LEFT-VENTRICULAR RESPONSE IN HEALTHY-YOUNG MEN DURING HEAVY-INTENSITYWEIGHT-LIFTING EXERCISE

We examined cardiac volumes (using echocardiography), intra-arterial b lood pressure (BP), and intrathoracic pressure (ITP) in healthy males performing leg press exercise to failure at 95% of their maximum dynam ic strength. Compared with preexercise, during the lifting phase of ex ercise, end-diastolic volume (EDV; 147 +/- 8 to 103 +/- 7 ml) and end- systolic volume (ESV; 54 +/- 5 to 27 +/- 4 ml) decreased (P < 0.05); h eart rate (82 +/- 6 to 143 +/- 5 beats/min), systolic BP (160 +/- 6 to 270 +/- 21 Torr), diastolic BP (91 +/- 2 to 183 +/- 18 Torr), ITP (0. 8 +/- 0.8 to 57.8 +/- 24 Torr), and peak systolic BP/ESV (SBP/ESV; 3.0 +/- 0.3 to 11.0 +/- 1.5 Torr/ml) increased (P < 0.05); and stroke vol ume decreased (94 +/- 3 to 77 +/- 4 ml; P > 0.05). Full knee extension was associated with most values returning to preexercise levels excep t for ESV (38 +/- 7 ml), heart rate (130 +/- 9 beats/min), and ITP (-1 2.5 +/- 2.1 Torr). During the lowering phase, significant decreases in EDV to 105 +/- 14 ml and ESV to 27 +/- 7 ml were observed with increa ses in systolic BP to 207 +/- 23 Torr, diastolic BP to 116 +/- 8 Torr, and SBP/ESV to 10.0 +/- 2.5 Torr/ml. Stroke volume decreased to 78 +/ - 9 ml (P > 0.05). Thus rapid changes in cardiac volumes, contractilit y, and pressure occur during weight lifting that are related to differ ent phases of the lift.