Heat Special: Why Runners Should Train In The Heat

It's time to embrace summer heat as a training tool. Here's how.

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While runners regularly take themselves past their comfort zone in training, everyone seems to whine about how uncomfortable heat makes them. No one has ever improved his or her fitness or racing performance by being comfortable, however; it’s when you’re especially uncomfortable that you start to get a training effect.

Most runners recognize the importance of training in the heat if their goal race is expected to reach temperatures above 75 degrees, which is highly likely if you’re racing within the next three months. The training effect of heat, however, goes beyond acclimating to more of it: Heat creates a training stimulus, like speed, hills, or altitude, that can enhance your fitness and running prowess. Rather than thinking of it as an uncomfortable annoyance, consider it a tool. So, who wants to suffer a little?

Before anyone gets too crazy and collapses from heat exhaustion, we’re not suggesting you push past your limit. Everyone has a different threshold for heat, so please know where your line is before you cross it. Some signs you’ve passed uncomfortable and are approaching heat exhaustion: You’re sweating heavily but your skin feels cold and clammy, even with goosebumps; you feel weak, dizzy or faint; you have a headache or nausea. Any of these symptoms means it is no time to be tough but to back off, stop and get cool. But there’s room to explore the training effect of heat before you get to that stage.

Training Effect

Numerous studies have shown that training in heated conditions, two to three times per week for 20 to 90 minutes, can produce a multitude of beneficial training effects. These include:

  • Lower core temperature at the onset of sweating
  • Increased plasma volume (Plasma is the liquid component in your blood. If the volume is increased, you can send blood to cool your skin without compromising the supply carrying oxygen to your muscles.)
  • Decreased heart rate
  • Increased oxygen consumption
  • Improved exercise economy

The result? You can run faster and/or more efficiently in all temperatures.


Be hydrated! You want to feel the effects of the heat and have it supplement your training, but you need to go into it well-hydrated. Drink water generously, letting thirst be your guide, all the time, but particularly when the weather transitions and you need to adapt. If you’re looping a route, doing hill repeats or are training at the track, bring a water bottle and a bag of ice with you.

Also dress appropriately if you’re heat-training outside. The best running outfit includes a light-colored cap, mesh or light material tee or tank, light-colored and lightweight shorts, sunscreen and sunglasses.

The Workouts

Steady and Warm: Get out in the heat and just run. If Mother Nature isn’t supplying the heat you need, run on a treadmill in a room where the temperature is 75-85 degrees. Keep your pace moderate and only run a distance you are used to. This is not the workout to increase pace or distance. Repeat once every three days. If you want to be outside and it isn’t hot enough, you can replicate higher temps by overdressing; put on a light layer of extra clothing so you’re sweating more underneath.

Iced Track: Here’s where the bag of ice comes in handy. Place the bag with your stuff on the infield of the track. Do an easy warm-up for 10 to 15 minutes and then begin some speedwork. Run for 400m to one mile at 5K pace and then put some ice in your sports bra or under your hat—and repeat. Each time you do this workout, use less ice. Repeat once a week.

Hot Hills: After a mile warm-up, chose a hill you can run up at a comfortable pace in about two to four minutes. Run up, then jog or walk back down, 4–8 times. You can use the ice-bag method to cool off here as well. Do a cool-down walk or jog back and rehydrate immediately. Repeat once a week.

Embracing the heat may seem extreme for some, but runners of all levels can benefit from being a little uncomfortable in all types of weather conditions. As long as you’re aware and stay safe, don’t fear the heat — go outside and run!

Originally published June 2017

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