Mass Participation Endurance Events

General Principles

  • This chapter shows the development of an algorithm for the management of 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.


  • Road running

  • Cycling

  • Cross-country skiing

  • Triathlon

  • Wheelchair

  • Swimming

Approach as a “Planned Disaster”

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

  • Mass gatherings always have 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.

  • 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.

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

  • A comprehensive medical plan utilizing 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

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

    • Running (42 km): 0.5% to 20% risk of injury (as defined as requiring a medical encounter)

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

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

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

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

    • Cross-county skiing (55 km): 5%

    • Triathlon (51 km): 2% to 5%

    • Cycling (variable): 5%

  • Variables and unknowns: race day weather, event distance, event type, and condition (health and fitness) and acclimatization of participants

    • Influence of increasing heat and humidity on marathons:

      • Medical encounters increase and race times slow.

      • Race dropouts increase.

      • Increases in exertional heat stroke and exercise associated hyponatremia

    • Heat limits

      • Cancellation at 82°F wet bulb globe temperature (WBGT) is recommended by the American College of Sports Medicine (ACSM) guideline, but this is based on fit and acclimatized participants.

      • Twin Cities Marathon data imply cancelling at WBGT near 70°F may be better for nonelite runner safety and community emergency response load, especially for unac­climatized participants.

      • The cancellation level is likely event specific, but the number of medical encounters and nonfinishers seems to accelerate with WBGTs above 60°F. Elite runners seem to tolerate hotter conditions, and races may elect to run the elite race while cancelling the nonelite race.

      • A WBGT measurement on site is the best course of action, but if not available, WBGT can be calculated using a formula (available at ) based on ambient temperature, relative humidity, time of day, and sky cover. Conversely, enter the ZIP code of the event, the time of day, the cloud conditions, and the sport at .

Anticipating Casualty Types

  • Exercise-associated collapse (EAC) is most common: hyperthermic, normothermic, and hypothermic with normothermic exercise-associated postural hypotension most frequent

  • Low-frequency but potentially fatal medical emergencies can occur, including cardiac arrest, exertional heat stroke, exercise-associated hyponatremia, 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, treatment, transfer); reduce community medical burden. Secondary: prevent overloading of emergency medical services and emergency departments.

Role in Race Operations

  • Event and runner safety

  • Medical decisions

  • Medical spokesperson

  • Executive committee administrative functions

  • Coordinate medical aspects of transfer to “unified central command”

Prevention Strategies


  • Definition: Prevention or reduction in the occurrence of casualties, reducing the severity of casualties

  • Passive: Cooperation of participants not required. Examples: start times, course modifications, traffic control

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

  • Enforced active: Helmets, wetsuits (required)


  • 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

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

  • Maximum time limits 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.

    • Alternatives: alter, postpone, cancellation

    • Publish protocol in advance.

    • Announce risks at start.

  • Some 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 (bomb detonation–Boston, Hurricane Sandy–New York).

  • Impaired competitor policy:

    • Define an approach regarding an athlete who appears ill or injured during the competition, especially concerning 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 as long as they leave and enter the course in the same spot and receive no intravenous fluid. This is especially important for citizen-class (nonelite) runners.

    • Criteria for continuation of event participation: 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?

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

  • New data from of 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 screening and intervention program also included an acute prerace illness check with an educational intervention in 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), nutrition.

    • 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 the banning of 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.


  • Course survey: hills; turns; immovable objects; traffic control; altitude changes; open water (participant safety and environment influences)

  • Start: downhill starts increase risk for wheelchair competitors; wave starts should be employed to relieve congestion and risks associated with falls in mass starts

  • Aid stations

    • Major: full medical care; equipped and staffed for most anticipated problems

    • Minor: comfort care, fluids, first aid, shelter

    • Location: start; every 15 to 20 minutes along course; finish line

    • Rolling aid: vehicle (bus or van) equipped and staffed to deliver medical care for expected injuries along the course; requires an open lane on the race course for the vehicle(s)

    • First-response teams: motorcycles, bikes, golf carts, or gators; 2–3 person teams; automatic defibrillator and first aid

  • Finish area ( Fig. 97.1 )

    • Triage: chute, postchute, and area triage (sweep teams)

    • Field hospital: major aid station (see Fig. 97.1 ). Subdivisions may include triage, intensive medical, intensive trauma, minor medical, minor trauma, skin, and medical records.

    • Ambulance support for ED transfer (see Fig. 97.1 )

    • Shelter for healthy finishers

    • Dry clothes shuttle; consider clothes dryer for wet or cold conditions.

    • Fan out finish line area to spread out participants in hot races.

    • Elevated spotters to identify downed participants in crowded areas (see Fig. 97.1 )

    Figure 97.1

    Finish area of mass participation events.


  • Healthy competitors who abandon the race

    • Prevent new or exacerbation of previous injury by transporting to shelter or reducing repetitive stress: hypothermia, hyponatremia, stress fracture, strain.

    • Examples: vans, buses, golf carts, gators, snowmobiles, snowcats, public transportation, sled, toboggan, boat

  • Ill or injured competitors

    • Prevent progression of illness or injury (both overuse and acute injuries) without increasing individual morbidity or mortality.

    • Access care for more severe acute illness or injury. Minor injury can use transportation for healthy athletes who abandoned. Casualties requiring medical care need transport by ambulance to nearest ED or event medical station.

    • Examples of medically equipped vehicles for ill competitors who abandon: advanced (ALS) or basic (BLS) life support ambulance, life flight helicopter.

    • Finish area

  • Access medical care in finish area.

Jul 19, 2019 | Posted by in SPORT MEDICINE | Comments Off on Mass Participation Endurance Events

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