Kourtney Kardashian shows off toned tummy as she stepped out of a studio in sports bra and black leggings

Kourtney Kardashian 37, flaunts her stunning toned tummy on Monday as she left a studio in Calabasas, California. The mother of three looked incredible in a black sports bra and black leggings which she matched with a pair of grey trainers. Check out more photos after cut...