Heat Acclimatization to Improve Athletic Performance in Warm-Hot Weather
This week’s article covers homeostasis and the constancy of the internal environment. Several natural phenomena can override even the most stable dynamic system. One of those phenomena is heat, particularly warm-hot weather. Homeostatic mechanisms are built in as control systems, allowing negative and positive feedback signals to either reduce the intensity of an affect and completely eliminate it, or to enhance an affect. The natural mechanisms to protect against excessive heat are thermoregulation and sweating. However, continuous heat can quickly overpower the ability of the body to regulate heat. That is why heat acclimatization is an important homeostatic modification to our ability to regulate heat.
At first heat exposure will cause high physiological strain, elevating the core temperature and heart rate. Improvements in a hot climate come from daily exercise during the first week of exposure. Improvements in heart rate, skin and core temperatures, and sweat rate are achieved during this period. When given sufficient time to adapt, access to shade, and adequate water, many healthy persons can tolerate extended periods of exposure to heat stress. Important variables involved in the amount of heat stress tolerable is the intensity, duration, frequency, and number of heat exposures, physical work rate, and clothing. The aim of heat acclimatization is a biological adjustment that reduces the negative effects of heat stress.
Heart rate reduction is achieved almost completely by day seven, while seven to fourteen days are required for full heat acclimatization. In order to fully acclimate, one should expose themselves to about 90 minutes of heat while performing aerobic exercise. Whether athletic endeavors or exposure to heat, the duration should gradually increase every day. Not surprisingly, acclimatization to exercising in the heat is sooner for those who are already in shape. Practicing in simulated environments close to the competition environment will optimize performance. Building up to the required intensity, heat, and duration should be considered. The biological adaptations that are present after acclimatization is complete are integrated thermoregulation, fluid-electrolyte balance, and stable metabolic-molecular responses to exercise.
Heat Acclimatization to Improve Athletic Performance in Warm-Hot Weather (2015)