CoachingAnswer

HOW DO I RACE IN EXTREME HEAT?

By Anthony WalshRoadman CyclingUpdated 26 May 2026

ANSWER

Racing in extreme heat (30°C+) without strategy can cost 8–12% of performance. The WorldTour approach combines four elements: pre-cooling for 15–20 minutes before the start (ice vest or cold exposure), pacing targets reduced by 5–8% for the first hour, electrolyte-led hydration at 750–1,000ml per hour, and prior heat acclimatisation. Skip any of these and you're managing the heat reactively — which is already losing.

KEY TAKEAWAYS

Pre-cool for 15–20 minutes before the start — lowers core temperature and extends time to heat exhaustion.
Reduce power targets by 5–8% in the first half of a hot race; the second half is where you can push.
Drink 750–1,000ml per hour with electrolytes — plain water at that intake in heat is a sodium dilution risk.
Prior heat acclimatisation (a 10–14 day heat block) is the biggest single performance protection for hot races.

WHO THIS IS FOR

IS THIS YOU?

The rider with a hot-weather target event

You have a summer gran fondo, sportive, or race and want a concrete strategy, not generic warm-weather advice.

The rider who has previously blown up in hot races

You know the feeling of a race falling apart in heat and want the tactical framework that stops it happening again.

THE ROADMAN VIEW

Hot races are where preparation pays off most visibly. The riders who go wrong in extreme heat almost always made the same two mistakes: they started at their normal power and they didn't pre-hydrate. By the time they realised the heat was going to be a problem — usually by the second hour — it was already too late to recover.

The WorldTour framework Anthony has discussed on the podcast is built around the idea of banking margin in the first half. Start cooler than you need to (pre-cooling). Start drinking more than you think you need to (pre-loading). Go slightly easier than you feel you need to in the first hour. All three of these are uncomfortable decisions to make at the start of a race, because you feel good and the legs feel fresh. But they are what the evidence and pro coaching experience prescribe — and they're what keeps you racing strong in hour four while everyone around you is fading.

The prior acclimatisation piece is the multiplier on all of the above. A rider who has done a heat block arrives at the start line with a 4–10% higher plasma volume, a lower resting heart rate, and a cardiovascular system that has already adapted to the thermal demand. All the tactical execution in the race still matters, but it's working from a better physiological starting point.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

Roadman Podcast — Remco heat preparationRoadman Cycling, coaching pillar
The episode analysing WorldTour heat preparation for races covered the race-day execution model: pre-cooling reduces core temperature before the start, structured pacing protects against premature heat exhaustion, and planned electrolyte intake prevents the performance crash that plain water alone causes in extended heat exposure.
Hear it: Remco's Heat Training: Why It Works & How to Gain From It
Sam ImpeyWorld Tour nutritionist
Race-day heat nutrition strategy at WorldTour level begins 2–3 hours before the start with sodium pre-loading to build plasma volume. On the bike, the target is 750–1,000ml per hour with electrolytes. The strategy accounts for the fact that GI absorption capacity in extreme heat can be compromised — having a pre-loaded buffer matters more than trying to maximise in-race intake.
Hear it: Why Pros' 120g Carb Rule Fails Amateurs | Roadman Cycling

PRACTICAL APPLICATION

DO THIS WEEK

Execute a 15–20 minute pre-cooling protocol
Ice vest, cold towels on neck and forearms, or 15 minutes in an air-conditioned room. Ingest cold fluid (2–4°C) during warm-up. The goal is starting the race with core temperature 0.5–1°C below your normal resting temperature. This extends the time before heat becomes a limiting factor.
Pace the first half conservatively
Target 5–8% below your normal effort for a given race duration in the first half. In a 4-hour sportive, ride the first 2 hours slightly easier than you think you need to. The second half is when heat becomes decisive — you want to be one of the riders who still has margin, not one who's already red-lining.
Drink to schedule with electrolytes throughout
750–1,000ml per hour, with sodium in every bottle. Set a reminder on your head unit to drink every 10–15 minutes. In extreme heat, waiting for thirst to signal when to drink means you're already 1–2% behind. Aim to finish the race at the same weight you started — or within 1–2% lighter.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

MISTAKEStarting at normal race power in extreme heat.
FIXThe first hour of a hot race should feel slightly too easy. This is not weakness — it's the tactical decision that determines whether the second half goes well or badly.
MISTAKENot pre-cooling before the start.
FIXPre-cooling is the single most impactful last-minute intervention. Ten minutes with an ice vest and cold fluid at the start line costs nothing and is proven to extend time to heat exhaustion in hot-weather races.
MISTAKERelying on water stops without carrying electrolytes.
FIXIn extreme heat, relying on water stops for all hydration means you have no control over quantity, timing, or sodium content. Carry at least one electrolyte source — tabs or a mix — and use it consistently regardless of what the route provides.

FAQ

FREQUENTLY ASKED QUESTIONS

What temperature counts as extreme heat for cycling?

Above 30°C is where performance degradation becomes significant for unacclimatised riders. High humidity amplifies the effect substantially — 28°C and 85% humidity is harder than 34°C and 20% humidity. Adjust your pacing and hydration strategy based on both temperature and humidity.

Should I take ice at aid stations during a hot race?

Yes. Apply ice to the back of the neck, under arm warmers, or inside shorts. Ice in bottles extends the cooling effect of fluids. Some riders use ice socks down the back of the jersey. Any external cooling in a hot race extends your heat tolerance.

Can I use caffeine in a hot race?

Moderate caffeine (3–6mg/kg body weight) remains performance-enhancing in heat and doesn't meaningfully increase dehydration risk at normal doses. Use your normal caffeine strategy — heat alone is not a reason to avoid it.

How do I know if I'm getting dangerously overheated during a race?

Warning signs: hot, dry skin (you've stopped sweating effectively), confusion or difficulty concentrating, extreme nausea, and very high heart rate at low effort. Any of these warrant stopping, moving to shade, and cooling immediately. Don't try to push through heat illness.

Does heat training help with racing in extreme heat?

Yes — significantly. A rider who has completed a 10–14 day heat acclimatisation block before a hot race starts with a 4–10% higher plasma volume, a lower cardiovascular cost at any given intensity in heat, and improved sweat efficiency. The same race that melts an unacclimatised field is a manageable day for a well-acclimatised rider.

Is it better to wear light or aero kit in a hot race?

Heat dissipation beats marginal aerodynamic gains in extreme heat above 30°C. Light, breathable fabric that promotes evaporative cooling is more important than minimal drag. This is why WorldTour riders often drop skin suits in favour of more breathable race kits in hot Grand Tour stages.

RELATED EPISODES

HEAR THE CONVERSATIONS

Remco's Heat Training: Why It Works & How to Gain From It

Why Pros' 120g Carb Rule Fails Amateurs | Roadman Cycling

Heat Training for Cyclists: +30 Watts FTP | Roadman Cycling