Charles Sly recanted the statements he made to Al Jazeera's undercover reporter about banned substances delivered to Peyton Manning and other professional athletes.

But Sly spoke with detail and expertise about doping and mentioned the names of Manning, Ryan Howard and others.

Nearly all of the athletes Sly named are clients of Jason Riley, who is a fitness trainer based in Sarasota, Florida.

Sly is a business partner of Riley's and when Sly applied for a pharmacist's license in Florida, he used Riley's home address.

Riley’s work as a trainer is so celebrated that he was called “baseball’s M.V.P. of the post-steroids era” by Men’s Fitness magazine.

Riley's most famous client, the man whose career he was credited with reshaping and saving from mortality’s shadow, was Derek Jeter. In 2010, a few years into Riley’s makeover, The Daily News proclaimed: “Derek is turning back the clock at short.” ESPN declared that Riley had “dumped the Captain into a hot tub time machine” and turned him into a 25-year-old.

Riley and Sly founded Elementz Nutrition, a nutritional supplement company whose website and Facebook page feature many of the athletes Sly mentioned on camera.