Running during the hot days of summer can be a good experience if you prepare yourself for it. Dehydration, melanoma � skin cancers and now hyponatremia, or over hydration, are problems that can be avoided with the proper attention.

There are many options to help prepare you for running in the heat. Two weeks should enable you to adapt.  Start by occasionally adjusting the time you run during the day.  Early morning runs will help you avoid the heat but move a few runs closer to midday or early evening and learn to run while it's hot. This will especially help if you plan to race in hot temperatures.

Plan the heat runs in advance. Choose courses that have places to stop for water or put out your own water bottles. Before you head out, drink a big glass of water. It is your best protection against heat exhaustion. Don't wait until you are thirsty to drink. Pour some over your head as well. The International Marathon Medical Directors Association (IMMDA) issued guidelines last fall that suggest that marathoners should consume 13 to 27 ounces of fluid per hour and not more than that.

Runners rarely suffer from heat stroke because they are better conditioned than most athletes and lighter weight.  But waiting until you are thirsty may put you on your way to heat exhaustion. The first sign of trouble is often leg cramps. Stop, massage them and try drinking an electrolyte drink like Gatorade. If you start feeling dizzy and your breathing grows rapid, you probably have heat exhaustion.

Wear lightweight clothing that breathes or wicks away your sweat. Avoid cotton t-shirts, which will become soaked, heavy and prevent evaporation of your sweat, which is how your body cools itself. A lightweight hat can be helpful as well as sunglasses. Wet clothing can also create chafing and bleeding.  Try using one of the new antifriction products such as BodyGlide before you go out for a run.

Sunlight has a profound effect on the skin, causing premature skin aging, skin cancer, and a host of skin changes. Exposure to ultraviolet light, UVA or UVB, from sunlight accounts for 90% of the symptoms of premature skin aging. There are many good sunscreen products available for people exercising or getting wet from sweat. Childhood sunburns are the most damaging.  Use a sunscreen that has a sun protection factor (SPF) of 15 or higher.

Runner's World editor Amby Burfoot wrote an excellent article on fluid consumption in his July issue. He notes that men on average sweat more than women and need to drink more.  Research shows that caffeinated beverages are diuretics but to the same degree as drinking plain water. So, the more you drink the more trips to the bathroom. According to Burfoot "Hyponatremia means low blood sodium but it's caused by excessive fluid consumption, which lowers the concentration of sodium in the blood. A higher percentage of exercisers suffering from Hyponatremia have been women including deaths in the Boston and Marine Corps Marathons last year." 

For more information on Hypnatremia and exercising in the heat, go to the Gatorade Sports Science Institutes web site at www.gssiweb.com.