Summer Heat Issues

Summer running can be so enjoyable, if you can avoid over heating.  The problem is primarily with the radiant effect of the sun.  Finishing your run before the sun gets above the horizon will help you avoid the worst part of the hot effect.  In researching this for my YEAR ROUND PLAN book I collected the following tips that can help you avoid serious problems.  As always, be conservative and stop at any of the warning signs that concern you. 

When you exercise strenuously in even moderate heat (above 60F), you raise core body temperature.  Most beginning runners will see the internal temperature rise above 55F.  This triggers a release of blood into the capillaries of your skin to help cool you down.  This diversion, reduces the blood supply available to your exercising muscles, meaning that you will have less blood and less oxygen delivered to the power source that moves you forward—and less blood to move out the waste products from these work sites.  As the waste builds up in the muscle, you will slow down. 

So the bad news is that in warm weather you are going to feel worse and run slower.  The worse news is that working too hard on a hot day could result in a very serious condition called heat disease.  Make sure that you read the section on this health problem below.  The good news is that you can adapt to these conditions to some extent, as you learn the best time of the day, clothing, and other tricks to keep you cool.  But it is always better to back off or stop running at the first sign that you may be coming into this condition.  The following are proven ways of avoiding heat adversity.

Running workouts during summer heat

1. Run before the sun gets above the horizon.  Get up early during the warm months and you will avoid most of the dramatic stress from the sun.  This is particularly a problem in humid areas.  Early morning is usually the coolest time of the day, also.  Without having to deal with the sun, most runners can gradually adapt to heat.  At the very least, your runs will be more enjoyable than later in the day.  Note: be sure to take care of safety issues.

2. If you must run when the sun is up, pick a shady course.  Shade provides a significant relief in areas of low humidity, and some relief in humid environments.

3. In areas of low humidity, it’s usually cool during the evening and night.  In humid environments there may not be much relief. The coolest time of the day when it’s humid, is just before dawn.

4. Have an indoor facility available.  With treadmills, you can exercise in air conditioning.  If a treadmill bores you, alternate segments of 5-10 minutes—one segment outdoor, and the next indoor.

5. Don’t wear a hat!  You lose most of your body heat through the top of your head.  Covering the head will cause a quicker internal buildup of heat.

6. Wear light clothing, but not cotton.  Many of the new, technical fibers (polypro, coolmax, dri-fit, etc) will move moisture away from your skin, producing a cooling effect.  Cotton soaks up the sweat, making the garment heavier as it sticks to your skin.  This means that you won’t receive as much of a cooling effect as that provided by the tech products.

7. Pour water over your head.  Evaporation not only helps the cooling process—it makes you feel cooler.  This offers a psychological boost which can be huge.  If you can bring along ice water with you, you will feel a lot cooler as you squirt some regularly over the top of your head—using a pop top water bottle.

8. Do your short runs in installments.  It is fine, on a hot day that is scheduled for an easy run, to put in your 30 minutes by doing 10 in the morning, 10 at noon and 10 at night.  The long run, however, should be done at one time.  Speed workouts should also be done all at once, but you may take more rest between speed reps, and you may break up the distance when it’s hot (running twice as many 800’s as one mile repeats).

9. Take a pool break, or a shower chill-down.  During a run, it really helps to take a 2-4 minute dip in a pool or a shower.  Some runners in hot areas run loops around their neighborhood and let the hose run over the head each lap.  The pool is especially helpful in soaking out excess body temperature.  I have run in 97 degree temperatures at our Florida running retreat, breaking up a 5 mile run into 3 x 1.7 mi.  Between each, I take a 2-3 minute “soak break” and get back out there.  It was only at the end of each segment that I got warm again.

10. Sunscreen—a mixed review.  Some runners will need to protect themselves.  Some products, however, produce a coating on the skin, slowing down the perspiration and producing an increase in body temperature buildup.  If you are only in the sun for 30-50 minutes at a time, you may not need to put on sunscreen for cancer protection.  Consult with a dermatologist for your specific needs—or find a product that doesn’t block the pores.

11. Drink 6-8 oz of a sports drink like Accelerade or water, at least every 2 hours, or when thirsty, throughout the day during hot weather.

12. Look at the clothing thermometer on my website or in my books.  Wear loose fitting garments, which have some texture in the fabric.  Texture will limit or prevent the perspiration from causing a clinging and sticking to the skin.

13. When the temperature is above 90F, you have my permission to re-arrange your running shoes—preferably in an air conditioned environment.

Symptoms of Heat Disease:

  • Intense heat build-up in the head
  • General overheating of the body
  • Significant headache
  • Significant nausea
  • General confusion and loss of concentration
  • Loss of muscle control
  • Excessive sweating and then cessation of sweating
  • Clammy skin
  • Excessively rapid breathing
  • Muscle cramps
  • Feeling faint
  • Unusual heart beat or rhythm

Risk factors:

  • Viral or bacterial infection
  • Taking medication—especially cold medicines, diuretics, medicines for diarrhea, antihistamines, atropine, scopolamine, tranquilizers, even cholesterol and blood pressure medications.  Check with your doctor on medication issues—especially when running in hot weather.
  • Dehydration (especially due to alcohol)
  • Severe sunburn
  • Overweight
  • Lack of heat training
  • Exercising more than one is used to
  • Occurrence of heat disease in the past
  • Two or more nights of extreme sleep deprivation
  • Certain medical conditions including high cholesterol, high blood pressure, extreme stress, asthma, diabetes, epilepsy, cardiovascular disease, smoking, or a general lack of fitness
  • Drug use, including alcohol, over-the-counter medications, prescription drugs, etc.  (consult with your doctor about using drugs when you are exercising hard in hot weather).

Take action! Call 911
Use your best judgment, but in most cases anyone who exhibits two or more of the symptoms should get into a cool environment, and get medical attention immediately.  An extremely effective cool off method is to soak towels, sheets or clothing in cool or cold water, and wrap them around the individual.  If ice is available, sprinkle some ice over the wet cloth.