faster average running speed (PR = 1.02; p = 0.0066). When adjusted for race distance, sex, age groups, a higher chronic disease composite score (PR = 2.38 times increased risk for every two additional chronic diseases; p < 0.0001) and a history of allergies (PR = 1.9; p < 0.0001) were independent risk factors associated with hITBS. CONCLUSION: Apart from female sex, younger age, fewer years of running and slower running speed, two novel independent risk factors associated with hITBS in distance runners are an increased number of chronic diseases and a history of allergies. Identifying athletes at higher risk for ITBS can guide healthcare professionals in their prevention and rehabilitation efforts.

Collagen genes and exercise-associated muscle cramping.

OBJECTIVE: The authors hypothesized that variants within genes, such as COL5A1, COL3A1, COL6A1, and COL12A1, that code for connective tissue components of the musculoskeletal system may modulate susceptibility to exercise-associated muscle cramping (EAMC). Specifically, the aim of this study was to investigate if the COL5A1 rs12722 (C/T), COL3A1 rs1800255 (G/A), COL6A1 rs35796750 (T/C), and COL12A1 rs970547 (A/G) polymorphisms are associated with a history of EAMC. DESIGN: Retrospective genetic case-control association study. SETTING: Participants were recruited at triathlon and ultra-marathon events and were asked to report physical activity, medical history, and cramping history. PARTICIPANTS: One hundred sixteen participants with self-reported history of EAMC within the past 12 months before an ultra-endurance event were included as cases in this study (EAMC group). One hundred fifty participants with no self-reported history of previous (lifelong) EAMC were included as controls (NON group). INTERVENTIONS: All participants were genotyped for the selected variants. MAIN OUTCOME MEASURES: Differences in genotype frequency distributions, for COL5A1 rs12722, COL3A1 rs1800255, COL6A1 rs35796750, and COL12A1 rs970547, among the cases and controls. RESULTS: The COL5A1 CC genotype was significantly overrepresented (P = 0.031) among the NON group (21.8%) when compared with the EAMC group (11.1%). No significant genotype differences were found for the COL3A1 (P = 0.828), COL6A1 (P = 0.300), or COL12A1 (P = 0.120) genotypes between the EAMC and NON groups. CONCLUSIONS: This study identified, for the first time, the COL5A1 gene as a potential marker for a history of EAMC.

Chronic diseases and allergies are risk factors predictive of a history of Medial Tibial Stress Syndrome (MTSS) in distance runners: SAFER study XXIV.

BACKGROUND: Medial Tibial Stress Syndrome (MTSS) is one of the most common causes of exercise-associated lower leg pain in distance runners. AIM: To identify risk factors predictive of a history of MTSS in distance runners entering the Two Oceans Marathon races (21.1 km and 56 km). DESIGN: Cross-sectional study. SETTING: 2012 to 2015 Two Oceans Marathon races (21.1 km and 56 km). PARTICIPANTS: Consenting race entrants. METHODS: 106,743 race entrants completed an online pre-race medical screening questionnaire. 76,654 consenting runners (71.8%) were studied. 558 verified MTSS injuries were reported in the previous 12 months. Risk factors predictive of a history of MTSS were explored using uni - & multivariate analyses: demographics (race distance, sex, and age groups), training/racing history, history of chronic diseases, allergies, and medication use. RESULTS: Independent risk factors predictive of a history of MTSS (adjusted for sex, age group, and race distance) were a higher chronic disease composite score (PR = 3.1 times increase risk for every two additional chronic diseases; p < 0.0001) and a history of allergies (PR = 1.9; p < 0.0001). Chronic diseases (PR > 2) predictive of a history of MTSS were: symptoms of CVD (PR = 4.2; p < 0.0001); GIT disease (PR = 3.3; p < 0.0001); kidney/bladder disease (PR = 3.3; p < 0.0001); nervous system/psychiatric disease (PR = 3.2; p < 0.0001); respiratory disease (PR = 2.9; p < 0.0001) a history of CVD (PR = 2.9; p < 0.0001); and risk factors of CVD (PR = 2.4; p < 0.0001) (univariate analysis). Average running speed was associated with higher risk of MTSS. CONCLUSION: Novel independent risk factors predictive of a history of MTSS in distance runners (56 km, 21.1 km) were multiple chronic diseases and a history of allergies. Identifying athletes at higher risk for MTSS can guide healthcare professionals in their prevention and rehabilitation efforts.

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.

The illness burden of gastrointestinal illness is two times higher if it is associated with systemic symptoms and signs: a cross-sectional study of the super rugby tournament over 5 seasons (102,738 player-days).

BACKGROUND: Gastrointestinal tract illness (GITill) in rugby players is underreported. The incidence, severity (% time loss illness, days lost per illness) and burden of GITill with/without systemic symptoms and signs in professional South African male rugby players during the Super Rugby tournament (2013-2017) are reported. METHODS: Team physicians completed daily illness logs of players (N.=537; 1141 player-seasons, 102738 player-days). The incidence (illnesses/1000 player-days, 95% CI), severity (% ≥1-day time-loss; days until return-to-play [DRTP]/single illness [mean: 95% CI]) and illness burden (IB: days lost to illness/1000 player-days) for the subcategories of GITill with/without systemic symptoms and signs (GITill+ss; GITill-ss), and gastroenteritis with/without systemic symptoms and signs (GE+ss; GE-ss) are reported. RESULTS: The incidence of all GITill was 1.0 (0.8-1.2). Incidence was similar for GITill+ss 0.6 (0.4-0.8) and GITill-ss 0.4 (0.3-0.5; P=0.0603). Incidence of GE+ss 0.6 (0.4-0.7) was higher than GE-ss 0.3 (0.2-0.4; P=0.0045). GITill caused ≥1-day time-loss in 62% of cases (GE+ss 66.7%; GE-ss 53.6%). GITill caused an average of 1.1 DRTP/single GITill, which was similar for subcategories. IB of GITill+ss was higher than GITill-ss (IB Ratio: 2.1 [1.1-3.9; P=0.0253]). IB for GITill+ss is 2 times higher than GITill-ss (IB Ratio: 2.1 [1.1-3.9]; P=0.0253); and GE+ss >3 times higher than GE-ss (IB Ratio: 3.0 [1.6-5.8]; P=0.0007). CONCLUSIONS: GITill accounted for 21.9% of all illnesses during the Super Rugby tournament, with >60% of GITill resulting in time-loss. The average DRTP/single illness was 1.1. GITill+ss and GE+ss resulted in higher IB. Targeted interventions to reduce the incidence and severity of GITill+ss and GE+ss should be developed.

Elite athletes travelling to international destinations >5 time zone differences from their home country have a 2-3-fold increased risk of illness.

BACKGROUND: Illness accounts for a significant proportion of consultations with a team physician travelling with elite athletes. OBJECTIVE: To determine if international travel increases the incidence of illness in rugby union players participating in a 16-week tournament. SETTING: 2010 Super 14 Rugby Union tournament. PARTICIPANTS: 259 elite rugby players from eight teams were followed daily over the 16-week competition period (22 676 player-days). ASSESSMENT: Team physicians completed a logbook detailing the daily squad size and illness in any player (system affected, final diagnosis, type and onset of symptoms, training/match days lost and suspected cause) with 100% compliance. Time periods during the tournament were divided as follows: located and playing in the home country before travelling (baseline), located and playing abroad in countries >5 h time zone difference (travel) and located back in the home country following international travel (return). MAIN OUTCOME MEASUREMENT: Incidence of illness (illness per 1000 player-days) during baseline, travel and return. RESULTS: The overall incidence of illness in the cohort was 20.7 (95% CI 18.5 to 23.1). For all teams, the incidence of illness according to location and travelling was significantly higher in the time period following international travel (32.6; 95% CI 19.6 to 53.5) compared with the baseline (15.4; 95% CI 8.7 to 27.0) or after returning to their home country (10.6; 95% CI 6.1 to 18.2). CONCLUSIONS: There is a higher incidence of illness in athletes following international travel to a foreign country that is >5 h time difference and this returns to baseline on return to the home country.

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.

Longer distance races and slower running pace are associated with Exercise associated collapse: SAFER XXV study in 153,208 distance runners.

BACKGROUND: Exercise associated collapse (EAC) is a common medical encounter at distance running events. Risk factors associated with EAC are not well documented. The objective is to determine the overall incidence of EAC and identify risk factors associated with EAC in 21.1-km and 56-km runners. METHODS: A cross-sectional analysis of 153,208 race starters from the Two Oceans Marathon races (2008-2015). All EACs on race day were documented by medical staff. Risk factors associated with EAC investigated included demographics, race distance (21.1 km vs. 56-km), running speed, race experience and race day environmental data (wet-bulb globe temperature [WBGT], humidity, wind speed). Incidence (per 1000 starters; 95% CIs) and incidence ratios (95%CIs) were calculated. RESULTS: The overall incidence of EAC was 1.50 (95% CI: 1.31-1.71). Longer race distance (IR: 2.1; 1.6-2.7; P<0.0001) and slower running speed (IR: 1.3; 1.1-1.5; P=0.0017) were significant risk factors associated with EAC. The incidence of EAC was higher in female vs. male 21.1-km race starters (IR=2.25; 1.47-3.46; P=0.0229). Age and environmental conditions were not associated with EAC (P>0.05) in a cool and temperate environment. CONCLUSIONS: About 1 in 667 race starters (21.1 km and 56-km) develop EAC. Longer race distance, slower running speed and female sex (in 21.1-km starters) are significant risk factors associated with EAC. Race medical directors can identify race entrants that may be at risk of developing EAC, develop prevention strategies and better prepare medical care at these events.

Longer race distance predicts gastrointestinal illness-related medical encounters in 153,208 endurance runner race starters - SAFER XVI.

BACKGROUND: Gastrointestinal illness-related (GITill) medical encounters during distance running range from mild to debilitating. The objective of this study was to identify factors that may predict GITill among 21.1 km and 56 km race starters. METHODS: This is a cross-sectional analysis of data collected prospectively over 8 years at the Two Oceans 56 km and 21.1 km races with 153,208 race starters. GITill encounters requiring medical attention on race day were recorded by medical staff. Risk factors associated with GITill explored in univariate models included: race distance (21.1 km; 56 km), sex, age group, running experience, running speed, and environmental factors (wet-bulb temperature, wind speed and humidity). Incidence (per 100,000 race starters; 95% CI) and incidence ratios (IR) (with 95% CI) are reported. RESULTS: The incidence of GITill encounters was 60 (95%CI: 50-80) (1/1667 race starters). A longer race distance (56 km vs. 21.1 km) was the strongest predictor of GITill (IR=4.3; 95% CI: 2.7-6.7) (P<0.0001). Among the 56 km race starters, slower running speed (km/h) was a predictor of GITill (IR=1.63; 95%CI:1.2-2.3) (P=0.0024). Neither age group, nor running experience or any environmental factors (wet-bulb temperature, wind speed, humidity) were associated with a higher risk of GITill. CONCLUSIONS: Medical teams, responsible for care at longer race distances, can expect a higher incidence of GITill that require medical attention compared with shorter race distances. Slower runners competing in ultramarathons are a subgroup at higher risk of GITill. These data can assist medical teams at events to improve and plan medical care, target runner education and establish prevention strategies to reduce GITill in runners.