What’s the weirdest thing you learned this week? The Weirdest Thing I Learned This Week hits Apple, Spotify, YouTube, and everywhere else you listen to podcasts every-other Wednesday morning. A marathon swim is any event over 6.2 miles or 10K in a river, lake, ocean, really any body of water that is not a pool. Modern marathon swimming was born in 1875, when Matthew Webb became the first person to successfully swim across the English Channel. It varies person to person, but most swimmers will eat every 30 minutes.