At this week’s world championship, the women’s record holder who once feared a 5K will try to top her own 144-hour distance – and beat the US men’s mark

While many teachers head back to school this week, middle-school math teacher Megan Eckert will be 5,000 miles from her classroom in Santa Fe, New Mexico. She has a good reason to miss a few classes: she’ll be competing at the Global Organization of Multi-Day Ultramarathoners World Championship.

On Thursday, more than 100 runners will gather on a start line in Balatonfüred, Hungary, and attempt to run as many miles as they can in six days.