For the two out of the last three years, one of those students drawn to the joy of competing under your school name while hanging out with your friends is Missy Franklin, a five-time medalist in the 2012 London Olympics who, between celebrity appearances and a continuing Olympic-level swim schedule, goes to school and swims for Regis Jesuit, a private high school in the Denver area.

FORBES: Olympian Missy Franklin Gives Up Millions To Validate The High School Sports Experience

She says she chose Lake Ontario for her swim because it's one of the hardest open-water swims in the world, and she wanted to "accomplish something difficult" for children who fight cancer.

CNN: 14-year-old swims solo across Lake Ontario

Nearly 50 other swimmers have completed the swim since then, but Annaleise is the youngest, according to Solo Swims of Ontario, a non-profit group that monitors the safety of long-distance swims.

CNN: 14-year-old swims solo across Lake Ontario

She swims six days a week now with members of the Golden West Swim Club, a team made up of kids less than half her age.

CNN: STORY HIGHLIGHTS

During the swims, the researchers measured the volunteers' oxygen consumption, rectal temperature, swim speed and angle, and stroke rate and length.

BBC: Cold water increases drowning risk