CoachingAnswer

WHAT IS THE HEAT ACCLIMATION PROTOCOL?

By Anthony WalshRoadman CyclingUpdated 26 May 2026

ANSWER

The heat acclimation protocol used by WorldTour teams runs 10–14 days. Each day: complete a 60–90 minute moderate session in 30–35°C ambient temperature, then remain in the heat for 20–30 minutes post-ride. No full cooling until the passive period ends. Over 10–14 consecutive days this triggers a 4–10% plasma volume expansion, increases red blood cell mass, lowers resting heart rate, and improves sweat efficiency. Repeat daily — consistency is the mechanism.

KEY TAKEAWAYS

10–14 days is the minimum for full physiological adaptation; fewer than 7 days produces acclimatisation, not full adaptation.
Post-ride passive heat exposure (20–30 min in kit, no fan) is as important as the session itself.
Room or ambient temperature target: 30–35°C. Below 28°C the stimulus is too weak.
Reduce overall training load during the block — the heat adds significant cardiovascular demand.

WHO THIS IS FOR

IS THIS YOU?

The amateur targeting a key summer event

You want to arrive at your goal race or sportive with full heat adaptations in place, not scrambling to cope on the day.

The rider following the WorldTour heat protocol

You've heard about Remco's or other pros' heat blocks and want the exact protocol, not a vague summary.

THE ROADMAN VIEW

When the Roadman podcast broke down Remco Evenepoel's pre-race heat protocol, what struck most listeners wasn't the science — it was the simplicity. No altitude chamber. No sports science team standing over him. A structured daily routine of riding in heat and staying in it. That's the whole protocol. The elegance is that the adaptation is very robust once you do it consistently.

The two numbers that matter are 10 and 30. Ten days is the minimum for the full haematological response — you can see plasma volume changes at day 5, but the EPO response and red blood cell adaptation take longer. Thirty minutes of passive heat post-ride is the second daily requirement that most riders skip or cut short. That post-session period, when your core temperature is still elevated and you're sitting in kit without a fan, is where much of the adaptation signal comes from.

The other thing coaches are clear about: reduce your training load during the block. A heat acclimatisation block is not a regular training week with added heat. It's a dedicated adaptation block with moderate sessions inside. Trying to stack your normal interval load on top of daily heat stress leads to accumulated fatigue, not better adaptation.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

Roadman Podcast — Remco heat training protocolRoadman Cycling, coaching pillar
The protocol breakdown covered the WorldTour template precisely: 10–14 consecutive days, each with a moderate session in elevated ambient temperature (30–35°C), followed by 20–30 minutes of passive heat exposure with no active cooling. Adaptations documented include plasma volume expansion of 4–10%, increased haemoglobin concentration, and reduced resting heart rate.
Hear it: Remco's Heat Training: Why It Works & How to Gain From It
Roadman Podcast — 30-watt FTP heat protocolRoadman Cycling, coaching pillar
The heat protocol episode gave the step-by-step implementation for amateur application, confirming the same 10–14 day structure and emphasising that the passive post-ride heat period — often overlooked — is integral to the adaptation, not an optional extension.
Hear it: Heat Training for Cyclists: +30 Watts FTP | Roadman Cycling

PRACTICAL APPLICATION

DO THIS WEEK

Day 1–3: Establish the environment and calibrate intensity
Set room to 30–35°C, turbo trainer or warm outdoor riding, 60–75 minutes at zone 2. Expect heart rate to be 10–15 bpm higher than usual at the same power. This is normal — don't chase your normal numbers. After the session, sit in kit without a fan for 20 minutes.
Days 4–10: Build the passive period
Extend post-ride heat exposure to 25–30 minutes. Session duration can increase slightly to 75–90 minutes if fatigue is manageable. Maintain moderate intensity throughout. Weigh yourself before and after each session and replace fluid losses at a rate of 1.5x the weight lost.
Days 11–14: Maintain and taper
Reduce session intensity slightly — the adaptation is largely complete by day 10. Maintain the daily heat exposure to consolidate gains. Allow 5–7 days of normal training before your target event so fatigue from the block clears before race day.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

MISTAKEStopping the block at 7 days because it feels like enough.
FIXPlasma volume changes appear early, but the deeper haematological adaptation takes 10–14 days. Cutting the block short leaves gains on the table.
MISTAKEJumping into a cold shower immediately after the session.
FIXThe 20–30 minute passive heat period post-ride is a core part of the protocol. Cold water immediately after the session cuts the adaptation signal short.
MISTAKEContinuing a full training load alongside the heat block.
FIXThe heat block is a deliberate physiological stressor. Reduce other training to manageable levels — hard sessions and heat exposure on the same day will accumulate fatigue faster than adaptation occurs.

FAQ

FREQUENTLY ASKED QUESTIONS

Can I do the heat acclimation protocol outdoors?

Yes, if ambient temperatures are consistently 30°C+ and you can manage the post-ride heat exposure. The challenge outdoors is controlling the environment — wind and shade can cool you faster than the protocol requires. Indoor turbo training in a warm room is more controllable.

What happens to training performance during the block?

Expect power at your normal heart rate to drop, particularly in the first week. This is the heat tax. By the second week, performance in the heat starts recovering, and sea-level performance after the block exceeds your pre-block baseline.

Do I need to eat more during a heat block?

Not significantly more calories, but your carbohydrate and fluid needs increase. Heat suppresses appetite in some athletes — resist the urge to under-fuel, as the adaptation requires adequate glycogen for the daily sessions.

When should I start the heat block relative to my event?

Aim to complete the 10–14 day block with 5–10 days of normal training before your event. This clears acute fatigue while keeping the adaptation fresh. Starting the block within a week of the event risks arriving fatigued.

Can the heat block be repeated multiple times in a season?

Yes. Two or three heat blocks in a season, each 10–14 days, timed before key events is a reasonable approach. The adaptations reverse within 2–3 weeks of ending a block, so running them opportunistically before priority races is the most efficient use.

Is the protocol different for beginners vs trained athletes?

The structure is the same, but beginners should start with shorter sessions (45–60 minutes) and shorter passive periods (15–20 minutes) and build more gradually. Less-trained athletes also tend to have stronger early adaptation responses.

RELATED EPISODES

HEAR THE CONVERSATIONS

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

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

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