I recently came back from running the Melbourne Marathon in Australia last month, where the race-day temperatures were around 8 to 15 degrees C with 70% humidity.

Based in Singapore where it is always very hot and humid (averaging 28-32 degrees C with 90-100% humidity), I have always wondered how training in such hot climates can have an impact on race performances in cooler climates and whether tropical training can help or hinder race performance in temperate weather. 

So I caught up with Ben Pulham, 45, endurance coach and founder of Coached, for his take on this topic.

Ben Pulham.
Credit: Coached

Many runners who have had the opportunities to run in cooler climates, know how much more challenging it is to run in the heat and humidity of Singapore, me included. 

This difference is real, and not imaginary. Said Ben, “Heat changes the rules. In the tropics, your body has to work harder just to keep you from overheating, so your heart rate climbs fast and stays high. You sweat more. You dehydrate faster. Performance drops long before your legs actually gives out.”

He continued, “In cool weather, the opposite happens. Your body stays comfortable, blood flow goes to the working muscles instead of the skin, and effort feels lighter at the same pace. It becomes a truer measure of your actual fitness.”

As a result, pacing in temperature weather should be adjusted accordingly, it should also be realistic to your fitness level. 

Said Ben, “Ease into it. Cool weather can trick you into thinking you’re Superman. The first few minutes feel too good. If you go out too fast, you’ll pay for it later.”

He added, “run by feel for the first third, watching pace and heart rate for a combination of effort. If two out of three align, you’re probably good. Once you settle in, then you can roll.”

That said, there are definitely some performance advantages for runners who train in tropical conditions but race in temperate climates. 

Said Ben, “Heat builds resilience. It teaches your body to regulate temperature better and expand plasma volume. When you step into cool weather, those adaptations help you hold effort longer.” 

He added, “But the reverse is not as helpful. Cool weather training does little for you when you return to the heat. If anything, it can leave you underprepared for the strain.”

With regards to hydration and fuelling, you need to fuel much more aggressively in tropical weather. So this means you’d need less hydration and fuel on race day in temperate weather compared to your training runs. 

Said Ben, “Heat demands more. More fluid, more sodium, more attention. Cool weather is simpler. You still need carbs, you still need to drink, but the margins are wider. You’re not constantly fighting dehydration. You can focus more on the work and less on survival.” 

However that said, Ben pointed out that not hydrating enough is one of the most common mistakes that runners who train in the tropics might make on race day in temperate weather.

Ben explained, “There are three big mistakes. These are:

• They start too fast
• They overdress or underdress
• They stop fuelling because they don’t feel thirsty.” 

Continued Ben, “To avoid all three, do this. Start controlled. Wear more or less – I personally like a delayering approach if you’re unsure. Fuel on schedule, not on feeling.”

Ben would recommend to dress for the middle, and not to the extremes even if you’re feeling cold. 

He said, “Arm sleeves or a thin jacket usually do the job. Gloves help more than heavy layers. A beanie or headband is nice but optional. Try to keep it simple.”