RT Journal Article SR Electronic T1 Heartbeat: Is biologic age best defined by exercise capacity? JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 409 OP 410 DO 10.1136/heartjnl-2016-309463 VO 102 IS 6 A1 Otto, Catherine M YR 2016 UL http://heart.bmj.com/content/102/6/409.abstract AB