Training · May 02, 2025

How to Train and Race in the Heat Without Melting Your Performance

Whether you’re gearing up for a summer event or just trying to stay consistent in the heat, this guide will help you adapt your sessions, sharpen your strategy, and recover like a pro so you can thrive when others wilt

When the 2025 London Marathon delivered unseasonably hot conditions last month, tens of thousands of runners were left reeling. What was meant to be a fast spring race turned into a survival mission, with athletes at every level struggling to keep pace and stay upright.

The truth is, when temperatures spike, everything changes — your pacing, fueling, recovery, even your mindset. But with the right strategy, heat doesn’t have to melt your performance. It can become a powerful training stimulus and, with proper preparation, a competitive advantage.

Fuel for the heat with our award-winning sports nutrition

This guide is your blueprint for training and racing in the heat. Whether you're heading into a summer event or simply want to get the most from your workouts during a heatwave, we’ve got you covered — from hydration and clothing to acclimatisation and recovery.

Why Heat Hits Harder Than You Think

Training in high temperatures places serious stress on the body. As the mercury climbs, your body diverts blood away from working muscles to the skin to keep you cool. That means less oxygen delivery, more fatigue, and a rising heart rate even at usual paces.

It’s not just a ‘mental game’ — it’s physiology. Your sweat rate increases, your perception of effort goes through the roof, and dehydration can creep in faster than you expect. If you’ve ever felt like your easy run turned into a tempo session just because the sun was out, you’re not imagining it.

This is where many go wrong. They push through as if nothing’s changed and wonder why their recovery suffers or their performance drops. But with smart adjustments, heat can actually help you grow stronger and more resilient.

Training in the Heat – What to Change and Why

Adjusting the Session, Not Just Your Mindset

When it's hotter than normal, trying to hit your usual training paces is like bringing a knife to a gunfight. Instead of fighting the heat, work with it.

Don't worry if you run slower when it's get hot - it's perfectly normal

Focus on rate of perceived exertion (RPE) rather than your watch. If your usual 5K pace now feels like a tempo effort, slow down. That effort still brings the training benefits — and crucially, it protects your recovery.

This is especially important for those training for an event. Your body still adapts when you go slower in the heat, and the training effect is often more profound because of the additional stress load.

If a workout looks too aggressive for the heat, adjust it. Shorten intervals. Take longer rest periods. Add walking breaks. None of this means you’re slacking — it means you’re training smart.

Dress for the Conditions

What you wear matters. Loose-fitting, technical clothing in light colours helps heat escape more easily. Moisture-wicking fabrics keep sweat moving away from your body so it can evaporate — your body’s natural cooling mechanism.

A lightweight cap sun protection, and a good pair of sunglasses reduces the strain of squinting in bright sunlight. Don’t skip sunblock either — it’s not just about avoiding sunburn, it helps your skin function better under heat stress (but don't overdo it).

Fuel and Hydrate Like a Pro

Hydration isn’t just about drinking more water. It’s about keeping your body in fluid balance — and that includes electrolytes. Sodium, potassium and magnesium are all lost in sweat and need to be replaced.

With 100% natural ingredients (including electrolytes) and no UPFs, preservatives or other nasties, Chia Energy Gels are your perfect training and racing fuel when temperatures crank up

Pre-hydrate before your session with water and electrolytes, especially if it’s first thing in the morning. During the session, drink to thirst, but don’t wait until you’re gasping — sip regularly, especially on efforts over 45 minutes.

Hot weather also affects your digestion. Heavier, greasy snacks can feel like a brick in your gut. This is where natural options like our Amore Energy Bar or Chia Energy Gel come into their own — gentle on the stomach, rich in slow-release carbs, and easier to digest even in the heat.

Recovery Takes Longer in the Heat

Heat isn’t just hard during your workout — it continues to affect your body afterwards. Recovery in hot conditions is slower because your body’s been pushed harder, even if the session looked easy on paper.

Help your body bounce back by prioritising hydration post-session. Water alone may not cut it — include electrolyte drinks or foods rich in potassium like bananas, coconut water or leafy greens.

Use cold water immersion or cool showers if available. They reduce inflammation and help regulate body temperature faster. Keep your sleep environment cool and dark, as heat can disrupt deep sleep — the kind you need most after a tough session.

And don’t forget food. Anti-inflammatory ingredients like turmeric, berries, and leafy greens can support recovery and reduce the impact of heat-induced stress on your system.

Post-session, chugging just water might not cut it

Acclimatisation vs Acclimation – And How to Use Both

These two are often used interchangeably, but they’re slightly different.

Acclimatisation happens when you gradually adapt to hot environments outdoors, like running in the midday sun during a summer holiday
Acclimation refers to heat exposure in a controlled environment — like training in a heated room, using a sauna or taking hot baths post-workout

Both approaches help your body become better at managing heat: improving sweat rate, fluid retention, and cardiovascular efficiency.

You don’t need a heat chamber to adapt. A simple 10- to 14-day protocol can work wonders:

Start with shorter sessions (20–30 minutes) in the heat and build gradually. Add post-workout sauna or hot baths if outdoor heat isn’t an option. Most importantly, practise drinking and fuelling in the heat. Your gut, just like your muscles, needs training too.

Racing in the Heat – Strategy Over Speed

The 48-Hour Window

Preparation starts well before the race. In the two days leading up, stay out of direct sun whenever possible. Hydrate well with added electrolytes, and avoid dehydrating drinks like alcohol.

Light, carbohydrate-rich meals help keep glycogen stores topped up without weighing you down. Cooling strategies like ice slushies or cold drinks can help pre-lower your core temperature on race morning.

Adjusting Your Expectations — and Your Pace

When temperatures rise, use RPE to guide your pace rather than the hard data you're used to

This is where many go wrong. They aim for their ‘A goal’ pace and try to brute force it through the heat. That usually ends with a meltdown — physically and emotionally.

In hot races, pacing needs to reflect the conditions. Start more conservatively than you think you should. Monitor effort, not splits. If you’re using heart rate, remember it’ll drift higher over time — that’s normal, but don’t let it push you into the red early.

Use aid stations wisely. Don’t just drink — pour water over your head, neck and wrists. Cooling your skin helps reduce core temperature and delay overheating.

Stay Strong Mentally

Racing in heat is tough. There’s no getting around it. But mindset makes a difference. Break the race into segments. Focus on staying in control. Use mantras. Smile (yes, it really does help). A positive expression can lower your perceived effort and help you keep going when others fade.

Post-Race Recovery – Don’t Drop Your Guard

The race is over, but the job isn’t done. Heat can continue to affect you for hours afterwards.

Get into the shade immediately. Start cooling your body with wet towels or cold drinks. Rehydrate slowly and consistently — again, include electrolytes, not just plain water.

Replenish your energy stores, kick-start muscle repair and flood your stressed immune system with vitamins - all with just one serving of Protein & Greens Powder

Eat something light to start — your digestive system may be a bit shocked. Once things settle, refuel with carbs, protein and anti-inflammatory foods. After a big race-day effort, a serving or Protein & Greens Powder or our Elite Meal Replacement Shakes make an excellent first meal post-race when chewing a plate of food feels like a big ask.

Keep an eye out for symptoms of heat illness like dizziness, confusion or nausea — these can be delayed and are signs your body needs more time to recover.

Final Thoughts – Turn the Heat into Your Edge

Hot weather is a performance curveball — but it doesn’t have to be a disaster. With smart training, better fuelling, and a few simple adaptations, you can not only survive hot sessions and races — you can thrive in them.

Heat makes everything harder. But it also makes you stronger. Lean into it, respect it, and use it to unlock new levels of resilience and performance.