Why global warming could be ‘rewriting race history’ at major marathon events

Runners compete in last year's New York City Marathon. Craig T Fruchtman/Getty Images

Runners already face a daunting challenge when they line up at the start of a marathon , but they might increasingly find themselves with another obstacle to reckon with: global warming .

A new study claims that rising temperatures around the world will make it harder for elite athletes to break the marathon world record, or for recreational runners to hit their target times.

Of the 221 races analyzed in the report from Climate Central released last week, 86% of them are less likely to have optimal racing conditions for runners by 2045.

That includes last Sunday’s New York City Marathon and the other six major marathons around the world — London, Berlin, Tokyo, Chicago, Boston, and Sydney.