Select Page

Trail running might kill you, how to stay alive.

Trail running might kill you, how to stay alive.

This morning I read about the unfortunate death of Mexican runner Arturo Héctor Martínez Rueda during the Ultra Fiord 100-mile mountain race that took place in Patagonia earlier this month. His body was found between two checkpoints, almost halfway along the course. Cause of death is presumed to be hypothermia.

Martínez Rueda is not the first runner to pass away as a direct or indirect result of running. Earlier this year Todd Ragsdale went out for an easy hike/run on his favourite trail. When he didn’t return a search was launched and his body was found in a creek just off the trail, cause of death is still unknown. In 2012 Mica True (Caballo Blanco, as introduced to us in Born to Run) died during a run in the Gila Wilderness, New Mexico. The Autopsy revealed that he was suffering from cardiomyopathy, which had caused his heart to become enlarged and probably caused cardiac arrest.

Reading their stories made me realise that you can die while out running.

The reason most people participate in trail running is because they seek adventure. Adventure is defined as a bold, usually RISKY undertaking of UNCERTAIN OUTCOME.

Whether you’re competing in an extreme desert ultra, like MDS, spending a lone holiday running in the mountains or just going out for an easy run in your favourite nature reserve, there are always risks involved. However, understanding and minimizing the risks that predispose you to injury and illness might increase your life expectancy and even help you recognize symptoms in fellow runners.


Mauro Prosperi got lost during the 1994 Marathon des Sables after a sandstorm blew him off course. Humans can survive without water in hot, desert conditions for 24 hours, before your condition will start to deteriorate, until death ultimately occurs after three days without water. image4Prosperi was able to survive in the desert for 10 days by drinking his own urine, bat blood and succulent juice.

Research has shown us that a certain level of dehydration is normal during long distance events and interesting the fastest endurance athletes lose the most body weight (6-8%) without any ill effects on health or performance. Your chances of developing severe dehydration during a well-supported endurance event are highly unlikely.

Decrease your risk of dehydration:

  • Follow race rules and make sure you carry the required amount of water.
  • Drink according to thirst. Thirst is your body’s built in mechanism that protects you from dehydration. The thirst mechanism is stimulated with a loss of body water between 1.7%-3.5%.
  • The IMMDA hydration guidelines recommend drinking at a rate of 400-800ml/hour and your fluid intake should match your race pace and distance. The longer the distance, the less fluid you should be ingesting per hour.
  • Fluid intake should be adapted for temperature and humidity of the race or training environment.
  • Diarrhoea can increase your risk for dehydration. Make sure you get medical assistance when diarrhoea persists during a race.

Exercise Associated Hyponatremia (EAH)

It is impossible to imagine that you can die from drinking too much water. Excessive fluid intake beyond sweat and renal excretion causes abnormal fluid retention and if left untreated, can lead to kidney failure, respiratory compromise, seizures, cerebral edema (brain swelling) and ultimately death. Early Signs include bloating, nausea, vomiting, headache, confusion, disorientation, delirium and altered level of consciousness.

3 main factors contribute to the development of EAH:AdobeStock_27936049

  • Overhydration with excessive fluid intake before, during and directly after a long distance event.
  • Excessive sodium losses due to sweating.
  • The secretion of AVP (antidiuretic hormone) decreases renal water excretion resulting in water retention.

Diagnosis of EAH is confirmed when blood sodium concentration ([Na+]) is less than 135mmol/L. EAH can be successfully treated with an infusion of Hypertonic (3%) saline solution = a very salty IV.

Decrease your risk:

  • EAH can be avoided by following the guidelines for hydration as mentioned above. Drink according to thirst and no more than 400-800ml/hour.

Ingestion of electrolyte-containing hypotonic fluids (sports drinks) DOES NOT PREVENT the development of EAH if you continue to drink to excess.


Mountain weather can be very difficult to predict, temperatures can range from 35°C at the foot of a mountain and end up dropping below zero once you’re exposed to mist, wind and rain on the summit.AdobeStock_95662865

Normal body temperature is 37°C and the risk of hypothermia becomes very real once your body temperature drops below 35°C. Early signs of hypothermia include shivering, slow shallow breathing, confusion, loss of coordination, stumbling, slow weak pulse, slurred speech and drowsiness. Once body temperature drops below 32°C, shivering will usually stop and below 28°C, there is loss of consciousness.

Decrease your risk:

  • Avoid getting wet when it’s cold. Water conducts heat away from the body 25 times faster than air.
  • Most body heat are lost through the skin (radiation), therefor it becomes crucial to wear appropriate clothing for cold weather running. . There is no such thing as bad weather once you invest in the right gear. Layering helps you regulate temperature and keeps you dry during wet conditions:35466
  1. moisture wicking inner layer
  2. insulating middle layer
  3. wind and rain repellent outer layer

To treat mild hypothermia you should find shelter, add layers, and keep moving to generate heat. Ingest fuel and warm fluids (soup) but avoid caffeine. Runners suffering from severe hypothermia should be wrapped (hypothermia wrap) and given warm sugar water.

Exertional Heatstroke (EHS)

EHS is one of the biggest causes of sudden death in runners who participate in endurance races. EHS can be fatal if not treated promptly and correctly.

The diagnosis of heat stroke is simple: “In a previously healthy individual who collapses when exerting in a hot environment for long periods, and whose rectal temperature is above 40°C, the diagnosis of heat stroke is virtually certain” – Epstein Y. Am J Med Sports 2:143-152, 2000

Treatment involves immersion in ice cold bath of water or application of cold wraps. The core body temperature should fall below 40°C within 60 minutes after collapse ( the golden hour for survival). If the body is unable to cool and core temperature continues to rise it will lead to nausea, vomiting, disorientation, confusion, seizures, coma and ultimately death.

Decrease your risk:

Risk of heat stroke is increased when exercise intensity is highest (more likely in shorter-distance races), in athletes with greater body mass (because they generate more heat than lighter athletes), when environmental temperature and air humidity are high, and especially when there is limited convective cooling. – Tim Noakes, Waterlogged

  • Race at an intensity that matches your fitness level.
  • Heat acclimatization/ adaptation: train in temperatures similar to your race environment.
  • Whole body pre-cooling: immersion in ice bath or ingestion of ice slushies.
  • Wear clothing that allows good ventilation and sweat evaporation for continuous skin cooling.
  • Fill your hydration pack with ice, it will act like a cooling vest until the ice melts.
  • Research also links sleep deprivation to heat stroke.
  • Stay well hydrated as recommended above.

Sudden Cardiac Death (SCD)

Exercise is the single best thing you can do for your health, but being a runner does not guarantee immunity from heart disease. The sudden stress of high intensity technical trail running can trigger a heart attack, if you have an existing heart condition or disease. The risk of sudden cardiac death in runners is in actual fact very low. The best way to protect yourself from a cardiac incident is to undergo annual heart health screenings (from age 20) to determine risk and diagnose any cardiac abnormalities.

Hypertrophic Cardiomyopathy (HCM)AdobeStock_40906736 [Converted]

HCM is a thickening of the heart muscle and the most common leading cause of sudden cardiac arrest in athletes. Those with HCM often have a severe thickening of the left ventricle of the heart. The thickened heart muscle makes it harder for the heart to pump blood, causing shortness of breath, chest pain and problems with the heart’s electrical system. HCM is a genetic defect that affects one in 500 people and often goes undetected because many people experience no symptoms and lead normal lives without any heart complications. The first symptom of HCM is often sudden cardiac death.

Coronary Artery disease (CAD)AdobeStock_80507896 [Converted]

CAD is the leading cause of sudden cardiac death in older runners (>35). CAD develops when cholesterol plaque builds up in the blood vessels that supply your heart. Narrowing of the coronary arteries results in decreased blood flow to the heart causing chest pain and shortness of breath. Heart attack occurs when there is significant blockage and blood flow obstruction.

 Decrease your risk:

  • Know your family history of heart disease.
  • Never ignore chest pain or shortness of breath.
  • Partake in regular medical screenings and health checks.
  • Use the heart disease risk calculator to find out your risk of cardiovascular disease.


Stéphane Brosse, close friend and mentor of Kilian Jornet died in 2012 in the Mont Blanc massif when a snow cornice collapsed under him, resulting in him falling 700m to his death. Accidents do happen. Safety always comes first; avoid ledges and overhangs if you are unsure of their stability and use ropes and chains where indicated.

Lightning:12909451_10153984809296217_1904490353202553305_oOn a recent holiday in the Karoo, my husband and I set out on cloudless morning for a run. Our goal was to climb the highest peak on the farm before turning back. Approaching from the south side of the mountain we didn’t see the storm approaching from the north until we found ourselves close to the summit already. We calculated that we could still reach the summit, the highest peak for kilometers, take a few photos, race down, climb back over a 3m game fence and outrun the storm over the vast expanse of an open Karoo veld without any shelter. And you recon, hey I am wearing rubber soled shoes! When I read more about lightning I realized how stupid we were…

Decrease your risk:

  • Your chances of being struck by lightning in South Africa are estimated to be 1 in 350,000.
  • If you are caught in the open, seek shelter in a building.
  • Avoid hilltops, fences, telephone or power lines and steel structures such as pylons and windmills.
  • Do not shelter under lone trees or in isolated sheds.

Rubber-soled shoes provide NO protection from lightning.

Read more about lightning myths here.

Animal attacks

The most dangerous will probably be snake encounters. Snakebites kill 20 000 people worldwide each year. In my own experience, just back the hell away as quickly as AdobeStock_88932975possible and find a way around. This is Africa so when running in nature reserves, ask if there are any predators on the reserve, should you still decide to run amongst lions, that is your choice. Never underestimate the wrath of a female animal with a baby; I’ve been chased by before by impala, zebra and ostriches and when it comes to animal selfies, don’t be that guy!

Crime and Assault

I don’t even want to write about this, but it is a reality. My favourite nature reserve, where it was always safe to run alone, has recently been plagued by attacks; assaults and robberies on trail runners, mountain bikers and hikers. Enough said. Run in groups and go sign the petition! Read more about staying safe on the trails here.

I always believed that life is life and death is death and when it’s your day, it’s your day. So as long as adventure is still out there, you will find me on the trails, while praying my mother doesn’t read this post.

Stay safe out there!


Tarrin van Niekerk

Physiotherapist and Blogger at Running Clinic & UltraRunner ZA
I am a Physiotherapist with a special interest in running injury prevention.I enjoy running in all its forms; but I am happiest in the mountains.I believe in empowering runners by teaching them self-management and injury-prevention strategies. You have all the answers as to why you have pain, I just know how to ask the right questions.I am a fan of common sense and the best current available evidence.

You can find me at:
071 685 2235
Practice: Lifestyle Management Park
Unit 4, Second Floor, Suite 224
Clifton Ave, Lyttelton, Centurion
012 664 6128

Latest posts by Tarrin van Niekerk (see all)

About The Author

I am a Physiotherapist with a special interest in running injury prevention. I enjoy running in all its forms; but I am happiest in the mountains. I believe in empowering runners by teaching them self-management and injury-prevention strategies. You have all the answers as to why you have pain, I just know how to ask the right questions. I am a fan of common sense and the best current available evidence. You can find me at: 071 685 2235 Practice: Lifestyle Management Park Unit 4, Second Floor, Suite 224 Clifton Ave, Lyttelton, Centurion 012 664 6128

1 Comment

  1. Excellent post and research…will share it with my Active Friends in the Middle East…May you always do what you are afraid to do….Your Mother!


Leave a reply

Your email address will not be published. Required fields are marked *


Recent Tweets



Pin It on Pinterest

Share This

Share this post with your running friends!