Mass Participation Endurance Events

General Principles

  • This chapter develops an algorithm for managing mass participation endurance events.

  • The medical director is the safety and health advocate for athletes who participate in the race.

  • The safety of athletes is the primary purpose of race medical operations.

  • A central medical command structure can improve the efficiency of the medical team, integrate community resources into the medical plan, and reduce response times for emergencies during the event.


  • Road running

  • Cycling

  • Cross-country skiing

  • Triathlon

  • Wheelchair

  • Swimming

Approach as a “Planned Disaster”

  • Participant and volunteer safety is the primary goal of the race and race medical committees.

  • Mass participation events should be approached as a “planned disaster” (potential mass casualty incident), which may adversely affect the community medical delivery system.

  • Mass gatherings always have the potential for medical illness or injury.

  • Potential casualties can occur in two groups of people: participants (a literature review allows estimation of injury type and incidence; individual race experience allows for more accurate estimates) and spectators (often not considered a part of race medical management).

  • Endurance events share common injury and illness risks that must be addressed by medical management teams, but each event will also have a unique injury and illness profile.

  • A comprehensive medical plan using a central command structure will decrease the community medical burden and reduce the potential for emergency room overload.

  • A central command structure can respond to unexpected race-related or race course incidents by drawing on community emergency medical, public safety, and law enforcement assets.

Incidence and Risk

  • Estimating medical encounters is best done with race data.

    • Anticipated number of starters multiplied by encounter incidence; a race with several years of start history will have an average “no show” rate for race registrants.

    • Project needs: staff, supplies, equipment

  • Risk ranges (defined as a medical encounter during or immediately after the event)

    • Running (56 km): 13% risk of injury over 4 years

    • Running (42 km): 0.5%–20% risk of injury

      • Twin Cities Marathon (Minnesota): 0.5%–3% risk of injury (average 1.89% for entrants from 1983 to 1994)

      • Boston Marathon: 1.6%–10% risk of injury (data from recent races only, as the start time was moved from noon to 10 am )

    • Running (≤21 km): 1%–5% for the 11.5-km Falmouth Road Race (Massachusetts), less than 1% severe injury incidence rate; 0.54% for 21-km Two Oceans Marathon (South Africa), with 0.05% serious injury rate

    • Women over age 50 had more medical encounters at Two Oceans Marathon

    • Triathlon (225 km): 15%–35% injury rate, 13%–21% injury rate among Kona Ironman participants from 1995 to 2014

    • Cross-country skiing (55 km): 5%

    • Triathlon (51 km): 2%–5%

    • Cycling (variable): 5%

  • Variables and unknowns: race-day weather, event distance, event type, participant health and fitness, and participant acclimatization to race-day environment

    • Heat and humidity influence on marathon outcomes:

      • Medical encounters and race dropouts increase

      • Race times slower (increase)

      • Exertional heat stroke and exercise-associated hyponatremia (EAH) increase

    • Heat limits

      • Twin Cities Marathon data imply cancelling at wet bulb globe temperature (WBGT) near 70°F (21.1°C) may be better for nonelite runner safety and community emergency system response, especially for unacclimatized participants (early October race, 45 degrees N latitude).

      • The cancellation level is likely specific to each event, but the number of medical encounters and nonfinishers seems to accelerate with WBGTs above 60°F (15.5°C).

      • Elite runners seem to tolerate hotter and more humid conditions (elites are still at greater risk and will be slower); races may elect to run the elite race while cancelling the nonelite race (best done in advance of the event).

      • A WBGT measurement on site is best for event decision-making, but if not available, WBGT can be accessed for a given locale at . WBGT may become a part of local weather reporting and forecasting in the near future.

Anticipating Casualty Types

  • Exercise-associated collapse (EAC) or exercise-associated postural hypotension (EAPH) is most common cause of collapse after an endurance running event. Body temperatures may be hyperthermic, normothermic, or hypothermic.

  • Low-frequency but potentially fatal medical emergencies can occur, including cardiac arrest, exertional heat stroke, EAH, asthma, insulin shock, anaphylaxis (exercise associated or “bee” sting), and high-velocity or impact trauma.

  • Macrotrauma: musculoskeletal (fracture, dislocation, sprains and strains, contusions), vascular (closed, open), head and neck (concussion, intracerebral bleed, fracture–dislocation), and visceral organs (contusions, laceration, rupture)

  • Microtrauma: tendinitis, stress fracture, fasciitis

  • Dermatologic trauma: blisters, abrasions, lacerations

  • Drowning, near-drowning, and swimming-induced pulmonary edema can occur in water-based events.

Race Medical Operations Purpose

  • Prerace: Develop strategies to improve competitor safety and reduce race-related injuries and illnesses.

  • Race day: Primary: stop progression of injury or illness; evaluate casualties (triage, treat, transfer); reduce community medical burden. Secondary: prevent overloading of local emergency medical services and emergency departments.

Role in Race Operations

  • Event and runner safety

  • Medical decision-making

  • Medical spokesperson

  • Executive committee administrative functions

  • Coordinate event transfer to “unified central command” if emergency situation develops

Prevention Strategies


  • Definition: Prevent or reduce medical encounters, reduce severity of casualties

  • Passive: Participant cooperation or decision-making is not required. Examples: start times, course modifications, traffic control

  • Active: Participant cooperation or self-initiated behavior change is required. Examples: education, safety advisories.

  • Enforced active: Require helmets or wetsuits to participate in the event


  • Definition: Early detection of injury or illness; intervention protocols to stop progression

  • Examples: Impaired runner policy; advanced cardiac life support (ACLS), advanced trauma life support (ATLS), or EAC protocol; on-course ambulance; finish line triage


  • Definition: Treatment and rehabilitation of illness or injury

  • Examples: Emergency department transfer, hospital admission, rehabilitation center


Race Scheduling

  • Location (latitude, longitude, and altitude)

  • Season of year (temperature and relative humidity [median, mean, and range])

  • Safest start and finish times (if average high temperature is >60°F [15.5°C], schedule race start for sunrise)

  • Maximum time limit for competitors to remain on course

Competitor Safety

  • Consider the safety of the athlete first and foremost in all race-related decisions.

  • Use the safest start and finish times for both elite and nonelite competitors.

  • Determine hazardous conditions and develop a written race administration plan to simplify decisions on race day.

    • Ensure volunteer and competitor safety.

    • Define heat, cold, traction, wind, wind chill, lightning, and torrential rain race limits.

    • Develop alternatives: alter course, postpone start, cancel event

    • Publish protocol in advance.

    • Announce event risks at start.

  • Local incidents, such as residential or commercial building fires, gas line explosions, train derailments, etc., may require cancellation of the race if the local public safety personnel are called upon to respond, leaving the race “unattended”

  • Natural disasters and terrorist activities can also shut down a race (COVID-19 pandemic, bomb detonation—Boston, Hurricane Sandy—New York)

  • Pandemics—COVID-19 pandemic—affected most 2020 events.

  • Impaired competitor policy:

    • Define an approach regarding an athlete who appears ill or injured during the competition, especially related to fluid balance abnormalities and heat or cold stress.

    • No disqualification for medical evaluation. Most event rules allow medical assessment of athletes who appear ill without automatic disqualification and allow athletes deemed fit to continue participation if they leave and enter the course in the same spot and receive no intravenous (IV) fluid. This is especially important for citizen-class (nonelite) runners.

    • Criteria to continue participating in the event: oriented to person, place, and time; straight line progress toward the finish; good competitive posture; clinically fit appearance

    • Publish policy in advance.

  • Emergency department (ED) notification: notify local EDs of date, time, and duration of event; also estimate numbers and types of possible race casualties.

  • Preparticipation screening

    • Decide whether event should require pre-event medical screening: Will it improve safety of participants? Will it be cost-effective? Will it protect event and volunteer staff from liability or disease transmission?

    • Generally not recommended beyond usual health screening or interventions by the participant’s personal physician based on risk factors and symptoms.

    • COVID-19 or similar infectious disease agents may affect participant safety, and how to effectively assess participants before the event remains to be determined

  • Data from South African distance running races suggest that an online, automated, and individually targeted medical screening and educational intervention program for runners reduces the incidence of medical complications, specifically serious life-threatening cardiovascular complications, during a race. This intervention program also included a prerace acute illness checklist with an educational handout for symptomatic runners.

  • Competitor education: safety measures, risks of participation, fitness level recommended for participation, hydration and overhydration (drink to thirst, knowledge of sweat rate, ingestion of adequate fluid to nearly replace sweat losses without excessive intake), volunteer identification (standard colors, visibility), and nutrition recommendations.

    • Medical information should be registered with smart phone or computer apps designed for race medical care or placed on the back of race bibs and should include training weight, prerace weight, allergies, medications, chronic medical problems, and emergency contact phone number.

    • Medical alert tags should be worn during the race.

  • Child and adolescent participation in endurance events: there are no data to support restricting participation of individuals under the age of 18 years for medical reasons, and children as young as 7 years have completed marathons without reported adverse effects. A motivated child (not parent), who is growing physically, physiologically, psychologically, and socially during training, should be allowed to participate if the race or event does not ban participation for administrative reasons.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here