RT Journal Article SR Electronic T1 Commentary 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 255 OP 255 DO 10.1136/bjsm.31.3.255 VO 31 IS 3 A1 M Barnes YR 1997 UL http://bjsm.bmj.com/content/31/3/255.abstract AB