Motorcycles, Dehydration and Heat Exhaustion

Motorcyclists love this time of the year. The worst of the summer heat is behind us in most locations and riding hours are plenty. You might think the end of summer is not the time to be concerned about heat exhaustion. Labor Day weekend is our last summer date before fall specials and Halloween candy sales. It's easy to think of the end of summer as the end of heat injury symptoms. Though heat exhaustion usually happens in the hot sunny climates, sports doctors have found there are many other factors that cause unnecessary risk to sports enthusiasts.

The first phase of dehydration will find the sufferer slightly annoyed, dry mouthed and tired. Unless water is consumed, they may develop muscle soreness and fatigue. With the holiday weekend upon us, many don't realize that consuming alcohol coupled with humid temperatures and mild heat can be as dangerous as chopping wood in the middle of the desert.

Prolonged exposure to the elements can be as dehydrating as summer sun. A motorcyclist experiences heat in many variations. Most long distance riders wear clothing with protective armor. Most of the suits have venting, allowing for air flow while riding which does help cool, but not if the air is a hot wind coming at you at 70 mph. In addition to hot wind and sunny skies, riders will feel heat from the road. Hot asphalt doesn't just smell badly, it also throws heat back up on anyone traveling on it. If you're not covered by a box, or car to non-riders, you're getting the heat. In other words, riders experience dehydrating heat from above, from wind blowing past them, and from the road surface. Mix in a body covering and things heat up quickly in mild temperatures.

Most riders take regular pit stops to stretch. Since heat injury will cause a rider to feel thirsty, they will probably find no aversion to drinking water or a sports drink. It's also common for riders to remove helmets and jackets while at rest stops. Sports doctors advise us to learn the difference between heat injury and heat exhaustion. While water and rest will be plenty to recuperate someone experiencing heat injury, heat exhaustion is a different matter altogether.

As our bodies heat up, the heart pumps blood to the outer extremities, cooling the core temperature by transferring heat from the body to the skin. We cool ourselves by sweating. In a humid environment, it's common to experience "futile" sweat. Futile sweat pours from our bodies and drips off because the humid air slows or stops evaporation. Therefore, we sweat and lose precious nutrients without the benefit of our natural cooling system. In dry air, the sweat cools us down, but still costs us nutrients.

Once we stop sweating symptoms escalate quickly. We feel weak and sleepy. Our blood pressure drops, while our pulse escalates. We may feel dizzy. Headaches come on suddenly. Sore muscles bunch and cramp as minerals are depleted. We may develop diarrhea or begin vomiting. At this point, our heart is being taxed and unless immediate hydration begins, we may lose consciousness. Motorcycles and unconscious riders do not belong in the same sentence. However, all of the above is easily treatable.

Experiments during WWII showed that drinking water during prolonged moderate exercise, like walking, would keep a body hydrated and cool if the body consumed as much water as it lost. Unless we consume the amount of fluid we sweat and lose on bathroom breaks, we still risk overheating.

Modern doctors advise athletes to include carbohydrates and sports drinks in their diets. A good sports drink allows intestines to absorb maximum water intake with a little salt. Too much salt can cause vomiting and diarrhea, limiting water absorption. Salt can also be replaced by eating salty food, like potato chips or salty peanuts. In addition to salt, peanuts will replenish protein. Carbohydrate rich foods include whole grains, cereals, fruits and vegetables. Most pit stops provide whole grain crackers, oatmeal cookies, fresh fruit and dried fruit. Trail mix is a great snack choice while riding. However, it gets heavy if you have to be conservative about the amount of weight your bike carries. Most gas stations sell small bags at very reasonable prices.

Unlike heat injury, which can go on for days, heat exhaustion symptoms escalate quickly if not treated. Dehydration can occur in warm, humid environments, as well as, hot dry climates. Consuming soft drinks or alcohol as a way of hydrating actually increases dehydration. People who engage in long periods of exercise, such as long distance motorcycling, must not only consume water regularly, but must also eat carbohydrates regularly. Carbohydrates in the form of fruits, vegetables or cereals provide needed energy sources to muscles. Most roadside stores provide ample inventories of healthy snack food at reasonable prices.

Resources:

"Dehydration," www.webmd.com

"Dehydration Symptoms," mayoclinic.com

"Foods and Fluids for Fitness," Gatorade Sports Science Institute, www.gssiweb.com

"Heat Stroke, Dehydration and Prevention," Gorps Survival Guide, http//gorp.away.com

Holmes, Tawni, RD/LD, PhD, Assistant Professor, Human Environmental Services, University of Central Oklahoma