As a running coach, I love to see my athletes push their limits. But when the temperature climbs, safety becomes the top priority. I’ve coached runners through all kinds of weather conditions and I’ve learned that no workout is worth risking heat illnesses. If you’re planning to train in hot weather, here’s what I teach my runners (and follow myself) to stay safe and smart during summer running.
1. Respect the Heat
First and foremost: heat is not something to “tough out.” It’s a physiological stressor, just like a hard workout. When it’s hot, your heart rate rises, your body struggles to cool itself, and your performance naturally dips.
When the temperature climbs above 80°F (27°C), or the humidity is high, I advise adjusting intensity or shortening the workout. Above 90°F (32°C)? Rethink the run entirely, especially if there’s no shade or breeze. Your safety comes before the schedule.
2. Hydration Starts the Day Before
You can’t “catch up” on hydration mid-run. I encourage my runners to drink consistently throughout the day leading up to a hot workout. A good check: your urine should be pale yellow. Before a morning run, I recommend 8–16 ounces of water upon waking. Then, continue to hydrate as needed during and after the session.
For runs longer than 45 minutes, especially in the heat, electrolyte replacement is critical. Sweat doesn’t just cost you water; it drains sodium, potassium, and magnesium. Sports drinks, electrolyte tablets, or salty snacks can help prevent cramping and dizziness.
3. Run Early, Run Late, or Go Indoors
The coolest parts of the day are just before sunrise and after sunset. Not only is the temperature lower, but the air quality is generally better as well.
I encourage my runners to shift their schedules during heat waves. If it’s not safe or practical to run outside, treadmill workouts are a perfectly legitimate and safer substitute.
Some runners see moving a workout as a failure. It’s not. It’s maturity. The heat doesn’t care how badly you want a tempo run, but your body certainly will.
4. Dress for the Conditions
Technical fabrics are a must in the heat, since cotton holds sweat and traps heat. Lightweight, moisture-wicking clothing is essential. I also advise light colors, since they reflect the sun.
A running hat or visor and UV-blocking sunglasses help protect your head and eyes.
Don’t forget sunscreen. Skin damage and sunburn impair the body’s cooling ability and increase heat stress. Apply a sweat-resistant SPF 30+ before you head out.
5. Know the Warning Signs
I teach every runner I coach the early symptoms of heat exhaustion and heat stroke. These are not just buzzwords. They can become serious medical emergencies.
Watch for:
- Dizziness or lightheadedness
- Nausea or chills
- Weakness or unusual fatigue
- Goosebumps in the heat
- Cessation of sweating
- Confusion or slurred speech
If you feel off, stop immediately, get to shade, and hydrate. If symptoms persist or worsen, seek medical help. No workout is worth your health.
6. Adjust Your Expectations
In high heat, your pace will slow. Your body is working harder to stay cool, and that costs energy. I encourage my athletes to focus on effort, not splits. Heart rate training or perceived exertion can help you train effectively without overreaching.
Heat and humidity place extra stress on your body, making it harder to maintain your usual pace. That’s okay. Listen to your body and slow down.
Trust me: if you train smart in the heat, you’ll build durability and aerobic capacity. Just be patient and humble.
Rule of thumb: For every 5°F above 60°F, consider slowing your pace by 30–60 seconds per mile.
7. Shorten or Split Up Your Runs
If the heat is extreme, break your run into shorter segments or opt for multiple shorter sessions. Even 20-minute runs can help maintain fitness when combined with cross-training or indoor workouts.
8. Make Recovery a Priority
After a hot run, your body needs extra care. Rehydrate with electrolytes, get out of the heat, and prioritize recovery nutrition. A cool shower or ice bath can help lower core temperature.
I also advise runners to monitor how they feel later in the day. Headaches, fatigue, or low appetite can be signs of incomplete recovery from heat stress.
Running in the heat takes a bigger toll on your body. Make sure you’re sleeping well and taking rest days seriously.
9. Acclimate Gradually
Give your body time to adapt to hotter conditions. Gradually increase your exposure over 1–2 weeks. You’ll notice your body begins to sweat more efficiently and your tolerance improves.
Don’t expect instant results: Your heart rate may be higher, and you’ll feel fatigued earlier. Over time, your body will become more efficient at cooling itself and regulating heat.
More About Summer Running
- Best Hand-held Water Bottles for Running
- Tips for Surviving Hot Weather Marathon Training
- 7 Tips for Running Races in Hot Weather
Running coach, avid runner, and fitness writer Christine Luff is an RRCA-certified running coach and ACE-certified personal trainer. Founder of the website Run for Good and author of the book Run for Good: How to Create a Lifelong Running Habit, she coaches runners, from beginners to advanced, who are training for races, from 5Ks to marathons.
