RT Journal Article SR Electronic T1 Rating of perceived exertion as a predictor of the duration of exercise that remains until exhaustion 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 623 OP 624 VO 42 IS 7 A1 T D Noakes YR 2008 UL http://bjsm.bmj.com/content/42/7/623.abstract AB