Dutch runner Sifan Hassan has long been revered for her versatility in mid- and long-distance running, but now she is set to go the extra mile — or rather, 26.2 miles — at the Paris Olympic Games.

While eyeballs were on the US Championships and Jonah Koech's upset 1500m, Under Armour was quietly putting together a string of stellar performances over the 1500m distance. In one swoop, Under ...