RT Journal Article SR Electronic T1 Mark Batt 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 7 OP 7 DO 10.1136/bjsm.2006.031880 VO 41 IS 1 YR 2007 UL http://bjsm.bmj.com/content/41/1/7.abstract AB