How to Train for Hot Weather Triathlon When You Live in the Netherlands
Mallorca was supposed to be hot.
Ironman 70.3 Alcudia has a reputation. The bike climbs. And the run cooks. Athletes I respect had warned me about those two exposed beach loops in the sun. So I went there ready for it — I'd thought about the heat for weeks.
Then race morning came. Rain in the forecast. Storms by midday. Wind — everything I thought I'd left behind in the Netherlands.
The heat never showed.
I prepared for a race day I didn't get.
And that is exactly the problem. When you train in a flat, cold, windy country and race somewhere warm, you don't choose which version of race day turns up. Sometimes it stays cool and you got lucky. Sometimes it's 30 degrees on the run, and the athletes who never prepared for it fall apart at kilometre 14.
If you train in the Netherlands and race somewhere warm — Mallorca, Lanzarote, Portugal, the south of France — you already know this gap exists. You feel fit at home. Then the heat hits, and your body has no idea what to do with it.
This isn't a niche worry, either. Heat training was a dedicated coaching session topic at USA Triathlon's 2026 Endurance Exchange in January. The science is settled: you can train your body to handle heat. You just have to do the work before you arrive.
Here's how to do it from a cold, flat country — no training camp, no altitude lab required.
Why Dutch athletes are especially exposed to heat on race day
You train in 8–15 degrees for most of the year. Your body is brilliant at it. Cold harbour swims, wind on the bike, grey skies on the long run — the Netherlands makes you tough in a very specific way.
But it gives you almost no heat stress. Ever.
So when you land in Mallorca in May or Klagenfurt in July, your body has never once rehearsed cooling itself at race intensity in 28–32 degrees. It doesn't know how. Heat tolerance is a skill the body learns through exposure — and a flat, cool country simply never teaches it.
I get it. You did the long rides. You hit the numbers. And then a number you never trained for — the air temperature — quietly rewrites your whole race. What the Mallorca course demands in heat and wind caught out plenty of strong riders the year I raced it, even on a cool day.
What heat actually does to your performance
Forget the physiology lecture. Here's what you'll actually feel.
Your heart rate drifts. Same pace, same power — but a higher heart rate, because your body is sending blood to your skin to cool you instead of to your legs. Your perceived effort climbs with it. Zone 2 starts to feel like zone 3 for no obvious reason.
You sweat more and lose more salt, so dehydration creeps in faster than you notice. And your real pace at any given heart rate drops. Race to your usual home numbers in the heat, and you'll redline without realising it — right up until the moment your body stops cooperating.
Most destination 70.3 run courses make it worse. Two exposed loops, almost no shade, mid-afternoon sun. There's nowhere to hide.
In heat, your old numbers lie to you.
Heat adaptation you can do at home — no camp required
The good news first: it works, and it works fast. Most athletes get meaningful adaptation in 7–14 days of regular heat exposure. You can do all of it from the Netherlands.
The principle is simple. Get your core temperature up, regularly, and let your body adapt — more plasma volume, earlier sweating, a lower heart rate at the same effort. Three practical ways to do that:
Sauna after training. The easiest one. 15–20 minutes in a sauna right after a session, 4–6 times across the 10 days before you travel. Start shorter, build up. Hydrate before and after.
Overdress on the indoor trainer. Long sleeves, leggings, fan off, door closed. 45–60 minutes easy. You're not chasing watts here — you're chasing heat. Ugly, sweaty, effective.
A hot bath if you have no sauna. Sounds odd. Works anyway. A warm-to-hot bath for 20–30 minutes after an easy run raises core temperature enough to drive real adaptation.
One honest caveat. This is uncomfortable on purpose — but it should never be dangerous. Stop if you feel dizzy or sick. Don't run heat sessions when you're already run down or fighting something. The goal is stress, not harm.
You don't need Mallorca to prepare for Mallorca. You need to get hot, on purpose, a few times before you go.
Race-week acclimatisation if you arrive early
If you can get to the race 5–7 days before, your body keeps adapting on site — for free. Use it.
Train easy in the warmest part of the day a couple of times. Keep it short. You're not training — you're exposing yourself. Anything hard in the heat this close to race day costs you more than it gives. And practise drinking on the move at the temperature you'll actually race in, not the temperature you trained in at home.
I arrived in Alcudia two weeks early — not to rest, but to prepare properly. If you want the honest version of what a full week of Mallorca heat does to your body and training load, I wrote the whole thing down.
Most age-groupers, though, arrive one or two days before. That's completely fine. It just means the work you did at home matters more.
Pacing and hydration adjustments for race day in heat
Pace by feel and heart rate — not by the power targets or splits you trained for at home. Give yourself permission to be slower. Slower and finishing beats faster and walking, every single time.
Start the run more conservatively than you think you need to. The heat compounds. What feels easy at kilometre 2 is only survivable at kilometre 16 if you banked patience early.
Drink to a plan, not to thirst — in the heat, thirst arrives too late to save you. Electrolytes, not just water. And use every aid station. Ice down your neck. Pour water over your head. Walk through properly if that's what it takes to drink. A 30-second walk at each station is not failure — it is strategy. I've watched athletes blow up in the final 5km because they were too proud to walk for half a minute.
Walk breaks are not failure. Especially in the heat.
What Alcudia taught me — and what I'm doing right now
Here's the honest part. Alcudia never gave me the heat I prepared for. It gave me a storm forecast and a cool, grey, windy day instead. And I'll admit it — standing on that dry descent, part of me was relieved.
But it taught me something I now repeat to every athlete I coach. You prepare for the race day you might get — not the one you hope for. The heat work I did wasn't wasted. It just wasn't needed that day.
If you've got a warm race on the calendar, the heat plan belongs inside your training months out — not bolted on in the final week. That's what structured coaching for athletes preparing for destination races is for: building the unglamorous things into the plan before they decide your day.
Heat shouldn't be the thing that decides your race. Preparation decides it.
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