The announcement comes after two recent uproars surrounding convicted dopers.
94 percent of the field took part in the 10-question survey.
We caught up with the recent winner of the Western States Endurance Run.
Check out these great shots from the 2015 race!
The Nike Trail Athlete ran the prestigious 100-mile race for the first time this year.
The Western States 100 provides the perfect opportunity to research the affects of ultrarunning on the body, reports Allison Pattillo.
From racer to race director, Craig Thornley is taking it all in stride.
Check out these great shots from the most celebrated 100-miler in the world!
The runners were filmed with a 10-pound camera.