Thursday, August 14, 2008
For optimum health, you should exercise at least 30 minutes most days of the week, according to Dr. Gary Windler, orthopaedic surgeon with South Carolina Sport Medicine and Orthopedic Center and Trident Health System. Summer can be a great time to enjoy the outdoors, but take precautions to not overdo it. Heatstroke and heat exhaustion are very real concerns, but they easily can be avoided. Prepare to Sweat As your body temperature rises above 98.6 degrees, your body will sweat to cool itself. Blood vessels close to the skin open to allow blood to carry heat away from your muscles. Water from your blood escapes through your sweat glands, cooling your body as it evaporates. Humidity in the air slows the evaporation process, so you should help keep your body cool in other ways. Drink water before you exercise, during the activity, and once your workout is complete. About 16 ounces of water before your activity and 10 ounces every 15 to 20 minutes while you play or workout outside is recommended by the Centers for Disease Control and Prevention (www.cdc.gov). For exercise lasting longer than 1 hour, include a sports drink with your fluid replacement. This will help replace electrolytes such as sodium and potassium that are lost in your sweat, as well as providing carbohydrates to refuel your muscles. Drink water or a sports drink after your workout to replace the fluids you lost. Too Darn Hot As temperature and humidity rise, your risk for heat exhaustion and heatstroke also increase. Know the symptoms of each to take action, such as getting out of the heat into a cool environment or seeking medical attention. If you are sweating heavily, heat exhaustion can occur in as fast as 30 minutes. Heat exhaustion is generally characterized by one or more of the following: • cold, clammy skin • dizziness or fainting • heavy sweating • muscle cramps • nausea or vomiting • shallow breathing • weak and rapid pulse Less common but much more serious, heatstroke occurs when your body can no longer cool itself. This is a true emergency requiring immediate medical treatment including rapid cooling using ice packs or immersion in ice-cold water and notification of EMS through the 911 system. Symptoms may include: • confusion and/or unconsciousness • fever • nausea and vomiting • strong and rapid pulse • throbbing headache • warm, dry skin Made in the Shade To exercise more safely this summer, try these suggestions by the American Academy of Orthopaedic Surgeons: • Drink plenty of fluids. • Get in shape before beginning to exercise in hot weather. • Limit outdoor exercise to early morning or late evening, to avoid the hottest part of the day. • Take it slow and at a lower intensity, exercising for longer periods. • Wear loose-fitting, lightweight clothing that allows your body to breathe. Cotton or moisture-wicking fabrics are preferable. A Safer Sipper Water is second to soda as the most popular drink of choice, now that it is as easy to take with you. Using bottles more than once or opting for a reusable water bottle is better for the environment, but may be giving consumers more than they bargained for. By the Numbers Polyethylene terephthalate (PET or PETE) carries the recycle number “1” and is the most common material for soda and water containers. It is safe for a single use. Refilling this bottle can expose you to bacteria and DEHP, a phthalate, that disrupts endocrine function and is a possible carcinogen. High-density polyethylene (HDPE) is durable, ideal for more than one use, and recyclable, carrying recycle number “2.” Low-density polyethylene (LDPE) carries recycle number “4” and is a food-safe plastic used for bags and plastic wrap. Polypropylene (PP) is less recyclable, marked number “5,” but has not been shown to leach chemicals that disrupt the endocrine system or are carcinogenic. Avoid BPA Polycarbonate plastics, recycle number “7,” are used for sports bottles and baby bottles. Containing bisphenol-A (BPA), which is known to disrupt hormones, bottles made of polycarbonate are more prone to leach BPA if heated or if the plastic is worn. DID YOU KNOW? Choose lightweight, porous clothing when working out in hot weather and avoid changing into a dry shirt to stay cool. Evaporation requires wet clothing, so don't change out of those wet clothes while in the heat. If you compete in sports or exercise for longer than one hour, use sports drinks in addition to water to remain properly hydrated. If you don't like the taste of sports drinks, dilute fruit juice with water and add a pinch of salt. You can't judge hydration by how much you sweat. Due to an increased speed of evaporation, you will actually sweat up to 10 times more in a dryer climate than a humid climate, although you will appear to sweat less.