Triple digit temperatures have settled in for us in the “Valley of the Sun” for the foreseeable future. It will hit 110 on Friday and the expected low during this weekend’s Adrenaline Night Runs will be in the 80’s. With recent news stories of heat related deaths in our local mountain ranges, it’s time to think a bit about heat acclimation and safety when going out for our training runs. Just because it is hot out doesn’t mean we as endurance athletes need to hide in the gym and run on a treadmill, but understanding the effects on the body and how to prepare are important.
I actually find running in the heat to be an enjoyable challenge and a offer up a great training effect. This will be especially important for me come August 3 when I will be taking on the Angeles Crest 100 for the third time. The race was recently moved into the middle of the summer to avoid the peak SoCal fire season in September. The middle section of the race can reach over 100 degrees and traverses through several canyons which see little in the way of air flow to keep runners cool.
Training in the heat is all about slow and steady acclimation, to be approached much in the same way that a mountain climber adjusts to altitude. Gradually increasing the duration and intensity of runs is key. Don’t expect to go out for your typical 20 mile long run in the middle of 110 degree weather and only bring a couple bottles of water. I successfully trained for the heat during past summers and have a few tips for those running in the heat. Remember this is not medical advice, but some general information on heat training. Everyone will respond differently to heat depending on many factors. Above all listen to your own body and the advice of your medical physician when training in the heat.
Ed Ettinghausen and Jon Wog at the Buckeye Endurance Runs which reached 108 for the high
How the Body Cools
The body functions best at a constant core temperature (~98.6 degrees F). When we exercise in the heat our body produces sweat on our skin. The evaporative cooling effect of our sweat is the main source of cooling our core body temperature down. If fluids are not replaced, dehydration may also occur.
How to stay Cool
It may seem counter intuitive, but dumping a bottle of water over your head may be more effective in hot weather than drinking it. I’m by all means not saying “don’t drink water” because that is also critically important, but realize that the mechanism by which our body cools is sweat. If you directly wet your skin or clothing, you can produce this effect immediately without added stress on the body. Several companies now make fabrics specifically designed to produce a cooling effect when wet including Mountain Hardware’s Cool.Q Zero.
When I was pacing at the Badwater Ultramarathon in Death Valley in 2010 for Dominic Grossman and in 2011 for Mark Matyazic, I experienced this first hand. We would use a garden sprayer each mile to keep our clothes and skin wet, simulating sweat. In addition, we used “ice bandannas” (basically a bandanna folded in half and sewn together to create a pouch, then filled with ice in a slit on the top and wrapped around the neck) that kept a constant drip of ice cold water on the back of the neck. You can purchase a commercially made ice pack here. Even in temperatures up to 120 degrees, we felt quite comfortable and almost chilly out on the course.
Michael Arnstein dumping water over his head in the heat of the day at the Javelina Jundred
Benefits of Acclimation
While using the cooling techniques above may help keep your body temperature in check, slowing adjusting to the heat over a period of a couple weeks will be your best protection against heat related illness including heatstroke. Your body will adjust to heat related stresses, sweat more efficiently and at a lower temperature, lose fewer electrolytes, and perform at a lower core temperature for the same effort and intensity over time.
How To Acclimate
Spend time running in progressively warmer temperatures over a period of 7 to 10 days. Be patient and start with about 30 minutes of moderate paced running in the heat Don’t be afraid to reduce your typical training distances when you start. Avoid a sudden jump up to long distances or speed workouts in intense heat as this will put you at greater risk for heat related illness. Bring plenty of water with and experiment with soaking your clothing, skin and head to see how it can cool your body temperature.
Symptoms of Heatstroke
Heatstroke occurs when your core body temperature reaches 105 degrees F. If you begin to feel the following symptoms in yourself or see it in your training partner, stop your exertion immediately and cool off. Get into the shade and cool your head, clothes and neck right away. If left untreated, heatstroke can be fatal. Don’t be afraid to end your run early and take care of yourself if you feel these symptoms coming on:
- Nausea or vomiting (digestion is made harder by running in the heat)
- Weakness (caused by elevated core temperature)
- Headache (unusually painful and intense)
- Dizziness or confusion
- Rapid shallow breathing
In summary, you can best prepare yourself for a safe summer of running in the heat if you embark upon a 7-10 day period of heat acclimation. Back off your miles and reduce your intensity as your body makes the slow transition to adapting to the stresses of heat. Watch for the signs of heat stroke and be prepared with ways to cool your body including carrying extra water, clothes designed to produce a cooling effect and/or and ice bandanna. When properly acclimated, your body will operate at a lower core body temperature for a similar effort and sweat more efficiently (produce more sweat at a lower temperature and lose less electrolytes).
Be safe out there everyone. Don’t be afraid of the heat, be educated and adapt to it.