The Ultimate Guide To Running In The Heat

summer running

Summer is finally here, and while I am so thankful for the warmer weather, the heat and humidity can make running more difficult. Running in the heat can be hard, but the good news is it’s not impossible.

With a few preparations, considerations, and adjustments, you can safely adjust to a successful running season.

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What Happens To Your Body When You Run in the Heat?

So let’s start by talking about what happens to your body when you run in the heat. Running in the heat is hard on your body. Exercising, even in cold temperatures, causes your body temperature to rise. When running in the heat, body temperature increases even more.

Once your body reaches a temperature of 102 degrees, it can no longer effectively cool itself and you will experience a serious drop in performance. Your body begins to divert blood to the skin to cool it rather than focusing on your running performance.

There are multiple other factors that affect your body when you run in the heat. The ultimate result is that running in the heat is harder on your body and therefore reduces your running performance.

Dangers of Running in the Heat

There are multiple dangers that come with running in the heat. You need to be sure you are aware of the warning signs. If you begin to experience muscle cramps when running in the heat, they may be heat cramps.

If you begin to experience thirst, weakness, dizziness, profuse sweating, or fatigue, it may be a sign that you are experiencing heat exhaustion.

If you experience signs of heat exhaustion, you should go to a cooler place with air conditioning immediately. You should drink water, and take a cool shower or use a cool compress.

The next level of heat illness is heatstroke. Heatstroke is very dangerous. A few signs of heatstroke include having a throbbing headache, not sweating, or experiencing nausea.

The body temperature rises above 103, the skin is dry and hot, and the person may have a rapid, strong pulse. At this level of heat illness, the person may lose consciousness.

It is important to take any and all warning signs seriously. 911 should be called immediately if someone is experiencing signs of heatstroke. The person should also be taken to a cooler, air-conditioned place immediately.

When running in the heat, it’s very important to listen to your body and watch for warning signs.

Now I’ll share a few tips to ensure that you are prepared to safely run in the heat:

Allow Yourself Time To Adapt

Something that I want to start by sharing is that running in the heat is something that your body needs to adjust to. It can take approximately 2-4 weeks of running in heat and humidity for your body to adapt to the conditions.

You should reduce the intensity of your running while your body adapts to running in the heat. Take it easy those first few weeks to allow your body time to adjust to the temperature and humidity. Once your body is adjusted, you can get more serious about training.

Run Early In the Day

It’s a great idea to schedule your runs for early in the morning when the day is at its coolest. This is when the sun is at its weakest. This will give you the best chance to run in conditions that are more favorable for running.

Running early will help you to take advantage of the coolest time of day so that the mid-day heat has less impact on your training.

Hydrate! Hydrate! Hydrate!

Making sure to hydrate yourself is so important when running in the heat! Consuming extra fluids and electrolytes while heat training is crucial. You want to be sure to avoid dehydration. You can carry a water bottle or hydration pack on your runs filled with water or sports drink.

The extra heat will make you sweat and, therefore, will make it so that your body dehydrates faster. Drink plenty of water before, during, and after your run to make sure that your body stays well-hydrated.

I recently did an interview with Prevention Magazine where I recommend my favorite hydration packs and give tips for choosing the right one. If you’re interested in investing in a hydration pack for your runs, check it out!

Don’t Expect a Peak Performance In The Heat

As I mentioned earlier, running in the heat is harder on your body. This causes your running performance to decrease because your body has to work harder to cool you down and keep you safe. Don’t go into a hot run expecting to PR.

As a matter of fact, should expect a decrease in marathon performance by 6-7% when it’s over 70 degrees and a decrease in performance by 12-15% when it’s over 80 degrees.

Wear Moisture-Wicking Running Gear

When running in the heat, be sure to dress appropriately. Wear something light and loose-fitting. It can be helpful to choose clothing that is light-colored so that it repels the heat rather than absorbing it.

Choose moisture-wicking running gear so which will help to keep you dry. Here are a few great options:

The Ultimate Guide to Running In The Heat

How do you stay cool in the heat?

You May Also Be Interested In:

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How To Start Running When You’re Out Of Shape


  1. Okay I so needed this at the beginning of summer…! I was on a running kick for a few weeks and then the weather was SWELTERING! I’m totally a seasonal runner and I only like to run when the temperature won’t cause a heat stroke. Thanks so much for the advice!

  2. Great motivation as we begin the summer . Very informative! good tips for someone is a beginner runner. Thanks for the advice .

    1. I’m glad you found them useful!

  3. Great tips, Lauren!
    Running early in the day is definitely worthwhile. If you’re lucky, you may even catch the sunrise!

    1. Yes! The sunrise is the best part!

  4. I’m actually a much better runner in the heat/humidity than in the cold. While everyone is out there suffering, I’m loving every minute of it! The low humidity days are best, obviously, but I just love summer running so much!

    1. Me too Rachel!! I love it!

  5. This year, I have made a real effort to adapt and push through the summer heat. So far it’s working ok but summer is still my 4th favorite season to run in

    1. That’s great! At least you’re pushing through!

  6. These are all great points. I’m a big fan of running in just a sports bra and shorts. On a recent Rogue Running podcast, Chris McClung says that if it’s extremely humid, there’s no tech shirt that will wick the moisture away so you’re better off showing as much skin as possible. If it’s hot and dry, a shirt is probably okay. The other big thing, like you say, is to just be patient and let yourself get acclimated. It does get easier!

  7. While I begrudgingly tolerate Winter, I much prefer the heat of Summer. I seem to have a higher tolerance of the heat/humidity than a lot of people, and I’m ever so grateful. Thanks for the added info about heat exhaustion and heat stroke!

    1. I am the same way. I have a high heat tolerance. I’m glad you enjoyed it!

  8. While I prefer running in warmer weather, it is definitely more challenging! These are great tips. I always try to run as early as possible in the summer to beat the heat.

    1. Running early in the summer is a great idea!

  9. Too many times I’ve missed my early run and ended up running in the late afternoons/evenings when it has still been so hot out. Luckily, I think my body has adapted but it wasn’t fun. So getting it done early, really is worth the un-Godly hour you have to get up!

  10. This year we had very little time for adaptation. It’s been pretty nice in the mornings and then boom! Today it is almost 30 degrees warmer than it was last week! At 5 am!

  11. Great tips! Always good to remind ourselves of these tips each year as summer rolls around

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