The 37-year-old comedian revealed that the special equipment used while taking part in the sporting session resulted in him getting hurt recently.
3 August 2012 He said: "What happened was this foot here has become hurt from what I can only describe as kicky boxing. I call it kicky boxing. Kickboxing sounds so aggressive. I've been doing, like, kickboxing.
"But it's not like I kicked someone so hard that a bit of my foot fell off. It's that there was abrasiveness caused by the foot pad. It's essentially a rug burn."
As a result the star has been walking around the street with no shoes on to help deal with the fragile area.
He commented on general footwear: "I mean, shoes are, in themselves, an oddity and addition."
Russell isn't new to the type of exercise which infuses fighting moves and was spotted working out with a personal instructor in 2010.
He was believed to have taken up the practice to prepare for his wedding to ex-wife Katy Perry.
His divorce to the 'Firework' singer was recently finalised after he filed for a legal separation in December last year.