Not only is Chris Mosier the first transgender athlete to make the U.S. Olympic men'steam, but he is also the first transgender athlete to appear in a Nike commercial, so yeah. He's basically breaking ground all over the place these days.

Mosier began his transition in 2010, and joined the men's national team as a duathlete in 2015. This is his first Olympics.

"Being the first trans man on a U.S. men's national team was a dream come true for me," Mosier told Nike. "It's just such an amazing opportunity—and an amazing opportunity for other people to see themselves reflected in someone succeeding in sports as a trans man."