This article by Cynthia Gorney in the June 2005 issue of Runner's World touches on a delicate issue. The subtitle is a little more revealing: "Ever wonder how much faster (or slower) you'd run if you were the opposite sex? Janet Furman Bowman may be the only runner in America who knows."
The running performance change has been over two minutes per mile slower as Janet than he/she was as Jim. The person who runs as Janet today once ran a 5:05 mile, 17:02 5K, and a 3:01 marathon. The article covers the changes he and his friends in the Tamalpa Running Club in Marin County, California went through as he changed from a male to a female.
In this day of drug testing and drug evasions, this article was enlightening in showing another side to the story. Usually, it is a male or female taking hormone treatments to boost their performance. Here the sexual transformation from a male to a female was dealt with in a sensitive manner.
For the full story, read here.