Heat Stress Risks and Exercise Guidelines

Summertime brings a special training and racing caution: heat-stress risks. You want to know what to do before, during and after unusually hot/humid conditions. Know the signs of heat stress, heat exhaustion and heat stroke. It can kill. Know, too, that the higher the heat-index, the slower will be your "racing pace", and that's normal. We're human; we're not super-human.

Our activities are for enhancing our health and fitness, not impairing them or worse. Some macho types think that more suffering in the sun, heat and humidity, even withholding from themselves fluids, is going to toughen them to the conditions. Unless you're training for what you know will be a hot/humid race for which you need to acclimate, avoid training or hard racing in risky conditions.

Factors affecting our risk of heat illness: Metabolic rate: Higher intensity (or speed) of exercise, the higher our core body temperature becomes over time of exercise. That's why short sprint events in hot weather are much less risky than endurance events. One measure of metabolism is heat (calories) expended. Temperature:Environmental temps affect the temperature gradient. Hydration: We must be able to freely perspire to enjoy the cooling effect of evaporation. Dehydration is dangerous! Humidity: Evaporation rate (therefore, cooling rate) is reduced as the relative humidity rises. See more on humidity below. Clothing: Our clothes must not hinder the heat-loss mechanism of radiation. We don't want to stop heat from being transferred from our skin surface to the environment. Fitness: The unfit, and some special populations like children, will not be ready or able to effect the cooling mechanism of adequate perspiration. The obese also will also be less able to enjoy heat-loss, as they wear more naturally insulating adipose tissue like excess clothing. Medical Risks: General effects of aging. Alcohol or other drug abuse. Chronic illness, such as diabetes or blood-vessel disease. Recent illness involving fluid loss from vomiting or diarrhea. Acclimatization: Some of us can train ourselves to be more tolerant of heat, by improving our physiological heat-loss mechanisms.

Next page: > Heat Index and Heat Factors to Consider

source from about.com

Should You Exercise in the Heat?

With much of the country buried under the heavy pall of a heat wave, outdoor exercise has become not only uncomfortable, but downright dangerous. Exercising when it's very hot outside can cause a number of problems. Some are minor - Dehydration, sunburn, heat rash and/or a really crappy workout. Some can turn into major problems like heat exhaustion or heat stroke.

The problem is, we often don't know we're overdoing it until it's too late. If you exercise all the time, you may not think twice about heading outside for your usual workout, not realizing that your body, no matter how fit it is, needs time to adapt to hot weather exercise. A few tips: Watch your heart rate: High temperatures and humidity can send your heart rate soaring. Many of us try to run, walk or cycle at the same pace we normally do, sometimes pushing ourselves even when we're clearly struggling. Wear a heart rate monitor and check your heart rate regularly. If it's very high, you know to back off, cut your workout short or move it indoors. The sweat factor: If you stop sweating, that's a major warning sign that your body can't regulate your temperature and you should stop your workout and head indoors. Look for signs of heat exhaustion: Besides the sweat factor, stop your workout and get indoors if you feel nausea, fatigue, dizziness or so hot that your head might catch on fire. Treating yourself right away (with fluids, a cold shower, an air conditioned room, etc.) can help you avoid heat stroke, which is much more serious and usually requires emergency treatment.

Find more tips for exercising in the heat and be sure to leave a comment about your experiences. Have you ever overdone it in the heat? What did you do about it and how do you take precautions now? Leave a comment and tell us about exercising in the heat.

source from about.com