'So proud': Twin who gave up Olympic spot to sister

Lanny Barnes (left) didn't win a medal in Sochi, but the story of the Barnes sisters have touched many hearts around the world.

Tracy Barnes gave up her dream spot on Team USA for her sister Lanny, and then surprised her by watching from the sidelines in Sochi. 

“I was just holding back tears,” Barnes told TODAY’s Natalie Morales of watching her sister compete.

Video:  Olympian thanks her sister for making it possible

The pair have trained side by side for 15 years, competing in the biathlon event, a sport that combines cross-country skiing and shooting.