Is the medical world keeping pace with Mass Participation Amateur Sport?

In their capacity as medics, athletes and spectators, Professor Sanjay Sharma, Michael Walker, and colleagues argue the need for a proactive consensus-based approach to medical standards for Mass Participation Amateur Sport (MPAS).

By Michael Walker 1 BSc (Hons);  Sabiha Gati 2 BSc (Hons), MBBS MRCP (UK), PhD; Mats Borjesson 3 PhD, MD, FESC; Sanjay Sharma 1 BSc (Hons), MD (Lon), FRCP (UK), FESC

(1 )Division of Cardiovascular Sciences, St Georges, University of London,  (2 )St Thomas’ Hospital, Westminster Bridge Road, London (3) Swedish School of Sport and Health Sciences and Karolinska University Hospital, Stockholm, Sweden


Mass Participation Amateur Sport (MPAS) is a contemporary social phenomenon evolving at an unprecedented rate. This is presenting new challenges for associated medics, volunteers, and event organisers. A need now exists for proactive, medical-led consensus on the development and implementation of medical standards across MPAS events. This will enable the medical world to keep pace with change, thus protecting the countless volunteers, medics and participants involved, and increase the sustainability of MPAS.

Serpentine Swim. Photo source:


“WARNING: BLUE GREEN ALGAE” stated the sign. Swimmers, it explained, could suffer from severe skin rashes, eye irritation, vomiting, diarrhoea, fever, and muscle pains.(1) To the multifarious, six-thousand-strong, Lycra-clad body of energy that had congregated over five autumnal days in London’s Hyde Park, such a warning would have seemed inconsequential compared to the endurance test that awaited them.  Gathered from across 84 countries and aged between 16 and 85, this predominantly non-elite field were taking their opportunity to compete on the same course that had created Olympic legends one year before. Upon completion of the cold, chaotic 1500m swim around the Serpentine Lake, participants would, further to the frenzied, inelegant yet essential task of removing their wetsuits, then clamber aboard two wheels and cycle for 80 kilometres. It wouldn’t end there; a 10 kilometre run would now stand between them and the climax of this encounter. Such an experience would push physical and mental pain thresholds to their limits, yet provide each participant with a unique sense of reward, addressing fundamental human needs like self-esteem, fulfilment, pride, and well-being. It would take more than a warning sign to stop them.


Triathlon epitomises the extraordinary, global phenomenon that MPAS has become. USA demographic data shows that last year almost two million individuals finished a triathlon race, representing growth of 60% in just four years.(2) Similarly, triathlon events in the USA rose almost four-fold over the last eight years, and in the same period annual USA Triathlon membership grew from 193 000 to nearly half a million.(2) This growth was seen in microcosm during the World Triathlon Series Grand Final at Hyde Park.(3) Yet organisers of this, the largest event of its kind, swiftly predicted afterwards that “the number of people able to compete in the mass participation races will dramatically increase in 2014”, and “races are open to anyone and welcome people of all fitness levels and from all backgrounds to take up the sport of triathlon”.(4) Such anticipation is demonstrated by the demand across other MPAS events such as cycling. For example, the “Ride London 100” event offers over 15 000 amateur cyclists the opportunity to traverse London’s roads, before tackling a formidable hill range in Surrey, totalling a gruelling 100 miles. Following the event’s inauguration in 2012, the 2013 ballot entry system was oversubscribed by over 30 000 applicants in just 24 hours.(4)

Modern day MPAS events like triathlon and cycling were however little known and seldom competed in when, in 1981, a band of 6255 runners crossed another finish line in London, on Constitution Hill. Euphoria undiminished by heavy rain and the preceding 26.2 miles of suffering, this hardy bunch had just completed the inaugural London Marathon. Almost one million finishers have now conquered this most iconic of road races.(5) Despite its comparatively rich history, growth in road running also shows no signs of abating.  Last year nearly two million finished a half marathon in the US, representing a 400% increase since the year 2000 and superseding the previous decade’s growth rate of 50%.(6) Those interested in running the marathon can now attempt this already uniquely challenging distance across 100 countries,(7) taking in far-reaching outposts like the North Pole and Antarctica. This surely must have been inconceivable even to the forward-thinking masterminds of the London Marathon. What had been anticipated during the early years of the London Marathon however was “a change in the participants, made up very largely of novice runners attached to clubs, many of them (often half) attempting the distance for the first time and expecting a high level of logistical and medical support”.(8) Almost 30 years on this medical-led analysis is as salient as ever.


One ineluctable requirement defines the endurance participant’s ability to continue exercising for extended durations: sustained muscle contraction. This depends itself on the continuous supply and effective utilisation of both oxygen and fuel.(9) Insufficient and non-specific training methods, combined with inadequate nutritional and hydration strategies, and often folly in expectations, inevitably results in many participants failing to achieve the required physiological adaptations, resulting in arrival at the casualty queue.

The ‘MAMIL’ – middle aged man in Lycra – would appear to best characterise the most prevalent MPAS participant. The highest male participation amongst marathon runners in the USA last year came from the 35-44 age range, whilst USA’s triathlon governing body also reported its highest membership being males in their forties,(2) reflecting a shift towards an older age of participant compared to the preceding two decades. Furthermore, participants in veteran MPAS competitions may be getting older and less fit, as highlighted by the increased finishing times for all quartiles of finishers during a 30km Swedish running race.(10)  This age range has a higher incidence of coronary artery disease, something which has been attributed as the most common cause of sudden cardiac arrest and death in male competitive athletes over the age of 35.(11)


Forty five triathlon participants died during races between 2003 and 2011, of which 31 were swim-related. “The more people who participate, the more incidents like this could occur”, concluded the USA Triathlon Investigation team commissioned to inquire into this upsurge.(12)  Various idiosyncrasies can explain this. Blood vessels become constricted by the cold water, which must then circulate high volumes of blood rapidly upon intense activity; this places greater pressure on the heart, as can the pandemonium of the mass swim start. Paradoxically, heart rate is trying to slow to conserve oxygen in response to extended breath-holding and facial wetting, which exacerbates the situation. Participants often lack the opportunity to warm up, with the sudden change from resting state to sprint in only seconds placing an acute load on the heart. These incidents can manifest from previously undiagnosed genetic heart abnormalities like hypertrophic cardiomyopathy (HCM), which predispose the athlete to fatal arrhythmia; the stress of exercise providing the trigger for sudden cardiac arrest (SCA).

Swim-induced pulmonary oedema (SIPE) is a condition that highlights the requirement for a greater appreciation of the changing nature of medical needs brought about through the growth of MPAS. With a reported incidence of 1.4% in triathletes,(13) SIPE is thought to be induced by a combination of chilly water temperatures, tight wetsuits, and the chaotic start of the triathlon. The subsequent increase in pulmonary blood flow and pressure induces capillary blood to leak into lungs causing oxygen deficiency, leading to obvious respiratory distress. Symptoms include shortness of breath, a rattling cough which produces blood-tinged frothy sputum, and a wet sounding crackle in the lungs. In extreme cases SIPE can cause cardiac arrest. The major challenge for the medical team therefore is ensuring swift identification of swim casualties. Prompt rescue must follow, ideally within one minute, and CPR/defibrillation soon after to optimise chances of survival.

Risk of SCA during the marathon would appear to have increased in recent years, with a reported incidence of 1 in 50 000 participants.(14, 15) Of 12 deaths to have occurred in the London Marathon, the most common cause has been coronary artery disease (CAD). Hypertrophic cardiomyopathy, exercise-associated hyponatremia and brain haemorrhage contribute to this total. All but one of those who died was male, most over the age of 40.(16) These findings are consistent with a recent study showing that incidence of SCA amongst marathon runners has increased amongst male participants, in the majority of cases attributable to underlying cardiovascular disease.(17) Furthermore, these higher risk participants tend not to be the experienced, faster (sub three hour) elite or high standard club athlete, nor the slower (four to five hour range) inexperienced participant, but the more experienced middle-aged male ‘MAMIL’ runner trying harder to claw minutes off their time, often in the three to four hour time range.

In 2012 a healthy 30-year-old became the first female fatality to occur during the London Marathon. Suffering a SCA with only a few hundred yards of her race remaining, this sadly followed the trend (converse to triathlon) that shows the final 2km stretch of the marathon to be the most dangerous, accounting for at least 50% of sudden cardiac deaths.(18) A coroner’s verdict cited use of the now banned supplement 1,3-dimethylamylamine, methylhexanamine  (DMAA), which, combined with extreme physical exertion, resulted in acute cardiac failure.(19) Performance-enhancing drugs and supplements are well discussed in the arena of professional sport, however less so in the amateur field. Indeed, recent questionnaire-based research assessing over seven hundred fitness centre users in the USA found that almost one in ten used performance enhancing drugs.(20)


In the context of such a dynamic picture, in terms both of the unique challenges and inexorable growth underway across MPAS, it can be predicted that an increasing number of under-prepared and at-risk participants will place increased demand on future medical provision. As such, a focus on guidance pertaining to the required medical standards is essential. Historically, such guidance has been lacking, often reactive in nature. Although in 2004 an American medical-led consensus on mass participation event management was published,(21) the authors acknowledged it as “general” in nature. Similarly, the British Medical Association produced guidance in 2010 for the doctor attending a sporting event,(22) although this is generic and somewhat diluted by an appropriate focus on medical indemnity for the doctor.

In 2006 an inquiry into medical safety at UK road running races found as many as 24% of all marathons and half marathons had no first-aid service, and the majority had no doctor present.(23) Tragically it took the death of a young participant at the end of the Bath Half Marathon some eight years earlier to trigger these findings, made by the Chief Medical Officer of the sporting body, UK Athletics. Such a shortfall in medical standards inevitably resulted in medically-led recommendations, which came in the form of a best practice guide, incorporating a risk assessment tool for race organisers.(24) Although comprehensive and needs-based, it could be argued that a proactive approach would be to go further and ensure such “minimum recommended” standards become those of an expected and mandatory nature.


With the axioms of medical consensus and need in mind, a position statement on cardiovascular safety at major sports arenas was published by the European Society of Cardiology (ESC) Sports Cardiology section in 2011.(25) Major sporting bodies in football such as Fédération Internationale de Football Association (FIFA) and Union of European Football Associations (UEFA) have since endorsed this guidance, indicating the influence of change that medical consensus can achieve.  Fundamental to the ESC guide is the construction of a “Medical Action Plan” (MAP) for medical teams, focusing on treatment of sudden cardiac arrest and the optimal steps, or “chain of survival”. This approach could be adapted, in conjunction with that of the UK Athletics Best Practice guide, to address the growing demands for race organisers and medical teams across the spectrum of MPAS.

Of importance when transferring these principles should be MPAS event-specific planning that considers variables such as size, nature, environment and participant profile. A first priority would be to maintain critical time to delivery of CPR (<1 min) and defibrillation (<3-5 minutes) across such varied and expansive environments. Secondly, the number and competence of personnel with regards to emergency care, including necessary training (e.g. water safety) must be specified taking into account the MPAS context. Thirdly, the necessary medical equipment and facilities, including transportation and communication requirements must be enforced, involving mobile units capable of providing emergency care across the whole course.


Integration of both the UK Athletics and ESC models offers a potential vision for the proactive development of future MPAS guidance on medical standards. The following steps would help us achieve this:

1. Inception of an international pan-MPAS working collaborative: that includes members with relevant medical and organisational experience of such events, to initially create a current and future framework for the development of MPAS guidance.

2. Development of guidance integrating existing best practice: using tools such as the ESC Medical Action Plan and UK Athletics Best Practice models (in particular the risk assessment element), to provide the founding principles for successful development of new MPAS medical standards.

3. Subsequent endorsement and adoption across major MPAS sporting bodies: such as the International Association of Athletics Federations (IAAF) and International Triathlon Union (ITU) in addition to other international sporting governing bodies, with a further aim of mandatory implementation of guidance wherever reasonable.

4. Creation and subsequent analysis of injury and emergency event registers: across all MPAS event types, to ensure an accurate and objective view of the current and future medical need, and help inform subsequent guidance.


MPAS is a powerful social phenomenon that addresses the fundamental human needs of millions. Initially enticed by the atmosphere of community, identity and purpose that define such gatherings, MPAS participants, volunteers and medics rapidly find themselves deeply rooted into this incredible social niche. We return for more time and time again. Yet, we have reached a time where action must now be taken to protect all those involved, and ensure that ‘Mass Participation Amateur Sport’ does not itself require a warning sign.


• The current dynamic and anticipated growth of Mass Participation Amateur Sport requires a proactive approach to ensure that medical standards keep pace with such change

• Development of consensus-led medical standards across the breadth and depth of Mass Participation Amateur Sport, following the lead taken by the ESC Arena Safety Medical Action Plan (MAP) and the UK Athletics Best Practice Guide can address the existing need for guidance

• Guidance on medical standards will only become meaningful by subsequent adoption and endorsement from major MPAS sporting bodies such as the IAAF and ITU; this must be supported by the development of participant injury and death registers across the sports

• Achieving this type of proactive, needs-based consensus on medical standards will allow us to ensure the protection of participants, medics, volunteers, and the phenomenon itself.


Michael Walker is a Junior Research Fellow in Cardiology at the Department of Cardiovascular Sciences, St. George’s, University of London

Sabiha Gati is a Specialist Registrar in Cardiology at the Guy’s and St Thomas’s NHS Foundation Trust

Mats Borjesson is a Professor in Sports and Consultant Cardiologist at Swedish School of Sport and Health Sciences & Karolinska University Hospital, Stockholm, Sweden

Sanjay Sharma is a Professor of Cardiology and Consultant Cardiologist at the Department of Cardiovascular Sciences, St. George’s, University of London

Contributors and Sources

Professor Sanjay Sharma (SS) has a strong insight into mass participation amateur sport through his roles as Medical Director for the London Marathon, and Medical Director for the International Triathlon Union World Triathlon Series. The latter experience presented new challenges for his medical team, which included MW and SG, and as such proved the inspiration for the article. MW, first author, drew on his experience an elite standard marathon runner, whilst SG undertook her PhD as a Research Fellow in the field of sports cardiology with SS for three years. As lead author for the European Society of Cardiology consensus statement on safety in Arena-based sport, MB was able to offer a relevant view into how such guidance might be transferred into a mass participation environment. MW wrote the first draft; all authors contributed to subsequent revisions.


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