By Manuel Munoz II and Dr. Robert L. Herron |
Temperatures have not been this high in decades. Extreme heat conditions can cause a multitude of negative health outcomes such as heat strokes, hospitalization, and death. Additionally, research has demonstrated that exposure to consistently high temperatures has been linked with increased cardiovascular mortality and morbidity.
Exposure to hot and humid ambient temperatures affects physiological function, especially during physical exertion or exercise. To maintain homeostasis and keep our body temperature in a desirable range, the body will start sweating and circulating more blood to the skin to reduce overall body temperature. Sweat is comprised of mostly water from your blood plasma and when the sweat reaches the skin, the water evaporates causing the cooling effect.
The increased blood flow to the skin is facilitated by a higher cardiac output driven by an increase in heart rate and stroke volume. While these adjustments are paramount to cooling, increases in heart rate and stroke volume require a higher workload on the heart.
Additionally, when someone is unable to replace their sweat loss with fluid intake, their body will slowly dehydrate. Once in a hypohydrated state, there is less blood volume to circulate due to the sweat loss and thus additional strain is put on the heart.
Combined with other issues such as prothrombotic conditions, inflammation, and other risk factors, heat stress during rest or physical activity can be dangerous.
Therefore, we want to encourage everyone to prioritize their safety in the heat. Please monitor local temperatures, be mindful of your fluid intake, and stay active. Some ways you can stay cool outdoors are to wear light clothing, spend time in the shade, and stay hydrated. Additionally, it takes a few weeks to let your body adapt to changes in the seasons. Seek out professional guidance from an exercise professional or registered dietitian if you want to further evaluate your specific hydration needs during exercise or need help designing your training to facilitate heat adaptation for yourself of those you coach.
Manuel Munoz II is a Senior undergraduate student at the University of Montevallo studying Exercise and Nutrition Science from Samson, AL. Manuel is a McNair Scholar and member of the Exercise Science Club at the University of Montevallo and has been recognized for being on the President’s List every year during his time at Montevallo.
Robert L. Herron, Ed.D., NSCA-CSCS*D, ACSM-CEP is an Assistant Professor in the Exercise and Nutrition Science Program at the University of Montevallo. Dr. Herron is a Certified Strength and Conditioning Specialist® with distinction from the National Strength and Conditioning Association (NSCA-CSCS*D®) and a Clinical Exercise Physiologist through the American College of Sports Medicine (ACSM-CEP®). Dr. Herron is a graduate of the United States Sports Academy and serves as a Non-Resident Faculty Member.