Expanded blood volumes contribute to the increased cardiovascular performance of endurance-trained older men

volumes contribute to the increased cardiovascular perfor-mance of endurance-trained older men. J. Appl. Physiol. 85(2): 484–489, 1998.—To determine whether expanded intra-vascular volumes contribute to the older athlete’s higher exercise stroke volume and maximal oxygen consumption (V̇O2max), we measured peak upright cycle ergometry cardiac volumes (99mTc ventriculography) and plasma (125I-labeled albumin) and red cell (NaCr51) volumes in 7 endurance-trained and 12 age-matched lean sedentary men. The ath-letes had,40 % higher V̇O2max values than did the sedentary men and larger relative plasma (46 vs. 38 ml/kg), red cell (30 vs. 26 ml/kg), and total blood volumes (76 vs. 64 ml/kg) (all P, 0.05). Athletes had larger peak cycle ergometer exercise stroke volume indexes (75 vs. 57 ml/m2, P, 0.05) and 17% larger end-diastolic volume indexes. In the total group