As a species, we may be logging the fastest marathon times we’ll ever make right now. For years, marathon times have been ticking downward. But climate change may ruin that trend, as it will ruin everything else humanity has built. The problem: We don’t run so well in the heat.

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This trend isn’t kicking in a noticeable way quite yet. But in a new study published in PLoS ONE, Boston University researchers found that by 2100, they’ll have a 95 percent chance of detecting a “consistent slowing of winning marathon times,” according to BU. 

There is the option of just edging race times earlier, to avoid the hottest times of the day. Marathon runners are intense enough about their sport that we can imagine them starting out at 2 a.m. in order to keep their times down. Or perhaps we’ve simply reached the peak of human accomplishment in this area, and everyone from here on out has a good excuse.

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