A blog by runners. For runners.

Transitioning to summer running


This past weekend it was an unseasonably balmy 85 degrees in my part of the Carolinas. Thankfully, this was a fluke and our weather has since returned to more spring-like temperatures.

But it was just the warning we needed to realize that summer is just around the corner. Which got me thinking about – you guessed it! – summer running.

I’ll be honest, I’m not looking forward to running in 90-degree temps. So, I’ve been looking for ways to make the transition to summer running easier on my body.

Understanding acclimatization
If you’ve ever run on a hot, humid day you know that it comes with challenges and frustration. Your pace slows down, it’s harder to breathe, and you fatigue earlier. The more often you run in hot weather, though, the easier and more comfortable it becomes. This is called heat acclimatization. With repeated exposure, our bodies slowly adapt to the stress of heat.

In general, it takes runners two weeks to acclimatize to hot conditions. That’s two weeks’ worth of workouts lasting about one hour each. Depending upon your fitness level, mileage, personal heat tolerance level, and how hot your climate is, it may take less or more time to get used to exercising in hot weather.

After you’re acclimatized, you’ll be able to tolerate the heat better. On runs, your heart won’t race as fast, your performance will improve, and you’ll sweat earlier and at a faster rate – which is important because sweating cools us off.

Helping your body adjust
Unfortunately, you can’t speed up the heat acclimatization process. But you can take steps to help your body adjust to running in hot weather:

  • Reduce your speed and mileage. While you’re getting acclimatized, keep runs short and slow. If you’re training for a race and can’t abandon you’re training plan, do all speed work and long runs on a treadmill in air conditioning. Note that doing some runs indoors could extend the acclimatization process. 
  • Run during the coolest part of the day. If possible, run during the early morning or evening hours at first, especially if you live in a location where the weather went from winter to summer and skipped spring. Transitioning to hot weather running gradually works best for some runners.
  • Spend time outdoors during the hottest part of the day. Play with your kids, do light yard work, or just sit down and read a book (but don’t forget sunscreen). Being outside in the heat will help you sweat more efficiently, which will be beneficial on runs.
  • Adjust your thermostat if you have a home treadmill. If you have a treadmill, turn off the AC in your home to mimic outdoor conditions. This trick is especially beneficial if you’ve been training in a cool climate but will race in hot conditions.

Keep in mind that heat acclimatization doesn’t last forever. Once you get used to running in the heat, you have to keep running in hot conditions to keep your body used to it. If you take a week or two off, you may need to start re-adjusting again from scratch.

Written by Jen Matz.