If you’ve continued your usual run schedule the past couple weeks then you know that the heat and humidity have been brutal just about everywhere in the the good ol’ US of A. To try and beat the heat I’ve woken at 3:20am the past three weeks for all of my mid-week runs to try and get my miles at the coolest time of day. Still, at 4am when I start my run the heat and humidity has been just slightly better and it seems that all I’m doing is removing the sun from the equation. While this is a huge help my experience this morning was that of 84 degrees and 85% humidity which is brutal and performance stopping to say the least.

To battle the heat, hydration and recovery are key points to remember. Perhaps a good place to start is to figure out your sweat rate and to figure out how much water you should drink per day so you know the numbers. I am big on knowing your numbers and as I’ve said before, numbers don’t lie. The numbers cut through the emotion, the mental, the physical and the crap! Being armed with your numbers is a great first step toward maximizing your potential.

First up is you daily water intake. Check out the Human Water Requirement Calculator to see how much H2O you should take in per day. My number surprised me. Just be honest with yourself when using the calculator so you’re as accurate as possible. Also, I don’t count sugary drinks or even diet soda toward my intake number. That’s a personal choice and a good way to make myself decide/opt for water instead of a soda or juice. Knowing how much you should drink daily will ensure that you are hydrated throughout the day and ready for your next training session!

Next up is your sweat rate. This will tell you how much you should drink during exercise to stay hydrated. According to Active.com, “An average person sweats between 0.8 to 1.4 liters (roughly 27.4 to 47.3 oz.) per hour during exercise.” The best way to calculate your sweat rate is to weigh yourself sans clothing right before you workout then go workout for an hour without taking in any fluids and ideally without using the restroom during this time. After an hour of exercise weigh yourself again without clothes. The change in weight is the amount of fluids you lost due to exercise. If you are down two pounds then you lost 32oz

Be specific for the type of exercise you do when calculating sweat rate. If you a want a sweat rate for running then you should run for an hour. You SHOULD NOT lift weights for an hour and then expect that sweat rate to be the same for when you go for a run. You’ll sweat more on a run than you will lifting weights in the air conditioned gym.

Speaking of AC, please pay attention to your environment when calculating sweat rate! If you decide to calculate your sweat rate on the treadmill in your air conditioned gym with the two TM fans blowing on you then know that you will sweat more outside on a hot day. Basically, just pay attention to the temperature, humidity and dew point in relationship to human comfort.

Finally, if you are becoming more active and losing weight like me then be sure to recalculate your sweat rate on a regular basis as your body will become more efficient at regulating heat and your performance will increase too so you’ll want to make sure you are drinking enough, but also not over-hydrating…not a big issue in the recent 100+ temps, but still something to consider so you aren’t trying to run with a lot of extra fluid sloshing around in your stomach. Stay hydrated and stay safe on those hot runs!

Happy Training!

Brian