British designer Stella McCartney brings a whole new meaning to 'Jog on!'. Crafted from grey wool and cotton, these elasticated jogging trousers are functional, fitted and ready to take on just about anything. Sassy Stella. Featuring an elasticated drawstring waist, a straight leg, side slit pockets and gathered ankles. POSITIVELY CONSCIOUS: We’ve joined forces with ethical agency Good On You to give you the power to choose positively. This piece is from a brand that scores well on their key criteria.