Exertional Heat Illness during Training and Competition

Abstract

Exertional heat illness can affect athletes during high-intensity or long-duration exercise and result in withdrawal from activity or collapse during or soon after activity. These maladies include exercise associated muscle cramping, heat exhaustion, or exertional heatstroke. While certain individuals are more prone to collapse from exhaustion in the heat (i.e., not acclimatized, using certain medications, dehydrated, or recently ill), exertional heatstroke (EHS) can affect seemingly healthy athletes even when the environment is relatively cool. EHS is defined as a rectal temperature greater than 40 degrees C accompanied by symptoms or signs of organ system failure, most frequently central nervous system dysfunction. Early recognition and rapid cooling can reduce both the morbidity and mortality associated with EHS. The clinical changes associated with EHS can be subtle and easy to miss if coaches, medical personnel, and athletes do not maintain a high level of awareness and monitor at-risk athletes closely. Fatigue and exhaustion during exercise occur more rapidly as heat stress increases and are the most common causes of withdrawal from activity in hot conditions. When athletes collapse from exhaustion in hot conditions, the term heat exhaustion is often applied. In some cases, rectal temperature is the only discernable difference between severe heat exhaustion and EHS in on-site evaluations. Heat exhaustion will generally resolve with symptomatic care and oral fluid support. Exercise associated muscle cramping can occur with exhaustive work in any temperature range, but appears to be more prevalent in hot and humid conditions. Muscle cramping usually responds to rest and replacement of fluid and salt (sodium). Prevention strategies are essential to reducing the incidence of EHS, heat exhaustion, and exercise associated muscle cramping.

Thermoregulatory responses in wheelchair tennis players: a pilot study

“…[7][8][9]18 In able-bodied subjects, exercise intensity is strongly correlated to CBT increases. 3 The similar exercise intensity, match intensity and rating of perceived exertion between both groups suggest that these factors cannot explain the larger CBT rise in the SCI players.…”

“…An elevated core body temperature (CBT) is known to reduce exercise performance or may even pose a threat to any athlete's well-being by progressing to heat illness, and in extreme cases multiorgan failure or even death. [1][2][3] Mediated by local and systemic (that is, neural) pathways, the body's principal thermoregulatory mechanisms in response to an elevated CBT during exercise are cutaneous vasodilatation and active sweat secretion. 4,5 In spinal cord-injured (SCI) individuals, the neural transmission of thermoregulatory signals is interrupted, leading to an inability to vasodilate and sweat below the level of the lesion.…”

Metabolic Heal and Energy Expenditure Estimates of Border Patrol Personnel Obtained using the Factorial Method

“…Therefore, a specific time period of interest needs to be established. Within Table 1 are four time periods: [1] average for the whole work day, [2] peak activity, [3] peak activity lasting at least 15 minutes, and [4] peak activity lasting at least 30 minutes where metabolic heat production was calculated. The difference between "Peak >15 Minutes" or "Peak > 30 Minutes" and "Peak" is that "Peak" could be a burst of activity that created a high watt level that only lasted for a couple of minutes, whereas "Peak > 15 or > 30 Minutes" was the highest level of activity sustained during the day that lasted for at least 15 or 30 minutes respectively.…”

Nota técnica: El estrés por calor ambiental en el fútbol aumenta en superficies sintéticas

“…La fórmula (1) para calcular el WBGT recomendada por el Colegio Americano de Medicina Deportiva en el año 2007 (ACSM por sus siglas en inglés) (Armstrong et al, 2007) es una modificación de la que publicaron Yaglou y Minard 50 años antes (Yaglou & Minard, 1957). Esta fórmula es un promedio ponderado de tres temperaturas ambientales:…”

“…Según la declaración de consenso del ACSM (Armstrong et al, 2007), si el valor de WBGT es superior a 28°C se considera que el riesgo de complicaciones por calor (incluidos el golpe de calor, y el agotamiento por calor) es muy alto.…”