No matter the sport, cheaters have always stayed one step ahead of those trying to catch them by doping with as-yet undetectable products. But what if authorities didn't need to determine what the products were, only what the specimin should look like if unaltered by any drug? Meet the biological passport, and Travis Tygart, the man who has successfully routed out two of sports' most defiant cheats, Lance Armstrong and Marion Jones, neither of whom had ever tested positive.
Not a subscriber? Click here to sign up for the daily PDF or alerts.
