Resistance Exercise on Pulse Wave Reflection and Arterial Stiffness Between Trained and Untrained Individuals

Abstract

Pulse wave reflection [augmentation index (AIx), augmentation pressure (AP)], and arterial stiffness [pulse wave velocity (PWV)] are indicative of cardiovascular health. Acute resistance exercise (RE) alters pulse wave reflection, and arterial stiffness, but responses in resistance-trained individuals is unclear. PURPOSE: To examine the responses in pulse wave reflection and arterial stiffness after RE in resistance-trained (RT) versus untrained (UT) individuals. METHODS: Twenty-one (RT: n=14; UT: n=7) individuals volunteered. Pulse wave reflection and arterial stiffness were collected at rest, and 10min following a control, or RE consisting of 3 sets of 10 repetitions at 75% 1-repetition maximum (1RM) on the leg press, lat pulldown, leg extension, chest press and leg curl. A 2x2x2 ANOVA was used to examine group (RT, UT) differences across conditions (RE, control) and time (Rest, Recovery). RESULTS: The groups were similar (p>0.05) for age, height, and BMI, but not weight (p<0.05). The 1RMs for all exercises, except leg extension (p=0.26), were different between groups. At rest, the groups were statistically different for the tension-time index [TTI (RT: 1999±282ms; UT: 2192±209ms, p=0.04)], diastolic pressure-time index [DPTI (RT: 2817±316ms; UT: 3047±171ms, p=0.003)], and PWV (RT: 5.5±0.7m/s; UT: 6.3±0.4m/s, p=0.0001). There were significant time by condition interactions for aortic pulse pressure (Rest: 34±6mmHg; Recovery: 37±8mmHg, p=0.01), AP (Rest: 5±3mmHg; Recovery: 6±5mmHg, p=0.003), AIx normalized at 75bpm (Rest: 8.7±12.6%; Recovery: 16.4±6.0%, p=0.004), and TTI (Rest: 2084.6±273.4ms; Recovery: 2760.9±463.3ms, p=0.0001) such that they increased during recovery, compared to rest after RE, and the control. There were condition by time interactions for DPTI (Rest: 2889.6±297.0ms; Recovery: 2394.9±458.3ms, p=0.005) and subendocardial viability ratio SEVR (Rest: 138.4±19.3%; Recovery: 86.6±33.0%, p=0.006) such that they increased after acute resistance exercise, compared to rest and the control. There were no significant changes in arterial stiffness. CONCLUSION: These data suggest that resistance-trained individuals have reduced workload of the heart and lower arterial stiffness at rest, but are similar to untrained individuals after acute resistance exercise.