Climate change threatens future marathon records, study warns

Rising global temperatures are making it increasingly difficult for runners to break marathon records, according to new research by US-based non-profit organisation Climate Central.

The study found that higher temperatures “have made record-breaking runs in some races nearly impossible” and predicted that optimal running conditions—defined as 4°C for men and 10°C for women—will become less likely in 86% of 221 global marathons by 2045, BBC writes. 

Recent major races have already been affected by warmer-than-usual weather. The Berlin Marathon was held in an unseasonal 24°C in September, while both the Tokyo and London Marathons saw temperatures above 20°C during their spring editions.

World Athletics president Sebastian Coe recently suggested that endurance events such as the marathon may need to be staged separately, at different times of year, during competitions like the World Athletics Championships to protect athletes from unsafe heat.

Elite runners have voiced growing concern about the impact of climate change on performance. Mhairi Maclennan, the fastest British female finisher at the 2024 London Marathon, said:

"At the elite level conditions make or break a performance. We train day in, day out for years and manage every aspect of our lives to race our best, only for that elusive target to drift further away as ideal temperatures become rarer. Climate change isn't just about races becoming harder; it's about knowing that record-breaking performances could soon be out of reach if conditions keep getting hotter."

According to Climate Central’s analysis, Tokyo currently offers the highest chance of ideal temperatures for elite male runners (69%) but is projected to experience the steepest decline in optimal conditions by 2045.

The men’s marathon world record of two hours 35 seconds was set by the late Kelvin Kiptum in Chicago in 2023, while Ruth Chepngetich established the women’s world record at the same event in 2024. Chepngetich was later banned for three years after admitting to anti-doping violations.

Over the past seven years, the men’s world record has been reduced by two minutes and 22 seconds, with much of the improvement attributed to advances in shoe technology.

Former women’s world record holder Catherine Ndereba said:

"Climate change has altered the marathon. Dehydration is a real risk, and simple miscalculations can end a race before it begins. Every step now carries a message - that if we don't take care of our planet, even our strongest strides will fall short."

By Sabina Mammadli