| dc.description.abstract | As individuals age, substantial physiological changes occur. Most notably there is a decrease in muscle mass known as sarcopenia and an increase in arterial stiffness. In order to attenuate declines in muscle mass, resistance training effectively improves both muscle size and strength of older individuals. However, the effects of resistance training on the arterial system are less clear with studies noting increased, decreased, and no change in arterial stiffness after resistance training. Purpose: The purpose of this study was to determine how aging affected arterial stiffness and other cardiovascular measure responses to a whole body resistance training session. Methods: Thirty-six men were separated into three groups based on age (Young-aged, YG: 20-39 years; middle-aged, MG: 40-59 years; older-aged, OG: 60-75 years). A randomized controlled cross-over design was used. During one condition, participants rested for 30 minutes and in the other condition, participants performed whole-body resistance exercise consisting of leg press, bench press, knee flexion, lat pulldown and knee extension (3 sets of 10 reps at 65% one-repetition maximum for each exercise). Blood pressure, augmentation pressure, augmentation index, peripheral pulse wave velocity, central pulse wave velocity, heart function, and forearm blood flow were measured before and after each condition. Change scores from pre to post time points were used for analysis. Two-way repeated measures ANOVA was used to determine differences between conditions (exercise vs. control) and groups (YG vs. MG vs. OG). Statistical significance was set at p≤0.05. Results: No differences were found between age groups for blood pressure responses. When groups were combined, peripheral systolic blood pressure significantly increased after exercise when compared to the control condition (6 ± 7 vs. 1 ± 6 mmHg, p=0.003). Also, peripheral (-5 ± 6 vs. 2 ± 4 mmHg, p<0.001) and central diastolic blood pressures (-4 ± 6 vs. 2 ± 4 mmHg, p<0.001) significantly decreased when compared to the control condition. Augmentation index significantly increased after exercise when compared to the control condition for the YG (11 ± 8 vs. 0 ± 7%, p<0.001) but not for the MG (-1 ± 8 vs. -1 ± 5%, p=0.788) or OG (-3 ± 7 vs. 2 ± 4%, p=0.076). However, no significant changes were found for central pulse wave velocity. Heart function was also not altered substantially between age groups after exercise. Conclusion: It appears that some cardiovascular variables are affected more by aging than others after performing resistance exercise. Most notably, augmentation index is significantly elevated after resistance exercise in younger individuals but not in middle-aged and older-aged individuals when compared to a control condition. However, no significant increases were noted for central pulse wave velocity for any age group. Therefore, moderate resistance training does not appear to result in acute prolonged increases in arterial stiffness in middle-aged and older-aged adults. | en_US |
