Think a journey from Alaska to New Zealand sounds like a killer of a red-eye flight?

The 7,200-mile trek wouldn't be much fun for a human sitting comfortably in a 747—but chances are, it's a much bigger challenge for the bar-tailed godwit, a type of wading bird that just completed the round-the-world flight in eight sleepless days and nights, without stopping for food or water. Scientists who tracked the birds' flight say that the journey is the longest single trek for any bird on Earth.

"There is something special going on here. For a vertebrate this kind of endurance is just extraordinary," Theunis Piersma, a biologist from the Netherlands' University of Groningen who worked on the study, told the Guardian.

Though researchers were aware that the bar-tailed godwit was capable of flying far, the extent of their migratory path was uncertain until this year, when scientists decided to track the birds with satellite transmitters. The birds were airborne for up to nine days, and flapped their wings without stopping for the entire journey. Such strenuous exercise would have made them burn energy at about eight times their basic metabolic rate (BMR)—while even Olympic-level athletes max out at five times their BMRs.

"Lance Armstrong would be no competition for these birds," said Piersma.