While we’re not exactly known for scorching summers in the UK, when a heatwave does hit, it can catch runners off guard. Running in hot weather isn’t just uncomfortable it can be dangerous if you’re not prepared. Dehydration, overheating, and fatigue can sneak up quickly, especially when we’re not used to training in high temperatures.
Here’s your complete guide to running in the heat, packed with practical tips for staying safe, hydrated and on track with your training whether you’re tackling a summer 10K, marathon training, or keeping up your weekly Parkrun habit.
🌡 What Counts as “Hot” in the UK?
In the UK, anything above 20°C can start to feel tough during a run especially under direct sun. Once temperatures creep up to 25°C and beyond, your performance can drop significantly and the risk of heat-related illness rises.
💧 1. Hydration Is Key (Before, During & After)
One of the biggest mistakes UK runners make is waiting until they’re thirsty to drink. In the heat, your body loses fluids faster through sweat even if you don’t feel it.
✅ Hydration tips:
- Pre-run: Drink a glass or two of water an hour before heading out.
- Mid-run: For runs over 45–60 mins, carry water (bottle, hydration vest, or belt).
- Post-run: Rehydrate with water or add electrolytes to replace lost salts.
- Bonus: Check your pee! Pale yellow = hydrated. Dark = time to drink up.
☀️ 2. Run Early or Late to Avoid the Heat
Plan your runs around the sun. The UK summer sun is strongest between 11am and 3pm, so aim for early morning or late evening.
Not a morning person? Even a 6pm jog is cooler and safer than lunchtime heat. Plus, you’ll avoid sunburn and reduce your exposure to UV rays.
👕 3. Dress Smart: Light, Loose & Breathable
Your go-to running hoodie won’t do in a heatwave. The key is to wear technical fabrics that wick sweat and allow airflow.
Best summer running gear:
- Lightweight, moisture-wicking tops (ditch cotton!)
- Running shorts or breathable leggings
- A lightweight cap or visor to shield your face
- Sunglasses with UV protection
- High-SPF sweat-proof sunscreen, especially on your neck, face and shoulders
🧠 4. Listen to Your Body & Adjust Your Pace
Heat places extra stress on your cardiovascular system. Your heart rate rises faster, and your body works harder to cool you down.
Adjust expectations:
- It’s OK to slow down in fact, it’s smart.
- Turn intervals or tempo runs into easy runs on very hot days.
- Walk breaks are totally fine and often necessary.
Don’t push through dizziness, cramps or nausea. If you feel off, stop, rest, cool down and hydrate.
🏃♂️ 5. Shorten or Split Your Runs
Running for an hour in 28°C heat isn’t ideal. Consider shortening your runs or splitting them up do 20 minutes in the morning and another 20 in the evening if needed.
Alternatively, take some runs indoors a treadmill in an air-conditioned gym or even some strength work at home can help maintain fitness while avoiding the heat.
🍌 6. Fuel Wisely in the Heat
You might not feel hungry after a hot run, but post-run nutrition is still vital. Stick to lighter meals rich in carbs, protein and salt.
Great options for summer runners in the UK:
- Smoothies with banana, protein powder and frozen berries
- Wholemeal toast with eggs and avocado
- Cold pasta salad with chicken or tofu and veg
- Greek yoghurt with granola and honey
And don’t forget replenish electrolytes, especially after very sweaty sessions.
🧊 7. Cool Down, Literally
After your run, help your body recover:
- Take a cool shower (not freezing) to lower your core temp,
- Sit in front of a fan or use a cold damp towel on your neck,
- Avoid tight, non-breathable clothing,
- Rest in the shade or indoors until your body temp returns to normal.
UK runners might not face tropical heat every day, but when summer hits, it pays to be prepared. By adjusting your hydration, clothing, pace, and timing, you can still enjoy your runs while staying safe.
Remember: no training plan is worth risking heat exhaustion. Listen to your body, ease off when needed, and embrace the slower pace of summer.
🔥 BONUS TIP: Running slower in the heat builds strength and mental resilience. When cooler weather returns, you’ll feel the benefits.
