Martin Schwellnus

University of Pretoria | UP · Sport, Exercise Medicine and Lifestyle Institute (SEMLI)

Objective To determine the incidence of acute respiratory illness (ARill) in athletes and by method of diagnosis, anatomical classification, ages, levels of performance and seasons. Design Systematic review and meta-analysis. Data sources Electronic databases: PubMed-Medline, EbscoHost and Web of Science. Eligibility criteria Original research a...

Objective To review risk factors associated with acute respiratory illness (ARill) in athletes, including non-infectious ARill and suspected or confirmed acute respiratory infections (ARinf). Design Systematic review. Data sources Electronic databases: PubMed-Medline, EbscoHost and Web of Science. Eligibility criteria Original research articles...

Acute respiratory illness (ARill) is common and threatens the health of athletes. ARill in athletes forms a significant component of the work of Sport and Exercise Medicine (SEM) clinicians. The aim of this consensus is to provide the SEM clinician with an overview and practical clinical approach to non-infective ARill in athletes. The Internationa...

Acute illnesses affecting the respiratory tract are common and form a significant component of the work of Sport and Exercise Medicine (SEM) clinicians. Acute respiratory illness (ARill) can broadly be classified as non-infective ARill and acute respiratory infections (ARinf). The aim of this consensus is to provide the SEM clinician with an overvi...

Purpose: To determine factors predictive of prolonged return to training (RTT) in athletes with recent SARS-CoV-2 infection. Methods: Cross-sectional descriptive study. Athletes not vaccinated against COVID-19 (n = 207) with confirmed SARS-CoV-2 infection (predominantly ancestral virus and beta-variant) completed an online survey detailing the f...

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 physic...

Background Research evidence is commonly compiled into expert-agreed consensus statements or guidelines, with an increasing trend towards their publication in peer-reviewed journals. Prominent among these has been the publication of several International Olympic Committee (IOC) tatements to help inform sport and exercise medicine (SEM) practice. Th...

Objectives Research evidence is commonly compiled into expert-informed consensus guidelines intended to consolidate and distribute sports medicine knowledge. Between 2003 and 2018, 27 International Olympic Committee (IOC) consensus statements were produced. This study explored the policy and practice impact of the IOC Statements on athlete health a...

Objectives: Currently there are five international screening tools that are recommended to identify individuals who require pre-exercise medical clearance to reduce the risk of medical encounters during exercise. Therefore, the aim was to determine the percentage of race entrants who are advised to obtain pre-exercise medical clearance and the obs...

Objectives To compare the performance of various diagnostic bronchoprovocation tests (BPT) in the assessment of lower airway dysfunction (LAD) in athletes and inform best clinical practice. Design Systematic review with sensitivity and specificity meta-analyses. Data sources PubMed, EBSCOhost and Web of Science (1 January 1990–31 December 2021)....

Objective: To determine independent risk factors associated with a history of exercise-associated muscle cramps (hEAMCs) in distance runner race entrants in a community-based mass participation event. Design: Cross-sectional study. Setting: 2012 to 2015, Two Oceans marathon races (21.1 and 56 km), South Africa. Participants: Seventy six thou...

Objective To describe the incidence and burden of illness at the Tokyo 2020 Paralympic Games, which was organised with strict COVID-19 countermeasures. Methods Daily illnesses were recorded via the web-based injury and illness surveillance system (teams with their own medical staff; n=81), and local polyclinic services (teams without their own med...

Objective To describe the epidemiology of injuries at the Tokyo 2020 Paralympic Games, including injuries sustained in the new sports of badminton and taekwondo. Methods Injury data were obtained daily via the established web-based injury and illness surveillance system (WEB-IISS; 81 countries, 3836 athletes) and local organising committee medical...

Objective: Patellofemoral pain (PFP) is a common cycling-related injury, and independent factors need to be identified to enable effective injury prevention strategies. We aim to determine factors associated with PFP in cyclists entering mass community-based events. Design: Cross-sectional study. Setting: 2016-2020 Cape Town Cycle Tour. Parti...

The paper introduces the Healthy Environments for Athletes field campaign to measure environmental conditions (heat stress and allergenic agents) associated with endurance events.

Objective Gradual onset injuries (GOIs) in recreational cyclists are common but not well described. The aim of this study is to describe the clinical characteristics of GOIs (main anatomical regions, specific anatomical sites, specific GOIs, tissue type, severity of GOIs, and treatment modalities) of GOIs among entrants participating in a community...

Exertional Syncope In A Athlete With Recent SARS-Cov-2 Infection - Endurance Sport: Author Block: Marcel Jooste, Martin Schwellnus, FACSM. University of Pretoria, Pretoria, South Africa. HISTORY: A 53-year-old competitive masters endurance athlete presented for return to sport clearance 20 days following SARS-CoV-2 infection. During acute phase,...

Objective To describe the incidence and transmission of SARS-CoV-2 infections in South African professional rugby union players in different phases of return-to-competition during a pandemic. Design Prospective cohort study. Methods Players reported their history of SARS-CoV-2 infection before / during a national competition, using an online ques...

Acute respiratory infections (ARinf) are common in athletes, but their effects on exercise and sports performance remain unclear. This systematic review aimed to determine the acute (short-term) and longer-term effects of ARinf, including SARS-CoV-2 infection, on exercise and sports performance outcomes in athletes. Data sources searched included P...

Background There are limited data on the medical encounters (MEs) occurring during mass community-based running events of shorter distances (10-21.1 km). The aim of this study was to determine the incidence and nature of MEs during the largest mass participation running event in the Netherlands. Hypothesis We hypothesize that the incidence and nat...

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 21.1km and 56km runners. Methods: A cross-sectional analysis of 153208 race...

Objectives The aim of this study is to review the evidence available suggesting that environmental conditions represent a risk factor associated with non-infective acute respiratory illness in athletes. Design Systematic review. Methods PubMed, EBSCOhost and Web of Science (1st January 1990–31 July 2020) were searched systematically using keyword...

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...

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 (21.1km and 56km). Design Cross-sectional study Setting 2012 to 2015 Two Oceans Maratho...

Objective: To determine if scientifically based social network (Facebook) lifestyle interventions reduce 10-year cardiovascular disease (CVD) risk. Methods: Financial sector employees (n = 300) were equally randomly assigned: Facebook plus Health Professionals (FB+HP), Facebook (FB), or control (C). We report changes in 10-year Framingham risk s...

Objective To determine the days until return to sport (RTS) after acute respiratory illness (ARill), frequency of time loss after ARill resulting in >1 day lost from training/competition, and symptom duration (days) of ARill in athletes. Design Systematic review and meta-analysis. Data sources PubMed, EBSCOhost, Web of Science, January 1990–July...

Objective: To determine whether the lifetime prevalence and clinical characteristics of exercise-associated muscle cramping (EAMC) differ between runners entering a 21.1- versus 56-km road race. Design: Cross-sectional study. Setting: The 2012 to 2015 Two Oceans Marathon races (21.1 and 56 km), South Africa. Participants: Participants were c...

Objectives To determine the prevalence of self-reported pre-race chronic medical conditions and allergies in ultramarathon race entrants and to explore if these are associated with an increased risk of race-day medical encounters (MEs). Methods Data from two voluntary open-ended pre-race medical screening questions (Q1 – history of allergies; Q2 -...

Objective There are limited data on factors that predict an increased risk of multiple injuries among distance runners. The objective of this study is to determine risk factors that are predictive of individual runners with a high annual multiple injury risk (MIR). Methods A retrospective, cross-sectional study at 4 annual (2012–2015) Two Oceans 2...

Background Race starting time is often staggered over several hours in large mass-participation endurance sports events. Athlete exposure to environmental conditions changes as wet-bulb-globe-temperature (WBGT) changes during race day. Slower participants may be exposed to changing environmental conditions for a longer duration. In most studies env...

Background The IOC Sports Medical and Scientific Commission has supported the development and dissemination of sports medicine consensus statements for athlete health. Evidence on the relevance and dissemination of these statements is important for the development of future statements. Objective The objective of this project was to investigate the...

Background The International Olympic Committee (IOC) Medical and Scientific Commission has a goal to provide guidance on athlete health for sports organisations. One strategy to meet this goal has been the development and publication of sports medicine consensus statements. It is currently unknown if there has been use of the consensus statements o...

Background There is a high incidence of medical encounters (MEs) in ultramarathon road running races but risk factors associated with MEs in events have not been well investigated. Objective To determine the independent risk factors for all medical encounters in a 90km ultramarathon running race. Design Retrospective clinical audit, cross-section...

Background Risk factors associated with overuse injuries in cyclists (OICs) in recreational cyclists have not been well-studied. Objective To determine risk factors associated with OICs in recreational cyclists participating in a mass community-based cycling event. Design Cross-sectional study. Setting Cape Town Cycle Tour (CTCT) 2016. Patients...

Background One of the goals of the International Olympic Committee (IOC) Medical and Scientific Commission is to provide guidance in relation to injury prevention and the protection of athlete health. One way of meeting this goal is the development and dissemination of sports medicine consensus statements. It is not known if, or how, these consensu...

Background There have been 27 consensus statements published under the International Olympic Committee (IOC) Medical and Scientific Commission with a goal of contributing to the mission of injury prevention and protection of athlete health. The success of these statements in achieving this goal has not been evaluated. Knowledge management (KM) cons...

Background Injury-related medical encounters (injMEs) are common in mass community-based participation cycling events, but there are limited data on the risk factors associated with injuries in endurance cycling events. Objective To determine the risk factors associated with injMEs in a mass community-based endurance cycling event. Design Retrosp...

Background Netball is a fast action game and there is growing interest in the sport. The Netball World Cup (NWC) is an international netball world championship, contested every four years, with 16 teams qualifying by ranking and play-offs. Research on netball injuries is however limited. Objective To determine the incidence and severity of injurie...

Background The IOC Medical and Scientific commission’s mission is to provide a guiding reference for sports organisations on issues relating to the protection of the health of athletes. One strategy to achieve this mission is through supporting the development of consensus statements. Objective This study investigates the relevance and disseminati...

Background Pre-race medical screening at endurance events has recently been suggested, but there are limited data on the use of pre-race questionnaire data to predict adverse events (defined as medical encounters or not finishing a race). Objective To determine if risk factors, that are identified from a pre-race medical screening questionnaire, a...

Background Serious/life-threatening medical encounters (sltMEs) occur during mass community-based events, with higher incidences in ultra-endurance events. Risk factors associated with sltMEs are under-investigated. Objective To determine independent risk factors for serious/life-threatening MEs in a 90 km ultramarathon running event. Design Retr...

Background Illness-related medical encounters (illMEs) are common in mass community-based participation cycling events, but there are limited data on risk factors associated with illMEs in endurance cycling events. Objective To determine the independent risk factors associated with illMEs in a mass community-based endurance cycling event. Design...

Background Running experience and training may be risk factors for exercise associated muscle cramping (EAMC). However, multiple experience and training variables are inter-dependent. A latent class variable may be used to test associations between multiple experience and training variables and EAMC. Objective Is there an association between EAMC...

Background Recent data indicate that pre-race medical screening and education can reduce medical encounters (MEs) at an endurance running event. However, the relationship between the risk of MEs and specific risk factors from pre-race medical screening, together with race day factors, and has not been explored. Objective To determine the independe...

Background The international Netball World Cup (NWC) is contested every four years and 16 teams qualify to participate, based on their world ranking. The risk, nature and severity of illness at the NWC is not known. Objective To determine the incidence, severity and reporting of illness by players during the NWC in 2019. Design Prospective study,...

Background Medical encounters in mass-participation community-based cycling events are not uncommon and may be related to underlying chronic disease or risk factors for chronic disease in race participants. Objective To describe the prevalence of medical conditions, including cardiovascular disease (CVD) risk factors, amongst participants in a mas...

Objective To report the prevalence of lower airway dysfunction in athletes and highlight risk factors and susceptible groups. Design Systematic review and meta-analysis. Data sources PubMed, EBSCOhost and Web of Science (1 January 1990 to 31 July 2020). Eligibility criteria Original full-text studies, including male or female athletes/physically...

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 m...

Exercise-associated muscle cramps (EAMC) are common and frustrating for athletes and the physically active. We critically-appraised the EAMC literature to provide evidence-based treatment and prevention recommendations. While the pathophysiology of EAMC appears controversial, recent evidence suggests EAMC are due to a confluence of unique intrinsic...

Protection of the health of the athlete is required for high level sporting performance. Acute respiratory illness is the leading cause of illness and can compromise training and competition in athletes. To date the focus on respiratory health in athletes has largely been on acute upper respiratory infections and asthma / exercise induced bronchoco...

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 his...

Objective: To determine if repeat annual health risk assessments (RAHRAs) with intervention reduce 10-year cardiovascular disease (CVD) risk in financial sector employees. Methods: Retrospective analysis from RAHRAs in 13737 employees over 4-years. We report changes in 10-year Framingham risk score (FRS) for CVD (%) and risk factors after 1 (GR1...

Objectives To document incidence rate and severity of specific sub-categories of respiratory tract illness (RTill) in rugby players during the Super Rugby tournament. Design Cross-sectional study. Methods Team physicians completed daily illness logs in 537 professional male rugby players from South African teams participating in the Super Rugby U...

Background Netball is a physical game with sudden changes of direction, decelerations, jumping and landing, stop/start manoeuvres and restrictive footwork rules exposing players to injury. Close contact play and shared facilities during tournaments, increase illness risk. Objective To describe the incidence, period prevalence, types and severity o...

Objective: To determine the incidence and nature of illness-related medical encounters (MEs) at a 90-km, ultramarathon, mass, community-based, endurance running event. Design: Retrospective, descriptive epidemiological study. Setting: Comrades Marathon (90 km), South Africa. Participants: One lakh three thousand one hundred thirty-one race s...

Background: Limited data support pre-race 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 (56km) race starters who completed a pre-rac...

In 2020, the IOC proposed a universal methodology for the recording and reporting of data for injury and illness in sport. Para sport is played by individuals with impairment, and they have a unique set of considerations not captured by these recommendations. Therefore, the aim of this addendum to IOC consensus statement was to guide the Para sport...

Background There are no data relating symptoms of an acute respiratory illness (ARI) in general, and COVID-19 specifically, to return to play (RTP). Objective To determine if ARI symptoms are associated with more prolonged RTP, and if days to RTP and symptoms (number, type, duration and severity) differ in athletes with COVID-19 versus athletes wi...

Background: Gastrointestinal illness-related (GITill) medical encounters during distance running range from mild to debilitating. The objective is to identify factors that may predict GITill among 21.1km and 56km race starters. Methods: This is a cross-sectional analysis of data collected prospectively over 8 years at the Two Oceans 56km and 21....

Objective To determine the prevalence of chronic prescription medication (CPM) use in distance runners (by age and sex) and to compare CPM use in 21.1km vs. 56km race entrants. Methods A cross-sectional study of 76654 race entrants who completed a pre-race medical screening questionnaire during race registration, which included questions on the us...

Objective: To determine the prevalence of non-communicable disease (NCD) risk factors, total NCD risk category and 10-year risk for cardiovascular diseases (CVD) in financial sector employees. Methods: This descriptive observational cross-sectional analysis, data from 36 074 employees was analysed. NCD risk factor data was obtained from health r...

Objectives: Risk factors related to Gradual onset injuries (GOIs) in cyclists need to be identified to enable effective injury prevention strategies. We aim to determine risk factors related to GOIs in cyclists participating in mass community-based events. Design: Cross-sectional study. Setting: Cape Town Cycle Tour. Participants: Race entra...

Objectives Prevalence, clinical characteristics and severity of gradual onset injuries (GOIs) in cyclists are poorly documented. We determine the prevalence, anatomical regions/sites affected and severity of GOIs among entrants in a community-based mass participation event. Design Cross-sectional study; Setting Cape Town Cycle Tour; Participants...

Objectives Risk factors related to Gradual onset injuries (GOIs) in cyclists need to be identified to enable effective injury prevention strategies. We aim to determine risk factors related to GOIs in cyclists participating in mass community-based events. Design Cross-sectional study. Setting Cape Town Cycle Tour Participants Race entrants (n=35...

Background There are limited data on acute injury-related medical encounters (injuries) in endurance cycling events. Objective To determine the risk factors for injuries during a mass community-based endurance cycling event. Design Retrospective, cross-sectional study. Setting Cape Town Cycle Tour (109 km), South Africa. Participants 102 251 ra...

Purpose: There are limited data on risk factors associated with illness-related medical encounters (illMEs) in cycling events. The aim was to determine risk factors associated with illMEs in mass community-based endurance cycling events. Methods: A retrospective, cross-sectional study in the Cape Town Cycle Tour (109km), South Africa with 102251...

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 predicts AEs during a race. Methods: 29585 participants (Male 71.1%, average age=42.1years; Female 28.9%, average age=40.2years) at the Two Ocea...

Physical inactivity is one of the major modifiable risk factors for non-communicable diseases (NCDs) and universal prescription guidelines for physical activity for all individuals include engaging in >150 min of moderate- to high intensity physical exercise weekly. Participation in mass community-based sporting events including park runs, road rac...

Coding in sports medicine generally uses sports-specific coding systems rather than the International Classification of Diseases (ICD), because of superior applicability to the profile of injury and illness presentations in sport. New categories for coding were agreed on in the ‘International Olympic Committee (IOC) consensus statement: Methods for...

Injury and illness surveillance, and epidemiological studies, are fundamental elements of concerted efforts to protect the health of the athlete. To encourage consistency in the definitions and methodology used, and to enable data across studies to be compared, research groups have published 11 sport-specific or setting-specific consensus statement...

In 2013, the Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC-O) was developed to record the magnitude, symptoms and consequences of overuse injuries in sport. Shortly afterwards, a modified version of the OSTRC-O was developed to capture all types of injuries and illnesses—The Oslo Sports Trauma Research Center Questionnaire...

Background Injury and illness surveillance, and epidemiological studies, are fundamental elements of concerted efforts to protect the health of the athlete. To encourage consistency in the definitions and methodology used, and to enable data across studies to be compared, research groups have published 11 sport- or setting-specific consensus statem...

DOI: https://doi.org/10.17159/2078-516X/2019/v31i1a7466 Introduction: Exercise associated muscle cramping (EAMC) is a common clinical syndrome that requires medical attention during and after endurance running events. The incidence of EAMC during the 90km “Comrades” marathon has not been reported. The aim of this study was to document the incidence...

DOI: https://doi.org/10.17159/2078-516X/2019/v31i1a7466 Introduction: Rugby union is a contact sport resulting in injuries, which may increase the risk of future injury. This study aimed to investigate whether a player who sustained an injury in a previous season, had a higher risk of sustaining an injury in the following season. Methods: A prospe...