He was introduced to the discipline in 2005 by his brother Jonah Mayfield. In early 2008, after releasing a sponsorship video, he was recruited to be part of the Urban Freeflow performance team.
Later in the same year he took part in the Barclaycard World Freerun Championships, under the nickname G-Force, where he reached the final, but injured his ankle at the end of his run attempting a double sideflip. He finished in 5th place.
- "YouTube - George Mayfield Sponsorship Video" (2008)
- "YouTube - Parkour/Freerunning - George Mayfield" (2009)
- "Welcome to RedBull - Red Bull Art of Motion 2009 - Athletes". Redbull.at
- "Barclaycard World Freerun Championship » Blog Archive » George ‘G-Force’ Mayfield - UK". Worldfreerun.com
- "UF Team | Urban Freeflow ® Official Freerun/Parkour Site". Urbanfreeflow.com
- "George: One Year And Counting | Urban Freeflow ® Official Freerun/Parkour Site". Urbanfreeflow.com
- "YouTube - George Mayfield Sponsorship Video". Youtube.com
- "barclaycardfinals.jpg (JPEG Image, 402×303 pixels)". Imageshack.us