Pained Felix still out to punch double ticket for Rio

Runner Allyson Felix poses for a portrait with the U.S. flag at the U.S. Olympic Committee Media Summit in Beverly Hills, Los Angeles, California March 7, 2016. REUTERS/Lucy Nicholson

EUGENE, Oregon (Reuters) - Already America's most decorated female sprinter, Allyson Felix launches the most difficult challenge of her career this week.

Despite an ankle sprain that pains her when she runs, the 13-times global champion hopes the July 1-10 U.S. Olympic trials bring her a double ticket to Rio where she hopes to become the third woman to win a 200-400 metres double at the same Olympics.