CNN  —  Kelly Catlin and Ellie Soutter never met, but they had a lot in common. Both were commanding athletes: Catlin, a US track cyclist, was a three-times world champion and Olympic silver medalist, and Soutter, a snowboarder, was tipped to be one of Team Great Britain’s strongest contenders for the 2022 Winter Olympics, having already won a bronze medal at the 2017 European Youth Olympic Festival. Both were incredibly smart – Catlin was studying for a master’s degree in computational and mathematical engineering at Stanford University, while Soutter learned to speak French in about six months, according to her father. At times they almost seemed superhuman. In 2013, after…