Kerri Walsh-Jennings at 21 and 37 (Photos: Jamie Squire/Getty & Ezra Shaw/Getty)

It’s rare to only check in on people once every four years. Even your weird cousin is bound to come to Thanksgiving a little more frequently than that. But in addition to showcasing the best of the best in athletics, the Olympics also provides four-year check-ins on our favorite athletes. And now Buzzfeed has rounded up photos that juxtapose 2016 Olympic athletes with the way they looked at their very first games.

Some haven’t aged too much: 19-year-old swimming superstar Katie Ledecky still looks reasonably the same as she did when she was a 15-year-old gold medal winner in London in 2012. But 37-year-old volleyball player Kerri Walsh-Jennings and 31-year-old swimmer Michael Phelps have made significant transformations since their debuts at the 2000 Sydney Olympics when they were 21 and 15, respectively.

[via Buzzfeed]