Training in the Heat

Due to the effects of global warming, the world has been gradually heating up, resulting in many places around the world reaching record-high temperatures well above 90+ degrees Fahrenheit. This trend of rising temperatures poses a question to athletes: how will they continue training in these unbearable conditions?

Dangers of training in the Heat:

While heat can just seem like a dreadful factor to push through while training, neglecting the impact of it on the body can lead to potentially harmful consequences. Some athletes may not have the best heat perception and can easily push their bodies too far, leading to heat exhaustion and even heatstroke. Heat exhaustion is caused by dehydration while overexerting the body in a hot environment. This results in a failure to regulate body temperature which will lead to diminished physical performance due to nausea, muscle weakness/cramping, and rapid heart rate which can negatively impact endurance. A more severe form of heat exhaustion is heatstroke: the condition where the body stops sweating and loses the ability to regulate its temperature. When a person has heatstroke, their body temperature will rapidly increase to dangerously high levels and can potentially incapacitate them, leading to the damage of various internal organs such as the brain, and possibly death. Such effects of over-exertion in heat can be unnoticeable and easy to ignore until it’s too late.

Homeostasis:

Homeostasis in the human body as a result of temperature changes.

While training in the heat it is important to recognize one of the most important functions of the human body: homeostasis. In biology, homeostasis is defined as the regulation of a system that helps to maintain a stable internal environment. The many systems and metabolic pathways in the body require a stable environment to work efficiently. Enzymes, proteins that help speed and facilitate biological reactions, require a specific pH and temperature to function. In temperatures and pH levels outside of the perfect range, proteins (enzymes in this case) will start to lose their shape, causing them to work less efficiently or stop functioning altogether. When this happens, reactions inside the body that makeup systems like the cardiovascular system will start to fail.

Homeostasis is like a cycle as described in the above picture. For example, when the body is too hot, your blood vessels will dilate, resulting in greater sweating. Sweating results in evaporative cooling: sweat evaporates off the skin, cooling down the body. When you reach a normal temperature, the sweating stops.

Heat Acclimatization:

In order to train safely and be able to compete in hotter environments, athletes need to become acclimated to the heat. As the body is gradually exposed to natural heat, it will develop adaptations to systems that help regulate homeostasis. To acclimatize to the heat, it takes about 2 weeks of daily exposure to heat. When first starting out on this regimen, an athlete should not spend too much time training in the sun. It is good to start with 30 to 60 minutes of exercise in heat daily and gradually build up to 60 to 90 minutes of heat exposure per day over the span of a few weeks. Athletes should be especially wary of how their body feels as they train in the heat. Overexertion and heat-induced illnesses can come out of nowhere to unsuspecting athletes. It is also important to drink lots of water before, during, and after training as the goal is to encourage the body to sweat more to regulate body temperature. Sweating is one of the most important mechanisms in regulating body temperature and requires a ready supply of fluid in the body in order to function. The body can lose weight from just sweating during exercise so it is important to replenish the fluids in your body.

The effect of heat acclimatization is that athletes will be able to exercise more comfortably in the heat. Bodily systems will function more efficiently in hot environments due to the body developing adaptations in homeostasis (e.i. Runners having a lower heart rate and perceived exertion at the same pace and temperature compared to before acclimatization). The blood vessels dilate quickly in heat, resulting in more sweat production. It is important to realize that heat acclimatization helps you train more effectively in the heat but at the cost of having to drink a greater amount of water. Water and electrolytes are what fuel the process of sweating and they cannot be neglected. Heat acclimatization doesn’t mean you can drink less water; it is quite the opposite.

It takes 2 to 3 weeks for someone to adapt to the heat, but it only takes about a week without consistent heat exposure for an athlete to start losing the heat acclimation adaptations. After three weeks of minimal heat exposure, the body will return to baseline levels of heat acclimation.

Conclusion:

Training in the heat is a dreadful idea to many athletes, but when it becomes necessary, it is important to remember not to do too much too soon. Heat acclimation takes time and doing excess amounts of heat training to begin will have adverse effects.

Sources:

Gatorade Sports Science Institute. “Heat Acclimatization to Improve Athletic Performance in Warm-Hot Environments.” Gatorade Sports Science Institute, 2016, www.gssiweb.org/sports-science-exchange/article/sse-153-heat-acclimatization-to-improve-athletic-performance-in-warm-hot-environments. ‌Accessed 17 Aug. 2024. ‌

Hutchinson, Alex. “How to Run in the Heat like the Pros.” Outside Online, Outside Online, 19 June 2024, www.outsideonline.com/health/training-performance/running-in-the-heat/. Accessed 17 Aug. 2024. ‌

Mosley, Philip. “Why Heat Training Works.” TrainingPeaks, 24 July 2020, www.trainingpeaks.com/blog/why-heat-training-works/. ‌Accessed 17 Aug. 2024. ‌

Nandi, Jathan. “Heat-Related Injuries.” The Mending Playbook, 2 Jan. 2024, www.themendingplaybook.org/physical-injuries/heat-injuries?rq=dehydration. Accessed 17 Aug. 2024. ‌

“Heat Acclimatization.” Heat Acclimatization - an Overview | ScienceDirect Topics, Science Direct, www.sciencedirect.com/topics/medicine-and-dentistry/heat-acclimatization#:~:text=Heat%20adaptation%2C%20often%20referred%20to,and%20skin%20temperatures%20from%20either. Accessed 17 Aug. 2024.

“Heat Stress: Acclimatization.” DEPARTMENT OF HEALTH AND HUMAN SERVICES, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 2017.

https://www.cdc.gov/niosh/mining/userfiles/works/pdfs/2017-124.pdf

“Homeostasis.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 29 July 2024, www.britannica.com/science/homeostasis.