Mark Verstegen, founder and president of Athletes' Performance, has worked with some of golf's biggest names, including David Leadbetter and his world-famous golf academies, Phil Mickelson, Billy Mayfair, and Candie Kung. A world-renowned performance coach, consultant, and motivational speaker, he lives in Scottsdale, Arizona.
Pete Williams is the author or coauthor of numerous books, including Core Performance Women and the Rodale titles: Core Performance, Core Performance Essentials, Core Performance Endurance, and Fun Is Good. He lives in Safety Harbor, Florida.