Medical Advice
RUNNING IN THE HEAT
Some simple tips for running in the hot, humid weather: The first is obvious – don’t run in hot, humid weather. As temperature and humidity increase it is wise to run when the sun is down and the heat of the day has not set in. Early mornings are best as the heat of the day can linger into the evening and even into the post-sundown times.
Slow down not only when it warms up but before it gets too warm as well. If you know the later parts of your run will be in higher temperatures ease back early and allow your body to run at a lower stress level. Much like an engine, if you run it too hard it will overheat. If you drive it nice and steady it will purr along. Even at temperatures as low as 65 degrees the body begins to have difficulty dissipating heat over prolonged periods of work such as distance running. The energy costs associated with the heat buildup amplifies as the humidity and temperature of the environment go up.
Wear loose fitting wicking material to allow evaporation of moisture from the skin. This provides our natural air-conditioning system (sweating) to have its intended effect of cooling the body. Other materials such as cotton soak up the sweat and hold it in making the evaporation-cooling mechanism ineffective.
Wear light colored clothing. This will reflect some of the light keeping the clothing and your body somewhat cooler. Dark colors will absorb the light causing it to heat and act like an oven around the body.
Pour cold water over your head and neck. One of the areas of greatest heat dissipation is the head. Tremendous amounts of blood pump through your head (via our neck, of course) every minute. As your body heats up so does the blood traveling around your body. To cool the blood in its most abundant arena, and hence cooling the blood traveling throughout your body, you can simply pour cool water on your head and neck. If you have never done this on a long warm run try it. It feels great!!
Wear a hat (optional). One concern of wearing a hat is that it has the potential to hold heat around your head unless it is able to “breathe”. There are hats made of wicking material and there are hats with venting systems that are designed for running. The advantage of wearing a hat, specifically one with a wide brim, is that it provides a shading effect from the sun. Direct sunlight can make a difference in feel of 15 degrees over the ambient temperature and heats the skin. This shading effect discounts the increases in temperature of the direct sunlight on the head, neck and face while also providing some protection from sunburn.
Run in the shade. If the sun is out and pounding down seek out shady areas to avoid the direct sunlight. The warmth of the direct sun will affect everything from the road you are running on and the shirt you are wearing to you own skin. Once again, the shading of the area will limit the amount of temperature gain on both you and the environment you are running in. Having run in the shade-less oven known as the Utah desert I can attest to the virtues of running in the shade.
Wear waterproof sunscreen. This provides a defensive measure for the skin from the sun while still allowing the cooling mechanisms of the body to dissipate heat.
Be sure you are drinking adequate fluids. If you have been training on a regular basis you should have an idea of your required fluid intake. On warmer days you will need to adjust this and consume slightly more than usual due to the greater speed in which the body will utilize the body’s fluid stores for various functions. Cooling (sweating) being the most significant of these functions in hot weather. If performing more than an hour of activity consuming sports drinks and other nutrient rich materials (gels, fruit, etc) is important for maintaining the body’s energy stores and electrolyte balances that are needed for optimal participation. Water is an excellent replenisher but over prolonged periods it is necessary to balance fluid intake with electrolyte intake.
Consume cool fluids. Cool fluids provide several advantages. First they provide a direct cooling effect as they are consumed. You can always feel that first drink of cool water going down your throat after/during high level activity. This is a direct cooling effect similar to dumping cool water on your head. The second advantage cool fluids provide is rapid stomach emptying. Not only does this get the sloshing, full sensation out of your stomach quickly but it also allows your body to utilize the fluids rapidly.
Finally, acclimate your body to the temperature you will be running in. Whenever possible acclimate your body gradually to the conditions. This can be a challenge in a Wisconsin spring as temperatures are known to fluctuate but a gradual acclimation to higher temperatures will allow your body to adjust and have greater success with running on warmer days. If possible, this should be done over a period of a few weeks throughout the spring. Adjusting the time of day for training runs in gradually warming temperatures allows the body to have an easy transition to the warmer late spring climate. If the temperature does make a significant jump as it has been known to do, slow down, wear appropriate clothing, drink appropriate beverages, use cooling/sun-avoiding strategies, wear sun screen and, if necessary, take a break from running that day. There are always more days to run.
Heat Illnesses
Being aware of the signs of heat illnesses can be the difference between simply stepping out of a race to being taken away in an ambulance. It is important that you know these signs both for your own benefit and for the benefit of those you are running with. Often it is fellow runners that first happen upon an ill participant and it is the recognition of the runner or runners that there is a significant problem that initiates a life saving medical response. There have been a number of athletic events in the Madison area where one competitor saved the life of another competitor.
Heat Cramps
While generally not life threatening and often a limiting factor prior to a life threatening condition setting in, heat cramps are an indicator that the body has entered a troubled territory. While a single cramp or cramps with significant time in-between them often will not stop a runner from continuing, multiple cramps in a short period of time or cramps occurring in multiple areas of the body are significant warning signs for the runner that their body is in distress. Caused by fluid loss and mineral imbalances in the body, once heat cramps begin runners will be unable to replenish their water and mineral supplies sufficiently to continue. Heat cramps can be very painful and for those who experience heat cramps throughout their body they can be quite frightening. To have no control over the muscles of your body, to have your body rigid with spasming muscles, and to have all of these contracted muscles crying in pain is not a pleasant experience. If you are experiencing cramps in short succession or in multiple locations you should consider ceasing your run, drinking sports drinks, cooling your body, and possibly visiting with one of the medical staff.
Heat Exhaustion
This is a condition far more serious than heat cramps. If treated early and appropriately it is usually manageable. If left untreated it can progress to heat stroke and become life-threatening. Symptoms of heat exhaustion can be heavy sweating, nausea, confusion, vomiting, goose bumps, extreme fatigue, uncoordination (a weaving, staggering runner), and weak and rapid pulse. This person should stop running, be brought to a cool location away from the sun, have medical attention sought immediately (if medical attention is not there in a short time call 911), have any excess clothing removed, be provided cool fluids, and provided any means of cooling the body (ice or damp cloth to the neck, armpits and groin area).
Heat Stroke
This is a life threatening illness. Essentially the heat regulation system of the body breaks down and loses the inability to cool the body. If the body’s temperature continues to rise the heat generated by the body will cause internal organ damage. The brain and organs of the body are only able to function appropriately within a certain temperature limits. Once the body breaches these limits the odds that significant damage could result increases.
The symptoms of heat stoke include those of heat exhaustion but may include bizarre behavior, significant confusion, lack of consciousness, a strong and fast pulse, red skin, either heavy sweating or a cessation of sweating, and a rapidly rising core temperature or a temperature greater than 104 degrees. This condition requires that medical attention must be summoned immediately. Any means necessary should be utilized to cool the individual’s temperature such as cool water immersion (placed in a tub of water or similar), being moved to a cool and shady area, removal of clothing, and ice bags to the neck, arm pits, groin. If the person is conscious and able, have them drink cool liquids. Medical professionals will provide them with intravenous fluids and transport them to a medical facility for further care. The earlier someone with these difficulties is assisted the better their results will be.
Hyponatremia
While technically not a heat illness it is a problem that many runners face that mimics heat illnesses. Hyponatremia, however, is distinctly different in that it is caused by too much fluid in the body or, more accurately, an imbalance of fluid and sodium within the body. As runners participate in an event they will lose their fluid and sodium stores through various means (primarily sweating). Runners who provide their body with water replacement and do not provide appropriate sodium replacement have the possibility of causing this imbalance. As an example: Pretend you are mixing a glass of a powdered drink. You have a glass of water and a package of the powdered mix. You pour the powdered mix into the glass of water and mix it dissolving the mix into the water. Now pour out half of the glass of the fluid causing some of the water and some of the mixture to be removed. Now fill the glass to the top by adding more water but do not add more powdered mix. There is now too much water for the mixture to taste appropriate. This is what is occurring when you only replenish your body with water and not balancing the water intake with sodium. Generally this happens in runners who:
Are participating in events of approximately 4 hours or greater
Drink excessive amounts water
Do not provide their body with appropriate sodium input
Although this generally occurs in athletes participating for 4 hours or greater it can potentially happen to any runner. Symptoms of hyponatremia include nausea, muscle cramping, slurred speech, uncoordination, and disorientation. This is a difficult condition to identify as different from heat exhaustion without checking the athlete’s temperature and use of other more sophisticated medical testing. This illness does require medical attention just as heat exhaustion does so the appropriate course of action is to summon medical providers to the athlete’s location. Prevention of this condition is simple:
During your training determine how much fluid you require per hour while you run (see recommendations elsewhere on this web page)
With events lasting one hour or greater consume sports beverages and small food products along with water to maintain sodium/fluid balance
Increase your sodium intake slightly in the days prior to a long run (if you have high blood pressure or other conditions limiting sodium levels consult with your physician first)
Discuss with a nutritionist your regular daily diet to ensure appropriate intake of sodium and other important minerals and nutrients.
Often runners and their fellow participants are the first line of defense against severe medical conditions. Be aware of what your body is telling you and be aware of how those around you are doing. As with most tasks in life, develop a plan, practice it, and adjust it accordingly. When race day arrives you will reap the rewards of this planning.
