Whether you love hot weather or dread it, there’s no denying it can make running challenging. Heat, humidity, dehydration – they all take a toll on you during the summer months.
Luckily, there are ways to keep running when the temperature rises. If you pick the correct time of day, hydrate well, and dial back your expectations, you can keep training all summer.
Take a few minutes to read through our runner-tested tips and tricks to run strongly in hot and humid weather.
Why Does It Feel Harder to Run When It’s Hot?
Running in the heat feels harder than in cool weather for a number of reasons. First, your body has to work harder to cool itself down, which tires you out much sooner than usual.
Your body temperature naturally rises when you run, but in summer, it shoots up even more with the extra heat. Your heart will begin to work harder to cool you off.
A higher body temperature also means you’re likely to sweat more. More sweat equals more fluid and electrolyte loss, which can quickly get out of hand if you aren’t replenishing at a fast enough rate.
If it’s humid, your sweat isn’t going to evaporate as quickly, sitting on your skin and making you feel even hotter.
How Does the Heat Affect Your Running
Once your body temperature kicks into high gear, it prioritizes cooling itself down over running fast. As your energy is going towards lowering your body temperature, your pace is likely to slow down but your perceived effort will increase.
Studies suggest that for every 1.8 degrees the temperature rises, your running performance suffers by around 0.4%!
Other specific studies, like this one based on the 2018 London Marathon, have shown a direct link between higher temperatures and slower finishing times.
Is It Safe to Go Running in the Heat?
If you prepare and take the necessary precautions, you can run safely in the heat. But every runner is different, and so is every day, so you’ll need to assess the weather, how you feel, and other factors before deciding to head out on a run.
Summer Running Tips to Beat the Heat
Here are the best summer running tips to help you beat the heat and keep performing at your best.
1. Timing Is Key
Getting ahead of the heat—or waiting for it to pass—is one of the best ways to avoid heat-related issues. If you’re used to running in the middle of the day, it’s a good idea to switch it up and either run in the early morning or later evening to avoid the heat.
Keep in mind that if you run in the evenings, there’s still a chance that the sidewalk will be giving off heat if it’s been baking in the sun all day. Running before the sun comes up is the coolest time of day, so set those alarms and get to bed early!
2. Hydration, Hydration, Hydration!
Hydration is vital in any weather, but more so in the heat as you lose fluids faster. But there’s more to it than simply taking a bottle of water with you. Get ahead of potential heat-related problems by understanding hydration before, during, and after your run.
Know Your Sweat Rate
This is key to making sure you’re always properly hydrated. It’s like knowing how heavy your car is on fuel so you can plan your trips better! Your sweat rate is how much fluid you lose during a run.
Every runner’s sweat rate will be different, so we highly recommend testing yourself so you can personalize your hydration strategy.
- Weigh yourself before your run (lbs).
- Keep track of how much you drink during your run (oz).
- Weigh yourself after your run (lbs).
Once you have those three measurements, here’s how to get your sweat rate.
- Subtract your after-run weight from your pre-run weight.
- Convert the final number to ounces (x 16).
- Add the number of ounces you drank during your run.
- Divide the total by the number of hours you ran for.
You can do this during any run, but for ease, we suggest doing a 1-hour run specifically for the purposes of calculating your sweat rate. It could also be more accurate if you do it first thing in the morning before eating anything.
Your final answer will be the amount of water you should be drinking on each run to make sure you’re staying hydrated.
Hydration doesn’t just start when you head out for your run! Staying hydrated should be a daily thing, even before exercising and especially after. If you’re running early in the morning, you must hydrate before your run because your body dehydrates overnight.
Rehydrate with about 16 ounces of water an hour or so before your run. If you’re not up for that long, drink a glass of water 20 to 30 minutes before you start.
If you’re running in the evenings, try to drink 16 or so ounces an hour to 2 hours before your run and another 6 to 8 ounces about 15 to 20 minutes before you head out the door.
During Your Run
Ensure you’re carrying enough water per your sweat rate calculation and the length of your run. You’ll need to decide on an appropriate way to carry this amount of water.
A running hydration belt holding a few water bottles might be enough, but you may want to consider investing in a hydration pack to ensure you’ve always got enough. Try to get through all the water you’re carrying without gulping it down, so sip every few minutes.
If you’re running for an hour or longer, don’t forget to take an electrolyte tablet or powder to avoid electrolyte imbalances.
After Your Run
Rehydrating after your run is also important. Even if you’ve replenished what you lost during the run, you’ve got to stay hydrated afterward, too.
Continue to drink water regularly throughout the day. The key to staying hydrated in the heat is to drink regularly before you feel thirsty.
3. Give Yourself Time to Adapt
Don’t expect to perform the same way in the heat as in cooler weather. While you can run well with the right hydration, gear, and strategy, give yourself time to adapt to the hotter weather, and don’t have unrealistic expectations.
It might also take some time to get used to running at a different time of day. Be patient and ease into the new season.
4. Choose the Right Running Gear
Your clothing can be your best friend or your worst enemy. Make sure your running gear is light, breathable, and moisture-wicking. Consider choosing lighter colors, as darker ones tend to absorb heat.
Opt for polyester or other tech gear over cotton. They don’t hold onto sweat, which cotton does. Some brands also have built-in UV protection, which is a handy feature.
A hat or visor will protect your face from the sun, and sunglasses are key for eye protection.
5. Choose Your Route Wisely
As well as timing your run carefully, consider changing your route. Stick to shady areas like parks and shaded walkways, and avoid routes where you have to run in the full sun.
Pick a route past a water fountain to top up your water if necessary.
6. Focus On Effort and Not Pace
As mentioned earlier, your pace is likely to drop in the heat. You may want to focus more on perceived effort than pace in the heat unless you’re specifically training to hit a certain pace in the heat.
When it comes to easy runs, recovery runs, or runs where you focus on distance instead of time, try to put pace out of your mind and gauge your performance on perceived effort. Also, take breaks when necessary!
7. Manage Your Internal Body Temperature
Aside from staying hydrated and wearing temperature-friendly clothing, take every step to manage your temperature. Splashing yourself with water might not cool you internally, but it can help you refresh yourself a little and make you feel better.
8. Sunscreen Savvy
Just because you’re wearing a hat, it doesn’t mean you don’t need sunscreen. UV rays damage the skin, and sunburn can significantly raise your body temperature.
Choose a sweatproof sunscreen and take some along with you on long runs so you can reapply.
9. Mind Over Mercury: Mental Resilience in the Heat
Part of being prepared for the heat is that you can run with peace of mind, knowing you’re protected and performing as well as possible. But aside from being prepared for hot runs, figure out what keeps you going.
Maybe you need a special playlist to motivate you through difficult runs. Music or an audiobook can distract you from the mental turmoil that comes with feeling hot and bothered and give you the edge you need to push on.
You might also want to do a session or two in the sauna to help your body get used to the heat and build some mental resilience in uncomfortably warm conditions.
10. Run With a Friend
Running with someone else makes not only a friendly distraction from hot weather but also a great safety net. If one of you suffers some nasty side effects from the heat, you’ve got someone to help, or call for help.
If you can’t find someone to run with or prefer running alone, it’s always a good idea to tell someone when you’re heading out, which route you’re taking, and when you expect to be back. That way, if something does happen on the run, someone knows where you are.
11. Listen to Your Body
This is always relevant. If you’re struggling to breathe, feeling dizzy or lightheaded, starting to cramp, or just feeling overwhelmingly exhausted, it might be time to stop and get to a cool place.
While being prepared will help you to tolerate the heat for longer, never disregard the signs your body is giving you. When you aren’t feeling well, rather err on the side of caution and cut your run short.
When Is It Too Hot to Run?
It’s a good idea to check the National Weather Service’s Heat Index to make sure it’s safe to run on any given day. When the heat and humidity are high, the double-whammy may make conditions a little too dangerous to run in.
It’s recommended that you avoid exercising outdoors when the temperature is above 98.6 degrees or the humidity is above 70 percent. But it’s also important to remember that everyone is different, so monitor how you feel in the heat and find your own “breaking point.”
Know the Signs of Heat Exhaustion and Heat Stroke
Dehydration is a common effect of heat, and it’s easy to dehydrate even without realizing it. Keep an eye on your own body and if you notice any of these symptoms, rehydrate immediately:
- Dry mouth
- Feeling hot
More severe dehydration might present with more serious symptoms. If any of these occur, take a break and rehydrate. Consider cutting your run short and taking some time to recover.
- Nausea or stomach cramps
- Difficulty breathing
- Dizziness or lightheadedness
- Muscle cramps
What Not to Do In the Heat
There’s nothing wrong with running in the heat if you take precautions and you’re smart about it. But some things should be avoided if you want to stay as safe as possible. When running in hot weather:
- Don’t take a cold shower or ice bath: You can hop into a pool or a cool-ish shower after your run but never go from being hot to being COLD. You want to lower your body temperature gradually, not suddenly.
- Do intense exercise: If possible, avoid doing high-intensity exercise in very hot weather. It already gets your heart rate up, and when you add the heat, it can overload your body.