How to cool and hydrate like a world champion
Canadian race walk world champion Evan Dunfee shared his tips and tricks for handling the hottest and most humid conditions on race day
Nick Iwanyshyn
Three weeks ago, Richmond, B.C.’s Evan Dunfee stormed to 35K race walk gold at the 2025 World Athletics Championships in Tokyo. Now, the athlete shares how he conquered brutal conditions–temperatures soaring above 25 C, with humidity above 90 per cent–to claim his first world title by more than 30 seconds, with a torn hamstring.
The conditions in Tokyo were so bad that World Athletics president Seb Coe admitted changes to the traditional competition schedule may be necessary at future major championships, moving the marathon and race walk events away from the traditional schedule after some high-profile athletes withdrew from their races.
Heat acclimation
Dunfee’s first tip for tackling the high temperatures is getting used to it. Heat acclimation requires warm weather exposure for 10 to 14 days ahead of the event, which helps the body adapt to improve sweat rate and thermal sensation (how hot you feel). “I was a little tight on this for the 35K, partially because my main race focus had been the 20K–which is unfortunate in retrospect,” Dunfee, who withdrew from the 20K due to a torn hamstring in the 35K event. The athletes also completed 25- to 30-minute sauna sessions three times a week for passive heat exposure during their altitude training camp in St. Moritz, Switzerland. “The science is a little less settled here on whether that is impactful,” Dunfee admitted.
Pre-race cooling
On race day, the race walkers aim to have their core temperatures as low as possible when the race begins. “This gives our body the biggest buffer possible to work with as our core temp rises throughout the race,” Dunfee explained. “We do a minimal warmup, followed by time in the cold-plunge pool. We want it as cold as possible without shivering (shivering creates heat, so it is counter-intuitive).”
From experience, Dunfee says he has learned his feet get soft and more prone to blisters when they are wet; now, he is sure to keep his feet out of the water during these plunges. After the cold tub, the athletes put on ice vests and cold towels until the race starts.
Mid-race cooling
The final element, Dunfee shared, is slowing the speed at which their bodies heat up mid-race. “I use ice scarves and ice cold towels around my neck, which I swap out every two to four kilometres, depending on how quickly they’re melting,” he said.
Dunfee also uses cold water, ice or sponges on his skin to keep it as cool as possible. “This helps maintain a large gradient for sweating and reduces how hot you feel. When it is humid as it was in Tokyo, this skin-cooling is a very important element.”
Hydration and pacing
Other important factors for performance in the heat and humidity, Dunfee says, are hydration and pacing. He says he significantly lowered the concentration of his sports drink from training in St. Moritz (where it was 10-15 C) to what he was drinking in Tokyo, so he could consume more fluid while still maintaining the same carbohydrate intake (80g per hour).
But no matter how well you cool and hydrate, pacing is still critical. “A perfect cooling and hydration plan cannot overcome poor pacing,” Dunfee said. “In hot weather, you’re much more susceptible to tipping over your red line by going out too hard.”
Dunfee and his team calculated his expected race pace based on the conditions in Tokyo, determining he’d likely be going around 10 seconds slower per kilometre than his world record pace in March. The other racers, who went out much faster, ended up fading hard and finishing much further back, while Dunfee stuck to his plan. The Canadian also analyzes data collected by his CORE sensor, a device that measures core temperature, to understand how it affected his race.
Post-race, the primary focus is simply: lower your core temperature and re-hydrate.
All races, Dunfee says, require consideration for the conditions, and even at non-extreme temperatures, pacing will likely need adjusting. “When it comes to cooling strategies, it’ll depend a lot on what you have access to,” he said. “It doesn’t have to be fancy–my neck scarves are women’s stockings filled with ice, with shoelaces tied around the ends.”
