The Western States Endurance Run is one of the most physically challenging events in the world and participation in it presents numerous medical risks, many of which can be extremely serious or on rare occasions fatal.

Participation in this event is at the runner’s own risk. Although Run Management has experienced medical personnel at various points along the course, the inaccessibility of much of the trail may make it difficult or impossible for medical assistance to reach the runner in a timely fashion. Many sections of the trail are accessible only by foot, horse or helicopter. Each runner is encouraged to consult with his or her own personal care physician regarding any physical or medical limitations before attempting the Run.

Runners’ weights will not be taken at check-in or at aid stations during the race. Rather than (potentially inaccurate) weight data, the medical staff will focus on how the runner feels and looks and his or her mental status at each medical aid station.

It is important for each entrant to recognize the potential physical and mental stresses which may evolve from participation in this Run. Runners may be subjected to extremes of heat and cold. They may develop hypothermia, hyperthermia, dehydration, hypoglycemia, hyponatremia, disorientation and mental and physical exhaustion. Run Management and the medical staff strive to work with runners. They will do all they reasonably can to ensure “safe passage” to Auburn, but ultimately runners must understand their own limitations. This is one event where, as Dr. George Sheehan has said, it is better to follow the dictates of your body — not your ambitions! Adequate physical and mental conditioning prior to the Run is mandatory. If you have not been able to prepare properly, do not attempt to run!

Runners should appreciate the risks associated with participation in this event. Actions may have to be taken on your behalf under extreme time constraints and adverse circumstances. We will make reasonable efforts to give assistance whenever possible. Ultimately and primarily you are in charge, and you are likely to be solely responsible for creating your own crisis that we must then respond to. Be careful, be responsible, and do not exceed your own abilities and limitations. IN THE EVENT THAT A RUNNER REQUIRES EMERGENCY EVACUATION BY GROUND or HELICOPTER-AMBULANCE, THE RUNNER ASSUMES ALL FINANCIAL OBLIGATIONS CONNECTED WITH THIS SERVICE. RUN MANAGEMENT IS NOT RESPONSIBLE FOR ANY DEBTS INCURRED.

Some of the main risks of the Run, but certainly not all of them, are listed here. These should be understood and remembered by all runners, before and during the event. Please note that death can result from several of the risk conditions discussed below or from other aspects of participation in the Western States Endurance Run.

1. Renal Shutdown: Cases of renal shutdown (acute renal failure) have been reported in other ultramarathons and have occurred in varying degrees in the Western States Endurance Run. Renal shutdown (known technically as acute kidney injury or AKI) occurs from muscle tissue injury which causes the release of the protein myoglobininto the blood. Myoglobin is cleared from the blood by the kidneys and will look brownish-colored in the urine, but it is also a toxin to the kidneys and can cause acute vasospasm in the small arteries that supply the kidneys leading to AKI as a result of rhabdomyolysis. Appropriate training is key to prevention of AKI from rhabdomyolysis, and adequate hydration is key to both prevention and treatment of AKI, a syndrome which can be worsened by the use of NSAIDs. Three Western States runners have required a series of dialysis treatments, and others have been hospitalized several days with IV fluids to correct partial renal shutdown. While usually reversible in healthy people, AKI may cause permanent impairment of kidney function. IT IS CRUCIAL TO CONTINUE HYDRATING FOR SEVERAL DAYS FOLLOWING THE RUN OR UNTIL THE URINE IS LIGHT YELLOW AND OF NORMAL FREQUENCY. The Terrible Three: WS research has demonstrated that starting the Run with a pre-existing injury, low training miles due to the injury, and masking the injury during the Run using anti-inflammatories such as ibuprofen, could very well earn the runner a trip to the hospital with acute renal failure. The lesson is simple; if you are determined to start the Run with an injury and low training miles, do not attempt to mask the pain with a pill. Let common sense be your guide and stop when your body tells you to stop.
2. Heat Stroke/Hyperthermia: Your muscles produce tremendous amounts of heat when running up and down hill. The faster the pace, the more heat is produced. In addition to the generation of heat from metabolism, environmental heat stress can be significant during the Run. In 1989, radiated heat off the rocks measured at 114 degrees F. Heat stroke can cause death, kidney failure and brain damage. It is important that runners be aware of the symptoms of impending heat injury. These include but are not limited to: nausea, vomiting, headache, dizziness, faintness, irritability, lassitude, confusion, weakness, and rapid heart rate. Impending heat stroke may be preceded by a decrease in sweating and the appearance of goose bumps on the skin, especially over the chest. Heat stroke may progress from minimal symptoms to complete collapse in a very short period of time. A light-colored shirt and cap, particularly if kept wet during the Run, can help. Acclimatization to heat requires approximately two weeks. We recommend training 90 minutes in 90 degree F heat or greater for at least two weeks prior to the Run if at all possible. If signs of heat exhaustion occur, we recommend rapid cooling by applying ice to the groin, neck and armpits.
3. Risks Associated With Low Blood Sodium: Low blood sodium concentrations (hyponatremia) in ultramarathon runners have been associated with severe illness requiring hospitalization and several deaths among participants of shorter events. Generally, those individual who are symptomatic with hyponatremia have been overhydrating. But, hyponatremia may occur with weight gain and weight loss, so weight change is not helpful in making the diagnosis. Because of the release of stored water when you metabolize glycogen stores, you should expect to lose 3-5% of your body weight during the run to maintain appropriate hydration. It is important to note that hyponatremia may in fact worsen after the Run, as unabsorbed fluid in the stomach can be rapidly absorbed once you stop exercising. Signs and symptoms of hyponatremia may include bloating, nausea, vomiting, headache, confusion, incoordination, dizziness and fatigue. If left untreated, hyponatremia may progress to seizures, pulmonary and cerebral edema, coma and death. The best way to avoid developing symptomatic hyponatremia is to not overhydrate. There is no evidence that consuming additional sodium or using electrolyte-containing drinks rather than water is preventative of exercise-induced hyponatremia. If symptoms develop, one needs to assess whether they are due to overhydration. If that is the case, then stop fluid intake until you remove excess fluid through urination. If severe symptoms present, this is a medical emergency. The runner should be treated with intravenous hypertonic saline and transported to a hospital. Since the typical fluid used for intravenous hydration (referred to as normal saline) can exacerbate exercise-associated hyponatremia, we try to avoid such treatment at the Run unless we are certain that the individual is not hyponatremic.
4. Snow Hazards: Snow levels in the high country vary greatly from year to year. Wear shoes with good gripping characteristics, but falling will still be likely. Snow conditions may vary from soft and slushy to rock-hard and icy. Run slowly and with particular care and concentration in the snow. Sun glasses are highly recommended if considerable snow will be encountered.
5. Effects of Cold/Hypothermia: Temperatures may be near zero in the high country and drop into the 40-degree to 50-degree range during the night portion of the Run. Hypothermia is a potentially serious risk, especially at night since one’s energy reserves will have been depleted from 20 or more hours of running. Hypothermia can strike very quickly, particularly when pace slows from exhaustion or injury. The initial warning signs of hypothermia often include lethargy, disorientation and confusion. The runner will feel very cold with uncontrolled shivering and may become confused, unaware of the surroundings, and may possibly be an immediate danger to themself. Staying well-nourished, adequately hydrated and appropriately clothed will help avoid hypothermia. It is important that runners have access to warm clothing through their support crews, drop bags, or both.
6. Wildlife Hazards: Rattlesnakes, bears, mountain lions and other potentially hazardous forms of wildlife live on the course and have surprised runners in the past. Keep alert and be careful where you place your feet and hands, especially at night.
7. Vehicle Hazards: More than 95% of the Western States Endurance Run is run on mountain trails and fire roads which are closed to vehicles. Nevertheless, there are several areas on the course where runners and pacers must be watchful for automobiles. Some of these areas are:
   • Bath Road to Foresthill: This portion of the trail parallels Auburn-Foresthill Road. There is a wide shoulder with trail; run on it.
   • Mosquito Ridge Road: 0.6 miles after leaving the Foresthill Aid Station, the trail crosses Mosquito Ridge Road, which sees heavy traffic. The crossing has good visibility; stop and look both ways!
   • Highway 49: The most dangerous road crossing in the Run is at Highway 49 (93.5 miles into the course). This is also a checkpoint; so there are volunteers and crews available should you require assistance. Traffic is generally heavy. The crossing has good visibility in both directions; once again, stop and look both ways. You will make this crossing at night and in a fatigued condition.
   • Robie Point to the Finish Line: The last 1.3 miles of the course are run on the city streets of Auburn. The streets are residential and traffic is light, but run with caution.
8. Use of Drugs: No drugs of any kind should be taken before, during or immediately after the Run! Many drugs can increase the risk of heat stroke. A partial list of problem drugs includes amphetamines, tranquilizers, and diuretics. It was necessary to remove one entrant from the Run in 1984 because the runner received an injection to help alleviate nausea and vomiting. This runner was at severe risk without realizing it. There is little known about drug reactions with the stress of running 100 miles.
9. Injuries From Falling: Falling is an ever-present danger on the Western States Trail, with potentially serious consequences. Much of the trail is narrow, uneven and rutted.
10. Altitude Sickness: High altitude plus exertion can produce various degrees of high altitude sickness. This has the potential to progress to severe lung and brain swelling, resulting in death but is unlikely to present more than an annoying headache during the limited time you will be at adequate altitudes to cause symptoms. The initial treatment is to seek a lower altitude, which you will naturally be doing on this course.
11. Rhabdomyolysis: It has been found that some degree of muscle cell death in the legs occurs from participation in the Run. The recovery can take several months. This seems to be a bigger problem in runners who have exerted themselves beyond their level of training. Medical analysis of blood samples taken from Western States runners shows that this occurs to some degree in all runners.
12. Overuse Injuries: Obviously, innumerable overuse injuries can occur, especially in the knee and the ankle. Sprains and fractures can easily occur on these rough trails. Blisters have prevented many participants from finishing. See our foot care page for preventative strategies.
13. Common Fatigue: One of the dangers you will encounter is fatigue. Fatigue, combined with the effects of dehydration, hypothermia, hyperthermia, hyponatremia, hypoglycemia, sleep deprivation and other debilitating conditions can produce disorientation and irrationality.
14. Poison Oak: Poison oak can be found in abundance along several sections of the trail, particularly the last 30 miles.
15. Difficulty in Gaining Access to or Locating Injured Participants: Much of the Western States trail is remote and inaccessible by motor vehicle. Accordingly, in spite of the many layers of safety precautions instituted by Run Management (including radio communications, rescue helicopters on standby, foot patrols, mounted search and rescue personnel and other emergency services and medical personnel at many checkpoints), there is absolutely no assurance that aid or rescue assistance will arrive in time to give you effective assistance should you become sick, incapacitated or injured. In previous years, ambulances and other emergency vehicles have experienced difficulties in gaining access over remote roads jammed with crew vehicles, and other delays have resulted.
16. Getting Lost: Although Run Management endeavors to mark the Western States course, it is definitely possible to lose the trail. If you believe at any time that you may not be on the correct trail, do not attempt to find your way cross country. If you are sure of your route, backtrack to where you last saw a trail marker and try to find other markers showing the direction of the trail. If you are unable to find your way, stay where you are! Wandering randomly will likely take you farther from the trail and reduce your chances of being found. If you do become injured, exhausted or ill, STAY ON THE TRAIL. You will be found there either by another runner or the sweeps who stay behind the last runner and have radio communication. If you feel dizzy, disoriented or confused, do not risk falling. Sit or lie down on the trail until you recover or are found. An unconscious runner even a few feet off the trail could be impossible to find until it is too late. If you are assisted by individuals who are not associated with Run Management and you elect to leave the trail, you MUST notify the official at the nearest checkpoint of your decision to withdraw and surrender your official wristband.

Although medical and other personnel will assist you when possible, remember that you are ultimately responsible for your own well-being on the trail. Only you will know how your body and mind feel at any given time. Monitor yourself during the entire Run, and prepare yourself to drop out at the nearest check-point if you find it just isn’t your day. As you continue past each medical checkpoint, be aware of the number of miles to the next one, realizing that getting rescue vehicles into these areas can be difficult, if not impossible. Remember that several of the winners of the Western States have dropped out in some years but have come back to win in others.