Postexercise Arterial Compliance and Hemodynamic Responses to Various Durations and Intensities of Aerobic Exercise.

The purpose of this study was to determine the effects of various aerobic training protocols using different intensities and durations on arterial compliance and hemodynamic responses. Seventeen male subjects (age = 23.1 ± 2.8 years) performed a maximal oxygen consumption (V̇o2max) test, followed by 3 randomly assigned exercise test sessions, each on a separate day. At the beginning of each test session, pre-exercise baseline assessments of arterial elasticity, hemodynamic variables, and pulse wave velocity (PWV) were performed after a 10-minute rest. After baseline measurements, participants performed either a bout of aerobic exercise on a treadmill for 60 minutes at 65% of V̇o2max (60min); 20 minutes at 40% of V̇o2max (20min); or for 20 minutes at 40% of V̇o2max with blood flow restriction (BFR; 20min-BFR). All baseline measurements were repeated at the completion of each testing session. Significance for this study was set at p = 0.05. The 60min session resulted in significant increases in small artery elasticity (SAE) compared with the 20min-BFR session (p < 0.03) and decreases in both systemic vascular resistance (SVR) and total vascular impedance (TVI) compared with both 20min sessions (p < 0.01). The carotid to radial PWV was significantly lower after both the 60min and the 20min-BFR sessions compared with the 20min session (p < 0.02). The findings indicate that the duration and the intensity of exercise are important factors for improving SAE, SVR, and TVI. In addition, 20min-BFR at 40% V̇o2max may result in site-specific modifications in PWV that is comparable with those seen after 60 minutes of exercise at 65% V̇o2max. [ABSTRACT FROM AUTHOR]