Physical exercise and ambient temperature

Abstract

The Brazilian Institute of Research and Teaching in Exercise Physiology -IBPEFEX -working with the objective of publishing/disseminating scientific production in the field of Physical Exercise Prescription with parameters in exercise, effort and human physiology, in the field of health, sport, education, and leisure both collectively and individually through the Brazilian Journal of Prescription and Exercise Physiology -RBPFEX -through this issue, it is to publicize the works of authors/researchers who presented their studies/research, for the appreciation of Collaborating with this aim, this editorial on Physical Exercise and Temperature and Environment states that prolonged exposure to a hot environment can, especially for individuals who are not acclimatized to a hot environment, lead to hyperthermia, a situation that poses a challenge to survival, as evidenced by ted by the high rates of morbidity and mortality associated with high temperature waves. According to data from the Centers for Disease Control and Prevention, it is estimated that between 1979 and 2003, hyperthermic shock caused the deaths of more Americans than the combined effects of other natural phenomena, such as hurricanes, lightning, earthquakes, floods and tornadoes A wave of high temperatures in the summer of 2003, in which the average ambient temperature remained, for two weeks, 3.5o C above the average values commonly recorded in the period, caused more than 35,000 deaths in Europe and more than 1,600 in India. However, the number of deaths caused may be much higher, as many survivors succumb to multiple organ failure during the months and years following the event. In Brazil, national data on mortality caused by high temperatures are not yet available, since the Ministry of Health does not include hyperthermic shock (or hyperthermia) in the mortality indicators of the Unified Health System. through autonomic and behavioral adjustments for the production (thermogenesis and tremor) and dissipation of body heat (vasodilation, sweat production, increased surface area exposed to the environment), which allows the maintenance of body temperature in environments with different temperatures. during physical activity, there is a thermoregulatory challenge to maintain internal temperature, since most of the energy transformed by energy metabolism, which increases 3 to 12 times during exercise compared to rest, is released in the form of heat, which, could increase body temperature by 1ºC every 5 minutes, if the thermoregulation mechanisms were not activated. In this way, as the exercise continues, the heat released by metabolism creates an additional challenge to thermal homeostasis and, in situations where the dissipation capacity is lower than the heat production, there is an increase in body temperature, generating a rate of heat accumulation that may lead to a temperature higher than 39ºC during prolonged exercise. In situations of exercise in a hot environment (situation of lower heat dissipation capacity) higher internal temperature, heart rate and subjective perception of effort are observed during exercise of the same intensity, or reduction of physical performance in activities that the individual can regulate the intensity of effort. Strategies and recommendations should be adopted by professionals who prescribe physical exercise in order to minimize the deleterious effects of practicing sports in a hot environment and the main strategy would be acclimatization, but other factors such as the state of hydro atation and the use of body cooling techniques are some ways to try to reduce the effects before, during and after competitions or training in a hot environment. Sincerely,