by Coach Rachael

Hello Higher Running Family! The topic of running in the heat is very much on the forefront all around the country and for good reason! Much of our great land is enveloped in various heat waves, bringing in record setting temperatures and general safety concerns for people, animals, and infrastructure. I wanted to create a little article to go hand in hand with a Higher Running YouTube Video about heat training.

Like always, please ask questions or if you have any great hot weather training tips, feel free to share. In the article, we will chat about heat factors and how it affects the body, guidance for how to workout in the heat, what to watch for regarding heat exhaustion, and some tips and tricks for staying cool in this weather. 

Let’s Begin! 

“Oh but it’s a dry heat” “Yeah, so is a fire!” I love the back and forth regarding which heat is worse. Humidity causes the body to work even harder to cool itself while dry heat can really sneak up on you because one may miss cues that they are in fact sweating a lot. Evaporation means I didn’t sweat right?

Before we discuss strategies on how to prepare for heat, lets talk about how the body responds to heat from the aspect of thermal homeostasis and the autonomic nervous system. Don’t worry, we are not going to get too much into the science of this but rather the practical application. 

The warmup is always important for a runner to help prepare oneself for the main portion of their run/workout. From the aspect of heat, it is important to let your heart rate come up gradually. The body is warming up and so is the core temperature. To combat too high of a core temperature the body starts to sweat. Blood flow must be diverted to the skin, and all of this requires a little more work from the cardiovascular system. Therefore, heart rates are usually a little bit higher at a given pace in the summer versus winter. The general autonomic nervous system (without going into to too much scientific detail) is what regulates these physiological and chemical functions. Just like any computer or piece of machinery, a series of instructions takes place and then a response is produced. Basically, the body needs just a little bit of time to compute what it is being asked to do and how best the body would like to maintain its thermal homeostasis. If one warms up too quickly, they risk raising their core temperatures past the rate in which the body perceives the increase in heat. For the data minded folks, this is what leads to heart rates suddenly shooting up in the beginning of runs and the risk of not recovering from that sudden spike. The body is constantly trying to play catch up in already challenging conditions. This is really the main thing I see, from a coaching perspective, that causes runner’s issues in the heat. If the first, say, 15 – 20min of a long run can be spent at a gentle and mildly progressive pace, the body will be just that more prepared for the rest of the run.  

Another aspect to cardiovascular data in running is decoupling. Even with a proper warm up, there is only so long the body can withstand having two demands being placed on it: cooling itself and exerting itself. Decoupling refers to the heart rate graph and a given running pace/effort becoming separated. Imagine a graph in which a heart rate line is staying consistent with a pace but as the body fatigues, imagine the heart rate line trending up (higher) while the pace/effort line stays the same or declines. Some decoupling from heat and/or fatigue is very common and nothing to be too scared of but is one important metric to monitor. Watching for sudden decoupling is very important and this can happen within minutes. 

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Before we move on to tips and tricks for exercising in the heat, let’s review a few symptoms that are indicative of heat fatigue or heat exhaustion. 

-Goosebumps on the skin (usually an early clue)

-Sudden increase in sweating (earlier clue)

-Sudden decrease in or cessation of sweating (this is dangerous)

-Clammy/pale skin (need to stop the activity)

-Dizziness or sudden weakness (need to stop the activity)

Now let’s end this on a positive note! The human body is remarkable and with proper care, we can adapt and train in warm conditions. Hydration is critical and possibly the most talked about point with heat training. Specifically, lets talk about pre-loading of electrolytes. It is important to have a steady supply of electrolytes and probably some glucose to go with it for activities lasting longer than 60min. More studies have come out that suggest the body will sweat a bit more efficiently if it is loaded with salt, optimally, before the exercising takes place. For those who have kidney or high blood pressure issues, it is recommended that you check with your primary care physician before loading up on salt. A strategy is to consume a beverage higher in salt the night before and then again prior to exercising in the heat. I am not sponsored by any nutrition companies so if I recommend a product to explore, it is because I have had success with the product. To help with salt intake, the concentration for hot weather athletes needs to be substantial. 300MG of salt, for example, isn’t going to cut it. Plenty of folks lose 700 – 1500mg per liter of sweat (the range can vary even more). Coach Sandi helped create Unived’s Elite Hydration Mix for this reason. Unived is a great company that shys away from artificial flavors and puts a lot of effort into making a product that is easy to digest. If you would like to try Unived, Coach Sandi has a code: SANDI10 for 10% off. I, personally, consume a lot of LMNT (1000mg of salt per serving) and also occasionally use OSMO Pre-Load (1750mg of salt). I am also not afraid to salt my food. Lastly, it can be fairly easy to have out of balance minerals and vitamins when sweating heavily day in and day out. As a safety net for general health, it is recommended that athletes keep tabs of their blood work. If an athlete has ever had an issue with low mineral levels, anemia, etc., it is not unreasonable to have blood work done four times a year. I have listed below a few nutrition supplements I use. Companies like Athlete Blood Test can even let you know if you’re getting in enough or too much sodium and other electrolytes. I have used Athlete Blood Test for about 3 years and Coach Sandi and Sage also utilize ABT for their needs. Sandi has a code for 15% off: sandi15. 

I hope this helps get you to feel more comfortable running in the heat! As always, please feel free to reach out if you have any questions about heat training or any other training needs, please ask! If you’re interested in learning more or want to be coached by me, you can learn more here:


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