Exercise and heat

Spring officially begins and we are expected to have high ambient temperatures, which can cause a series of disruptions in the body when performing physical activities, from simple muscle cramps and fatigue to a fatal condition: heat stroke. Although it is preventable, heat stroke affects thousands of people every year. In fact, it is the second leading cause of death among young athletes in the United States.

Athletes with heat exhaustion maintain their ability to reduce heat for a short time, as the compensatory mechanisms for dissipating it fail due to impaired central nervous system function.

Under normal circumstances, body heat dissipates through sweating, breathing and evaporation. When the ambient temperature is above 35 ° C, the evaporation of body heat accounts for practically all heat dissipation because other mechanisms only work when the ambient temperature is lower than the body temperature. However, the efficacy of sweating is limited. Sweat that drips from the skin does not evaporate and does not contribute to cooling. The effectiveness of sweating is also limited by body surface area and moisture.

The body can compensate for large changes in temperature, but prolonged exposure to heat that exceeds the ability to dissipate heat increases the core body temperature, but elevations above 41 ° C denature some proteins, which can lead to shock. In time, it stipulates death. Usually this position is due to strenuous exercise in hot conditions.

Babies are also at great risk because of the larger body surface area relative to their mass, which facilitates their overheating. They are also slower to acclimatize and have a lower thirst response.

Common sense is the best prevention. Avoid vigorous or prolonged physical activities in humid environments and high temperatures. If exercise cannot be avoided in the heat, the evaporation should be facilitated with light clothing or a fan. Maintaining adequate fluid and sodium levels helps prevent heat compensation.

Thirst is a poor indicator of dehydration and the need to replace fluids during exercise because thirst is not stimulated in the early stages of dehydration.

For maximum fluid absorption, drinks that contain sugars are suggested, as the body can absorb them up to 30 percent faster than water. Drinks containing 6 or 7 percent carbohydrate concentration are recommended to facilitate rapid absorption. High carbohydrate concentrations should be avoided as they can cause stomach cramps and delayed absorption. However, in most situations and activities, plain water is suitable for hydration, as it prevents overwatering.

Acclimatization allows people to work safely in temperatures that were previously unbearable or potentially harmful. To achieve the maximum benefit, acclimatization usually requires spending 8-11 days in a hot environment with little exercise daily, which greatly reduces the risk of heat stroke.

It is best to prevent.