Alysia Johnson is carried off the track after competing in a women's 800 meters heat at the U.S. Olympic Track and Field Trials in Eugene, Oregon June 27, 2008. REUTERS/Steve Dipaola (UNITED STATES) (BEIJING OLYMPICS 2008 PREVIEW) 

Alysia Johnson of Canyon Country, California smiles after winning the women's 800 meter run finals at the USA Outdoor Track and Field Championships in Indianapolis June 24, 2007. REUTERS/Brent Smith (UNITED STATES) 

Alysia Johnson of Canyon Country, California stumbles across the finish line tape to win the women's 800 meter run finals at the USA Outdoor Track and Field Championships in Indianapolis June 24, 2007. REUTERS/Brent Smith (UNITED STATES) 

Alysia Johnson (R) of Canyon Country, California edges Hazel Clark of Knoxville, Tennessee at the finish line in the women's 800 meter run finals at the USA Outdoor Track and Field Championships in Indianapolis June 24, 2007. REUTERS/Brent Smith (UNITED STATES)