World doping body takes aim at NFL after Peyton Manning’s alleged positive test
Wada describes the allegations that the Denver Broncos quarterback took human growth hormone as ‘very concerning’

The World Anti-Doping Agency (Wada) on Monday described allegations made in an Al-Jazeera report that Denver Broncos quarterback Peyton Manning took human growth hormone (HGH) as “very concerning” and has urged “increased collaboration” with sports leagues in the United States.
Any investigation by Wada should begin with an independent one into their own practices, including the scientific basis for their tests and governance
Though Manning has vehemently denied the allegations and the source of the Al-Jazeera report has since recanted the claims he was shown making in the film, Wada says that it expects a careful investigation by the relevant authorities.
The December 27 investigative documentary ‘The dark side: The secret world of sports doping,’ linked well known players from the National Football League (NFL) and Major League Baseball (MLB) with performance enhancing drugs.

David Howman, director general of Wada, said he was nevertheless taking the report seriously and took aim at the NFL.
“Al-Jazeera's allegations are very concerning, particularly as it relates to the NFL's and MLB's testing programs,” Howman said in a statement.
While the documentary’s makers and its critics have clashed over the validity of the allegations, the report has nevertheless pushed concerns of illegal performance enhancements in America’s most popular sports leagues into the spotlight once again.
Athletics, cycling and baseball have all suffered huge embarrassment over doping in the past decade and Al-Jazeera’s report at the very least has highlighted long-running differences between Wada and NFL in their anti-doping strategy.