RT Journal Article SR Electronic T1 “You don't have to …”: walking to a healthier nation JF British Journal of Sports Medicine JO Br J Sports Med FD BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine SP 79 OP 80 DO 10.1136/bjsm.34.2.79-a VO 34 IS 2 A1 Andrew Tannahill YR 2000 UL http://bjsm.bmj.com/content/34/2/79.2.abstract AB