Living in Florida, we deal with exercising in heat and humidity about 98% of the year. Okay that’s not a real fact, but it feels like it should be about right.. Moving on.. Why is it SO MUCH HARDER to do the same exercises with the same intensity when it’s hot and humid vs. cool and dryer? Let’s find out!!
Humidity
What is humidity, how exactly does humidity affect your internal temperature regulating mechanisms and why is it so potentially dangerous!?
Humidity is the amount of water vapor in the atmosphere. The humidity percentage is based on a 100% scale and a measure of how saturated the air is with water vapor. So a 100% humidity reading means the air is completely saturated with moisture.
To cool itself, your body will release moisture, or “sweat” through your skin. This sweat then evaporates and this process of evaporation is what cools the body.
The higher the humidity percentage, the more moisture is in the air. The more moisture is in the air, the less sweat will evaporate off of your skin. The less sweat evaporates, the harder it is for your body to cool itself. You may sweat and sweat and sweat, but because that sweat isn’t evaporating, you won’t feel any cooler.
If your body temperature isn’t coming down, your body will continue to sweat which means you continue to lose more and more moisture as well as electrolytes that are contained in sweat!! As this whole process continues, you run the risk of not only dehydration and heat cramps, but on the more severe side of things, a heat-related illness such as heat exhaustion and heat stroke!
Dehydration
"Everyone is ALWAYS talking about it, is it really that big of a deal?!
“Blood flow to exercising muscles is significantly reduced with dehydration due to reductions in blood pressure and perfusion pressure. ... Eccentric muscle activity with decreased intracellular water during dehydration has been theorized to lead to structural, contractile, and enzymatic protein denaturation.”(1)
Simply put, nothing in your body can work correctly when your body is dehydrated and any work that is done, puts a greater strain on your body.
It is said that a fluid loss as little as 1-2% of your body mass challenges your body’s cardiovascular mechanisms that come into play with increased body temperature. If you are actively hydrating during activity and while excessive sweating, you may be able to counteract this loss.
So, yes, it IS that big of a deal!
When we understand how things work, we can understand why certain things happen. It is so important, especially as an athlete - whether that’s at the competitive level or the average gym-goer doesn’t matter - to know how to avoid these potentially life threatening effects of heat and humidity. As well, to really understand WHY hydration is pushed so hard, and electrolyte solutions are a huge part of the health and supplement industry.
Also, it’s not just you! It IS harder when it’s hot and humid! You aren’t having an “off” day and you haven’t lost any of your gains. Your body may just be fighting a losing battle of cooling down in which case YOU must know when it’s time to slow down and take the proper steps to help your body out! Yes, yes.. That usually means HYDRATING!!!!
For further reading on hydration, check out this article.
According to the Mayo Clinic,
warning signs to pay attention to are:
Muscle cramps
Nausea or vomiting
Weakness
Fatigue
Headache
Excessive sweating
Dizziness or lightheadedness
Confusion
Irritability
Low blood pressure
Increased heart rate
Visual problems
If you develop any of these symptoms, you must lower your body temperature and get hydrated right away. Stop exercising immediately and get out of the heat. If possible, have someone stay with you who can help monitor your condition.
Heat illnesses include:
Heat cramps. Heat cramps, sometimes called exercise-associated muscle cramps, are painful muscle contractions that can occur with exercise. Affected muscles may feel firm to the touch. You may feel muscle pain or spasms. Your body temperature may be normal.
Heat syncope and exercise-associated collapse Heat syncope is a feeling of lightheadedness or fainting caused by high temperatures, often occurring after standing for a long period of time, or standing quickly after sitting for a long period of time. Exercise-associated collapse is feeling lightheaded or fainting immediately after exercising, and it can occur especially if you immediately stop running and stand after a race or a long run.
Heat exhaustion. With heat exhaustion, your body temperature rises as high as 104 F (40 C), and you may experience nausea, vomiting, weakness, headache, fainting, sweating and cold, clammy skin. If left untreated, heat exhaustion can lead to heatstroke.
Heatstroke. Heatstroke is a life-threatening emergency condition that occurs when your body temperature is greater than 104 F (40 C). Your skin may be dry from lack of sweat, or it may be moist. You may develop confusion, irritability, headache, heart rhythm problems, dizziness, fainting, nausea, vomiting, visual problems and fatigue. You need immediate medical attention to prevent brain damage, organ failure or even death.
References
Cleary, Michelle A, et al. “Dehydration and Symptoms of Delayed-Onset Muscle Soreness in Normothermic Men.” Journal of Athletic Training, National Athletic Trainers Association, 2006, www.ncbi.nlm.nih.gov/pmc/articles/PMC1421497/.
“How to Keep Cool during Hot-Weather Exercise.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 6 May 2017, www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/exercise/art-20048167.
*The resources and links listed are only suggested as sources for further exploration. They do not necessarily imply endorsement.
**Photos may be taken from Google.
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