The American record-holder says it was her farewell to high-level marathons.
One study suggests that runners who rely on less muscle activation actually go faster.
Galen Rupp and Mary Cain are two distance stars to check out.
Men's, women's 800m winners triumph in quick fashion on the final day of the USA Outdoor Track & Field Championships.
The Olympic silver medalist booked his ticket to Moscow.
It was a likely move for the University of Oregon standout.
He wants his athletes to have fresh legs going into their races.
He dusted the field of 20 runners in the men's 5000m.
The American runners have excelled at Hayward Field in the past.
The Olympic silver medalist prevailed with a huge kick.