RT Journal Article SR Electronic T1 Interval and continuous training are similarly effective in chronic obstructive pulmonary disease 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 155 OP 156 DO 10.1136/bjsm.2010.083097 VO 45 IS 2 A1 Mark R Elkins A1 Tiffany J Dwyer YR 2011 UL http://bjsm.bmj.com/content/45/2/155.abstract AB