THE RELATIONSHIP OF EARLY VERSUS 2-MINUTE RECOVERY ECHOCARDIOGRAPHIC VALUES FOLLOWING MAXIMAL EFFORT RESISTANCE EXERCISE

Two-dimensionally directed M-mode echo-cardiography was used to measure left ventricular systolic function following maximal dynamic resistance exercise (RE). Upright measurements were made from the long axis parasternal view at rest, 20 seconds post-exercise, and two minutes post-exercise. Thirty-two successful studies were recorded from a total of 37 trained and untrained male subjects who were heterogeneous as to mode and level of training. Resistance-trained men averaged 3.8 +/- 2.4 yrs of training for 9.7 +/- 3.0 hr/wk, and endurance-trained men averaged 6.4 +/- 3.9 yr of training at 202.5 +/- 112.6 km/wk of cycling, running, and swimming. The trained men competed at the state or regional level. The RE protocol (knee extensions) was performed as follows: [GRAPHICS] The RE protocol produced significant post-exercise reductions in end-systolic diameter (p < 0.0002) and significant post-exercise increases in fractional shortening (p < 0.0001) and velocity of circumferential fiber shortening (p < 0.0002). The inotropic variables were still significantly different at two minutes post-exercise compared to the 20 second measure, suggesting that early recovery is a better approximation of maximal values. Velocity of circumferential fiber shortening at 20 seconds and two minutes was significantly correlated (r = 0.39) and fractional shortening was not (r = 0.34) at these serial measurement times. This study indicated that velocity of circumferential fiber shortening was a better index than fractional shortening of maximal performance at two minutes of recovery, but since all correlations are low, neither variable at two minutes post-exercise was suitable as an index of maximal performance. Further, because of phasic changes in cardiac loading during and immediately post-resistance exercise, extrapolation to maximal values may be tenuous.