Runners have squeezed in miles in some strange places — parking garages, hotel hallways, airport terminals before a gate change. But Dom Stroh, founder of the travel-run community RETREATURE, has taken it further than most would dare, or frankly consider: he ran a 5K inside an airplane bathroom at 35,000 feet.

The video, posted to Instagram with the caption “MILES high club,” shows Stroh setting up a camera in the corner of the lavatory, flashing his Strava watch to start the timer, then looping around the tiny space — stepping up onto the toilet seat and circling repeatedly — until he hit 5.53 kilometers. The flight was roughly 11 hours long. His finishing time: 59 minutes and 32 seconds, at a 10:46 per kilometer pace.