Running in hot weather presents unique challenges, and heat stroke is one of the top causes of death in endurance events. Whether you’re training through summer or racing in high temperatures, understanding how to manage hydration, electrolytes, sun exposure, and body temperature is critical to staying safe and performing at your best.

Recognising the Dangers: Heat Stroke & Dehydration

Running in the heat puts extra strain on your body. Dehydration, low electrolytes, and heat stroke are all serious risks that can lead to dangerous consequences. It’s crucial to recognise the warning signs:

🚨 Dehydration Signs:

• Dry mouth, excessive thirst

• Dark urine or reduced urine output

• Fatigue and dizziness

• Headaches and confusion

🚨 Electrolyte Imbalance Signs:

• Muscle cramps and weakness

• Nausea and stomach issues

• Confusion or dizziness

• Sluggish performance despite proper hydration (make note of this one!)

🚨 Heat Stroke Signs (Medical Emergency):

• Rapid heartbeat and shallow breathing

• Flushed, dry skin (sweating may stop)

• Confusion or disorientation

• Vomiting and chills

• Loss of consciousness

If you or anyone experiences symptoms of heat stroke, stop immediately, seek shade, and get medical attention. This is not something to push through.

Hydration & Electrolytes: Getting It Right

Proper hydration is more than just drinking water—it’s about maintaining electrolyte balance. When you sweat, you lose sodium, potassium, and magnesium, which are essential for muscle function and preventing cramping.

✔️ Pre-run: Start hydrating early, especially before long runs. ✔️ During the run: Sip fluids regularly. For longer runs, include electrolyte drinks or tablets to replenish lost salts. ✔️ Post-run: Rehydrate with both water and electrolytes to restore balance and aid recovery.

💡 Avoid the mistake of overhydrating with plain water, as it can lead to hyponatremia (low blood sodium), which is just as dangerous as dehydration.

Protect Your Skin: Sunscreen is Non-Negotiable

Long-term sun exposure significantly increases the risk of skin cancer, particularly for runners who train outdoors regularly.

☀️ Apply a high-SPF, sweat-resistant sunscreen before every run, even on cloudy days. ☀️ Reapply during long runs or races—sweat will gradually wear it away. ☀️ Avoid running through water stations or pouring water over yourself, as this can wash off sunscreen and leave your skin unprotected.

Plan Your Route: Chase the Shadows

The route you choose can make a big difference in how much heat you’re exposed to.

🌳 Run early or late: Avoid the hottest part of the day (typically between 10 AM - 4 PM). 🌳 Pick shaded routes: Running in tree-covered areas or trails significantly reduces direct sun exposure. 🌳 Wear light, moisture-wicking clothing: Opt for loose, breathable fabrics to help regulate body temperature.

Smart Strategies for Running in Heat

• Slow your pace: Accept that you may need to adjust your effort level and pace in extreme heat.

• Acclimatise gradually: If you're new to running in hot weather, ease into it over several weeks.

• Listen to your body: Heat stress affects everyone differently—don’t ignore the signs.

Coaching Support for Hot Weather Running

Training in hot conditions requires a smart approach. As a running coach in Bristol, I work with runners to adapt their training, manage hydration, and make smart race-day decisions to stay safe and perform their best.

🏃‍♂️ Want expert guidance to train effectively in all conditions? Get in touch today to ensure your running stays strong and safe year-round.

Running in heat requires respect for the conditions, proper hydration, and careful planning. Stay smart, stay hydrated, and keep enjoying your miles—safely.