Hot Weather Running
The body generates waste heat during heavy exertion, so running in the summer heat is particularly difficult and potentially dangerous. However with proper precautions and some common sense it is possible to continue running through the worst heat waves.
Heat Stroke-Exhaustion
The primary danger of running in hot weather is heat exhaustion or heat stroke. Do not minimize the dangers here. Heat stroke is potentially fatal. Runners should become familiar with the symptoms of and treatments for heat stroke and exhaustion. If you begin to feel these symptoms while running, stop running, rehydrate, and cool off right away.
Take the following precautions to reduce the risk from hot weather running.
Clothing
The ideal attire for hot weather running is a good pair of running shoes and lots of sunscreen. Various laws, customs, and personal modesty prevent most people from running in this attire, but you should wear as little as permitted by your personal modesty and local customs. Wear light weight shorts and shirt. Look for modern light weight or mesh fabrics that are designed for hot weather activity. Wear white. This is not fashion; dark colors absorb more solar energy and are hotter than light colors.
Wear sunscreen. Apply the sunscreen before you dress. Summer weight clothing, especially mesh fabrics, does not effectively block skin cancer causing UV radiation. So you should also wear the sunscreen under your clothing.
When and Where to Run
Don't run in the heat of the day. Run early in the morning or late in the evening as your schedule permits. Get up before dawn if necessary. Run when it is raining, but beware of lightning storms. The rain will cool you.
Try to find a cool place to run. Run on the shady side of the street rather than in direct sunlight. If people are watering their lawns, run through the sprinklers. Run in or to a public park or other location with water fountains.
Adapting
Give your body a week or two to adapt to the heat. If hot weather starts suddenly, do shorter runs until your body adapts to the heat. If the first really hot day of the summer is the day you planned to do your 20 mile run, change your plans.
Dehydration and Fluid Replacement
You will sweat profusely while running in the heat, so you need to make sure you replace the lost fluids and electrolytes. Weigh yourself before and after running. Every two pounds you lose is about a quart of fluid you need to replace. Make sure you replace the fluids, but if weight is an issue, be careful about the calories in beverages. They add up very fast if you must replace several quarts of fluid.
You will also lose electrolytes while sweating, and they must be replaced. Don't use salt tablets however; most people get too much sodium. Other electrolytes such as potassium are more important to replace. You can drink sports drinks and fruit juices in moderation. Also eat potassium rich foods.
To monitor yourself for chronic dehydration, weigh yourself every morning. Rapid weight losses, especially when it is very hot, probably signal chronic dehydration. Drink.
With these precautions, you can continue to run throughout the summer.
