RT Journal Article SR Electronic T1 Withdrawn JF British Journal of Sports Medicine JO Br J Sports Med FD BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine SP 383 OP 383 DO 10.1136/bjsm.2011.084038.206 VO 45 IS 4 YR 2011 UL http://bjsm.bmj.com/content/45/4/383.1.abstract AB