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HOW LONG BEFORE A HOT EVENT SHOULD I HEAT TRAIN?

By Anthony WalshRoadman CyclingUpdated

WHO THIS IS FOR

IS THIS YOU?

The rider with a fixed hot-weather race date

You know exactly when your event is and want to reverse-engineer when to start heat training to peak on the day.

The rider planning around a packed calendar

You have other training priorities and need to slot a heat block in without sabotaging the rest of your build.

THE ROADMAN VIEW

The Roadman view

The timing question is where most amateurs get heat training wrong, and it's a shame because the protocol itself is the easy part. People do the work — 14 days of sweating on the turbo — and then mistime it. Either they finish three weeks before the event and the plasma volume has quietly drained away by race day, or they're still doing heat sessions in race week and they roll up to the start line cooked. Both waste the adaptation.

Anthony has talked through this on the podcast off the back of the Remco heat protocol coverage. The pros don't guess the timing — they count back from the target. The number that matters is the gap between your last heat session and the event: you want 5 to 10 days. Long enough that the fatigue from daily heat stress has cleared, short enough that the plasma volume and red cell adaptation are still in play. Slot a 10–14 day block in front of that gap and you start it around three weeks out.

The free adaptation most amateurs skip isn't the heat block itself — plenty of riders do that. It's the maintenance dose afterwards. If your event sits four or five weeks past the block, two or three short heat sessions a week holds most of the adaptation in place. It's a fraction of the original effort and it's the difference between arriving acclimatised and arriving with a faded memory of being acclimatised.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

  • Roadman Podcast — Remco heat training breakdownRoadman Cycling, coaching pillar

    The WorldTour heat protocol coverage was specific on timing: teams schedule heat blocks to finish 7–14 days before the target race, never the day before, because the last days of a block carry fatigue. Plasma volume begins reversing within 1–2 weeks of stopping, so the block is timed to land its peak benefit on race day rather than ahead of it.

    Hear it: Remco's Heat Training: Why It Works & How to Gain From It
  • Dr Stephen SeilerExercise physiologist, University of Agder; codified 80/20 polarised training

    Any adaptation block has to be timed against its own fatigue and decay curves. With heat training, the adaptation peaks while the acute fatigue from daily thermal stress is still present, so a short recovery gap before the event is essential — long enough to shed fatigue, short enough that the physiological gains haven't reversed.

    Hear it: 80/20 Training to Ride Faster | Dr Stephen Seiler

PRACTICAL APPLICATION

DO THIS WEEK

  1. Count backwards from the event

    Mark race day. Subtract 5–10 days for the recovery gap — that's your last heat session. Subtract another 10–14 days for the block itself. That start date is roughly 3 weeks before the event. Put the block in your calendar around it.

  2. Protect the 5–10 day gap

    Between the last heat session and the event, return to normal (non-heat) training and a taper. This window clears the accumulated fatigue of daily heat exposure while the plasma volume and red cell adaptation are still fresh.

  3. Add maintenance if the event is further out

    If your block finishes more than two weeks before the event, run 2–3 maintenance heat sessions per week — a 60-minute moderate ride with 20 minutes post-ride passive heat. This holds most of the adaptation through to race day.

  4. Don't stack the block on top of your hardest training

    Reduce other intensity during the block. Daily heat stress plus full interval load accumulates fatigue faster than adaptation. Treat the heat block as a dedicated phase, then return to your normal sessions in the recovery gap.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

  • MISTAKEFinishing the heat block the day before the event.

    FIXThe final days of a block carry real fatigue. Leave a 5–10 day gap between your last heat session and the event so that fatigue clears while the adaptation stays fresh.

  • MISTAKEFinishing the block three or more weeks early.

    FIXPlasma volume starts reversing within 1–2 weeks. If the event is that far out, keep the adaptation alive with 2–3 maintenance heat sessions a week rather than letting it fade.

  • MISTAKECramming the whole block into the final week before the event.

    FIXThere's no time for fatigue to clear, and the deeper adaptation isn't even complete at 7 days. Start roughly 3 weeks out so the block can run its full 10–14 days with a recovery gap after it.

FAQ

FREQUENTLY ASKED QUESTIONS

How many days before a hot race should I finish heat training?
Finish your last heat session 5–10 days before the event. That gap clears the fatigue from daily heat stress while the plasma volume and red blood cell adaptation are still at or near their peak. Finishing the day before leaves you fatigued on the start line.
How far in advance do I need to start a heat block?
Roughly 3 weeks before the event. A 10–14 day block plus a 5–10 day recovery gap works backwards to a start date around 21 days out. Earlier than that and you'll need maintenance sessions to stop the adaptation fading.
What if I only have a week before my hot event?
A 7-day block won't produce full adaptation, but it still drives early plasma volume expansion and useful acclimatisation. Do it, accept partial benefit, and keep the last day at least 2–3 days before the event so the worst of the fatigue clears.
Can I keep the adaptation if my event is a month after the block?
Yes — run 2–3 maintenance heat sessions per week after the block. A 60-minute moderate ride with 20 minutes of post-ride passive heat is enough to hold most of the plasma volume and red cell adaptation for several extra weeks.
Should the heat block replace my taper?
No. The heat block sits before the taper. Finish the block 5–10 days out, then taper as you normally would into the event. The block builds the heat adaptation; the taper sheds fatigue. They're separate jobs done in sequence.
Does the timing change for a very long event versus a short one?
The block and gap structure is the same, but for very long hot events the hydration and pacing strategy matters even more, since the heat tax compounds over hours. The acclimatisation buys you a higher plasma volume and better sweat efficiency that pays off most over long durations.

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