top of page


Running in heat and humidity is more than a sweat-fest, it can also be dangerous. But with the right precautions, we can survive the heat and still be able to run and perform our workouts. Whether we live in a country with high heat and humidity summers, or in a climate that is hot year-round, these tips for running in heat and humidity will help stay safe and active.

When Is It Too Hot to Run?

Although we can take precautions when running in heat and humidity, there are times when it’s too hot to run outside. Running in extreme heat can cause heat illnesses like heat cramps, heat exhaustion, and heat stroke.

Avoid running outside or run short easy distances if the heat is above 99°F or 38°C degrees and the humidity is above 88%. If we feel dizzy, nauseous, confused, light-headed, delirious, then it is time to get out of the heat immediately. We should drink water and electrolytes to rehydrate properly, and take a nice cold shower for our body to cool down.

1. Allow Time To Adjust To The Heat. If we live in a climate that changes from cold to hot, give yourself two weeks to adjust to running in the heat. During this time we should focus on easy base runs at a relaxed pace. Focus on our effort level more than our running times and speed.

2. Check Humidity. Humidity can make a big difference in how hot we get while running. If humidity is high, it prevents sweat from evaporating on the skin, which can quickly lead to overheating of our brain and organs. When humidity is high, it makes the heat feel more intense and blocks the body’s ability to cool itself. When we look at the weather, we should look at the heat index, which accounts for the temperature and humidity. If humidity is high and the temperature is high, we should consider working out inside occasionally. If we do run outdoors, we need to go slow, stay in the shade and bring plenty of water with electrolytes.

3. Avoid Intense Workouts On Hot Days. It is a myth that only beginning runners are affected by the heat. In fact, going faster generates more heat, so elite athletes are especially at risk of being affected by the heat. We should avoid speed workouts and fast-paced runs on hot days. Do some relaxed pace base kilometres instead and save the speed workouts and long runs for cooler days or on the treadmill.

4. Pre-Hydrate Before Your Run. Drinking 500ml (2 cups) of water 30 mins to two hours before your run. This is also a good time to have a meal or snack. And 15 minutes before your run, drink another 250ml of water.

5. Hydrate On The Run. Bring hydration on your run. Everyone’s sweat rates vary, as does the amount of heat you are dealing with, so I recommend listening to your body and drinking when you’re thirsty. A good basic hydration guideline for running in the heat is to drink a minimum of 120ml-180ml every 20 minutes.

6. Take Electrolytes. When we sweat, we lose essential minerals through sweat, including sodium, chloride, potassium, magnesium, and calcium. Put an electrolyte tablet in our water or we should take a sports drink with electrolytes for hot weather running. We should look for low-sugar drinks and good electrolytes options. I love High-5 Electrolytes Tablets and you can drop one in a water bottle for hot weather running. High-5 available at Gone Running and Escapade Sport Shops in Hong Kong.

7. Post-Run Rehydration. If we don’t have access or don’t plan to run with electrolytes, to rehydrate after our run or workouts using some good electrolytes will support are muscles, bones and overall health. This is one of my favourite brand of post-run or post-workout electrolytes- BIOSTEEL.

8. Wear Moisture-Wicking Clothing. Running clothes with moisture-wicking fabrics will help us stay dry and keep our body temperature more regulated when running in high temperatures. Look for lightweight, loose clothing made of synthetic moisture-wicking materials such as polyester and nylon, wearing these type of running tops will feel much more comfortable.

9. Protect Against The Sun. Wear a hat, sunglasses, and sunscreen to shield against harmful UV rays. This is one of the best sunscreen for runners for better sweat-proof sunscreen options.

10. Avoid Top Heat Hours. Avoid running at top high heat times, which are between 10am to 2pm. We should run early in the morning or later in the evening to avoid the hottest times. I recommend running in the early mornings as much as possible because the heat often lingers for hours after sundown.

11. Run In The Shade. If we have to run when it’s super sunny, we should try and run in shady areas. Running near water, by trees, and in shade from buildings helps diffuse some of the heat.

12. Adjust Your Training Schedule. As runners we can get caught up in numbers and stats and stick to training plans no matter what, but sometimes Mother Nature has other plans. If our only option is running in heat and humidity, we will need to adjust our training program. This can mean cutting kilometres from long runs, rescheduling speed workouts, or doing shorter runs in general. But even running in the high heat and humidity is still a good version for our training. Once the cooler weather comes back we will fill super strong, so even running at slower pace and shorter distances in the heat we are performing great running performances.

13. Run With A Friend. Having a running friend improves our safety while running in heat and humidity. If we or our running partner gets too hot, then we can stop and help each other to get out of the heat and cool down.

14. Share Your Location. If we run alone, it’s a good idea to share our location, especially if we’re running in heat and humidity. Running apps such as Strava have the option to share our location with a trusted contact in case we get some health issues.

15. Be Flexible. We should adjust our workout program for the heat. We will run slower than usual in the heat. For every 2°C rise in temperature above 25°C, our running pace will slow by as much as 20 to 30 seconds per mile/1.6km.

16. Consider Your Age. Heat affects people more as we get older. Sweat glands become less efficient as we age. If we’re at an increased risk of heat illness based on our age, and when it’s too hot for us to exercise outside, as we get older we should focus on more comfortable running pace or run indoor, on the treadmill.

17. Signs Of Heat illness. Signs of heat exhaustion and heat stroke include heavy sweating, cold, pale, and wet skin, a fast, weak pulse, nausea, vomiting, muscle cramps, tiredness, weakness, dizziness, headaches, and fainting. If we feel any of these symptoms, we should move to a cool, dry place, drink water or a sports drink, and take a cool shower or bath.

18. Exercise Indoors. If you’re in a heat wave that won’t relent or you must exercise during top heat hours, then do an indoor workout. Run on the treadmill, lift weights, go to the gym, or do a HIIT workout at home. The key is to be flexible and stay protected from the most intense heat and humidity.

Signs Of Heat Exhaustion

  • Nausea

  • Dizziness

  • Light-Headedness

  • Vomiting

  • Headache

  • Increased Thirst

  • Weakness

  • Excessive Sweating

  • Muscle Cramping

  • Reduced Urination

  • High-body temperature

Happy Good Running In High Heat And Humidity, Enjoy Easier Pace Runs And Enjoy Some Rain, And Stay Safe!


bottom of page