Beware of the HEAT: Outdoor Exercise By Leigh Anne Richards

Beware of the HEAT: Outdoor Exercise

The dog days of summer are here, and it is hot! In the South, we get to also experience high humidity which can lead to heat related exertional illnesses. Understanding warm/hot weather definitions is very important for people who exercise outside during this time of year. Of the many relevant heat related definitions, the heat index is one of the most important. Heat related illnesses range from mild (heat rash, heat cramps), to life threatening heat stroke. Anyone is susceptible to heat related exertional illnesses. It is very important that the exerciser understand the presentation of signs and symptoms associated with these heat related illnesses.

The following are some terms that are necessary to know and understand if you exercise outside in the heat and humidity. Many people are opting to take their exercise outdoors rather than inside a gym or health club because of the lurking virus. Beware of the heat!!

• Heat index: It is the combination of heat and humidity that gives a description of how the temperature feels. It is not actual air temperature. When the heat index is over 90 degrees Fahrenheit, extreme caution should be considered before exercising outdoors. • Heat cramps: They are associated with excessive sweating during exercise and heat exhaustion Fitness over Fifty is to immediately stop the activity by Leigh Anne Richards and hydrate with chilled water and/ or an electrolyte replacement sport drink. The are usually caused from dehydration, exerciser should electrolyte loss, and inadequate blood be cleared by a doctor before resuming flow to the peripheral muscles. They strenuous outdoor activities. usually occur in the hamstrings, calves and • Heat stroke (Hyperthermia): This is a quadriceps. Treatment for heat cramps life- threatening condition in which the is rehydration with an electrolyte (salt) body’s thermal regulatory mechanism is solution and muscle stretch. overwhelmed. Key signs of heat stroke • Heat syncope: This results from physical are hot skin, pale or ashen colored skin, exertion in a hot environment. In an high pulse rate, high respiratory rate, effort to increase heat loss, the skin and decreased urine output and a core blood vessels dilate to such an extent temperature (taken rectally) over 104- or that blood flow to the brain is reduced 105-degrees Fahrenheit. Is to move the causing symptoms of headache, dizziness, person to a cool area and reduce the body faintness, increased heart rate, nausea, temperature immediately, Get immediate vomiting, restlessness, and even possibly medical attention. If immediate medical a loss of consciousness. Treatment is to attention is not possible or available, sit or lie down in a cool environment with immerse the person in a cool bath while elevation of the feet. Hydration is very covering the extremities with cool wet important as well. cloths and massaging the extremities to • Heat exhaustion: This is a shock like propel the cooled blood back into the condition that occurs when excessive core. sweating causes dehydration and • Exercise Induced Hypotremia (water electrolyte loss. A person with heat intoxication): This is most associated exhaustion may be pale and clammy, have with prolonged exertion during sustained, a rapid or weak pulse, loss of coordination, high intensity endurance activities decreased performance, dilated pupils, such as marathons or triathlons. It is and profuse sweating. Treatment for attributable to excess free water intake,

which fails to replenish the sometimes-massive sodium losses that result from sweating. Symptoms of hypotremia can vary from light headedness, malaise, nausea, altered mental status. Risk factors include hot weather, female athletes/exercisers, poor performance, and possibly the use of nonsteroidal antiinflammatory medications. Treatment advises exercisers to drink only as much fluid as they lose during sweating.

According to the Center for Disease Control (CDC) about 300 Americans die every year of heat related illness. Most of these deaths can be avoided if people better understand the dangers. Everyone is at risk if he or she does not stay hydrated, but there are certain people who are at a greater risk: • Those who are active, exercise, or spend a lot of time outside. • Elderly people. • People with chronic illnesses who are taking certain medicines. • People who are severely obese. • Outdoor workers such as construction workers. • Athletes who train outside in the heat • People with low cardiac reserve whose hearts are unable to quickly adjust to the changes the body goes through in extreme heat. Patients with heart failure should not exercise in the very hot and humid weather. Their hearts have less reserve capacity to transport heat from the body and their hearts can become overworked.

It is very important for the body to sweat. Up to 60% of the human body is water and only about 10% of this water is in the bloodstream. A lot of water in the bloodstream can be lost through sweating. In fact, during very hot and humid conditions, we can sweat up to 3 liters, which is almost all of the water in our bloodstream. To replace the water that is lost from the bloodstream, the body takes water from its tissues or uses the fluids that you drink during exercise. In humid conditions, the body tries to cool itself by sweating even more. If you do not replenish the water that is lost, you will become dehydrated.

Here are some tips for elderly people or chronically ill patients for patients to handle the summer heat and humidity while exercising

• Continue your usual exercise habits but move indoor to a cool, air-conditioned space. Try walking on an indoor track. It is easier to walk with a mask indoors on a track than run the risk of heat stroke outside. Check out local locations for indoor tracks. • Weigh yourself before you exercise or exert yourself outside. If your weight drops more than 2 or 3 pounds from your usual “dry weight”, call your Dr. to see if your medicines may need adjusting • Be cautious and take frequent cooling breaks if you must be outside.

Summer weather does not have to sideline your exercise regimen. The above suggestions can help you plan and understand ways to modify your routines to exercise safely.

Sources: Exercising in Hot Weather, Fit for Duty Fit for Life. U.S. Public Health Service Commissioned Corps. Medicinenet.com- Hyperthermia: A Hot Weather Hazard for Older People Hot Weather Exercise Tips, Texas Heart Institute Information Center Leigh Anne Richards, MEd, Certified Personal Trainer, Group Exercise Instructor, General Manager- MetroFitness. For any questions or comments, contact Leigh Anne at LAMetrofit@aol.com