Heat Training and Adaptation

As temperatures in Texas creep into the 90s, we wave goodbye to the fantastic training conditions of late fall, winter, and early spring.  Soon, the weather forecast will look the same every day until November:

High: 102
Low: 80
Sunny with 10% of scattered thunderstorms

Everything will turn brown, the ground will crack, and just about every conversation will turn to the topic of how bad we need rain.  As hot as it will be, there is a little silver lining, especially for those of us who are training through the heat of the summer and then heading north to do a fall race.

With heat training comes some adaptations that can really pay off on race day.  You've seen it before.  Remember that first cool day of the fall where you felt like you just dropped the hammer and crushed your workout...and it felt effortless?  Lower temperatures helped, but there were some other factors that played into it.

As your body adapts to heat, it has a better control of body temperature.  You begin to sweat sooner and your body activates more sweat glands, which means you get a jump on cooling and keeps your core temperature down longer.  Additionally, your sweat has a slower transit time, which allows for re-absorption of some electrolytes.  Heat adaptation also increases your blood volume, which means there more blood (oxygen) available to your muscles.  And finally, your heart rate increase while exercising is less than that of someone who is not acclimated.

Even if you aren't headed north for a race, remember as your body adjusts, those hot runs will get easier.  You aren't going to be setting any PRs, but things will start to level off if you follow a few tips.

It takes time for the changes to take place, but some changes can be seen as soon as a few days.  When heat training, you should consume extra fluids and electrolytes.  Also, dial back the intensity of your workouts, especially in the beginning, and know the signs of heat illnesses.  Run in the shade, in the morning or at night.  It will take a minimum of 5-10 runs of an hour to start feeling even a little better.  Cardiovascular adaptations can start happening as quickly as 3-5 days, while sweat rate changes will probably take 10-14 days.

Luckily, for those of us that live here, we do get to train as the seasons change, so we aren't thrust directly into 100 degree heat.  Still, be careful and try to remember, you are building your infrastructure for a successful fall/winter race.