![\"Swiss](\"https:\/\/www.japantimes.co.jp\/japantimes\/uploads\/images\/2026\/08\/19\/558213.jpg\" "\\"Swiss")
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\n Swiss long-distance runner Fabienne Schlumpf in action during European Championship marathon in Birmingham, Britain, on Sunday.
\n | REUTERS\n <\/p>\n
There is a physiological basis to this approach, says Christopher Minson, a professor of human physiology at the University of Oregon who studies exercise and thermoregulation. The human body has \u201can incredible ability to adapt to heat,\u201d he says, and many of these changes are protective. \u201cBy far the best thing a runner can do in terms of safety and performance is to get acclimated to the heat.\u201d<\/p>\n
Minson suggests athletes start at least a month in advance of a race, but ideally make some heat exposure a regular part of their training routine. This could include a post-training sauna or hot tub, scheduling low-effort training during the warmer part of the day and doing some training in a heated room. He says athletes shouldn\u2019t use critical training sessions, such as interval days, for heat exposure.<\/p>\n
Another factor for runners to consider is how the peak heat window has shifted, says Emma Kirk-Odunubi, a sports scientist and running coach in London. \u201cIt used to be that 12 to 2 p.m. was the hottest time, but now that\u2019s extending all the way past 5 or 6 p.m. sometimes, and people are needing to readjust their schedules completely.\u201d<\/p>\n
This is why athletes in the unrelenting heat of Phoenix have long been night owls.<\/p>\n
QuHarrison Terry, who\u2019s gearing up for the Great World Race, a series of seven marathons on seven continents in seven days in November, says the heat and humidity in Dallas, where he lives, have moved his training toward early evening.<\/p>\n
\u201cIt feels like it\u2019s getting cooler as you go, versus morning runs, where it just keeps getting hotter the longer you\u2019re out there,\u201d says the venture capitalist and tech entrepreneur.<\/p>\n
In Hong Kong, where heat has long been a challenge for outdoor sports, Sylvia Lour, a telecommunications strategist, says the problem has become more pronounced in recent years. During her training for the Berlin Marathon, she skipped group runs that started at 8:45 a.m. on exposed routes, when the sun and heat can be too much.<\/p>\n
Organizational shifts<\/p>\n
Still, even the best preparation can\u2019t account for the weather on race day. Traditionally, runners could count on cool conditions for the fall marathons in Berlin, Chicago and New York, with low humidity and temperatures around 2 C to 13 C. But a recent Climate Central analysis of 221 global marathons suggests these cooler race days are already becoming harder to find.<\/p>\n
Andrew Pershing, who worked on the analysis as the nonprofit\u2019s chief program officer, points to the cancellation of the Twin Cities Marathon because of extreme heat in 2023. Temperatures reached a record-setting 33 C in Minneapolis and St. Paul; organizers moved it to later in the year.<\/p>\n
Last year\u2019s Berlin Marathon also experienced an unseasonal high of about 27 C. That\u2019s 8.3 degrees hotter than normal for late September, Pershing says, an increase \u201cmade at least two times more likely by climate change.\u201d<\/p>\n