Differential Effects on Regional Pulse Wave Velocity and Augmentation Index Following Maximal Exercise in Healthy Young Men

Nine young normotensive healthy males (24.6± 3.7 years; 75.4± 10.2 kg) MAP = 91 ± 6 mmHg were studied for 1-hour following an incremental ramp protocol to VO2peak (56.2± 10.5 ml/kg/min) on an electronically braked cycle ergometer. Blood pressure was assessed via an automated blood pressure monitor (Datex-Ohmeda, Finland). Regional limb pulse wave velocity (PWV) was determined simultaneously in the left arm and leg by oscillometry (QVL P84, UK) whilst contemporaneously determining central aortic stiffness (AIx) via aplannation tonometry (Sphygmocor, Atcor Medical, Australia). The operator index, which is an estimate of quality of the SphygmoCor derived waveforms, was above the recommended level with an average index of andgt;80%. Following mathematical confirmation of distribution normality using the Shapiro-Wilks test data were analysed with a repeated measures ANOVA and post-hoc Bonferroni-corrected paired samples T-tests. During exercise there was an intensity-related increase in MAP, heart rate and pulse pressure (Pandlt;0.01). Exercise decreased both systolic blood pressure across the 60-minute recovery period (Pandlt;0.01) and MAP in the initial recovery from exercise (Pandlt;0.05). Upper limb PWV was reduced following exercise (Pandlt;0.05) whilst lower limb PWV was unchanged. AIx was elevated at the termination of exercise (Pandlt;0.05) but did not decrease below resting levels in the recovery period. These results indicate that in active healthy individuals acute exercise induces a systemic hypotension and increased arterial compliance in the upper limb vascular bed but not the lower limb vascular bed. Furthermore, estimated aortic stiffness and central pressure appears to remain un-modified in the recovery from exercise. Hence there are clear differential responses in central and peripheral large artery haemodynamic recovery from exercise.