SEOUL, March 17 -- Your morning jog just got a whole lot. butter.

The viral "butter run" - or as some are calling it, the "churn and burn" - is turning heads (and stomachs) by blending cardio with a kitchen experiment. What started as a quirky idea among trail runners has now snowballed into a full-on social media trend, with runners in from South Korea to Australia joining in.

But this isn't just another random TikTok challenge. It actually has a very specific origin story - and it begins on the trails of Oregon.

Earlier this year, 30-year-olds Libby Cope and Jacob Arnold decided to test a question that sounds like it came mid-caffeine buzz: "Do you think if we ran with this it would turn into butter?"

Instead of overthinking it, the...