Sex Difference On Arterial Stiffness And Measures Of Pulse Wave Reflection Response To Weight Machines

Abstract

PURPOSE: To evaluate sex-specific responses to acute bout of machine weight resistance exercise on arterial stiffness and measures of pulse wave reflection. METHODS: Resistance-trained men (n=21; Mean±SD: Age: 23±3yrs) and women (n=20: Age: 22±3yrs) volunteered to participate in the study. Arterial stiffness, measured via pulse wave velocity, and measures of pulse wave reflection, were evaluated at rest, and 10 minutes following an acute bout of weight machine exercise composed of 3 sets of 10 reps at 75% 1RM on the chest press, leg press, lat pulldown, leg flexion and leg extension. Two minutes of rest was given between sets and exercises. A 2x2x2 ANOVA was used to analyze the effects of sex (men, women) across condition (acute resistance exercise, control) and time (rest, recovery (Rec)). RESULTS: There were no significant three-way interactions for any variable, as well as no sex specific responses. Acute resistance exercise had no effect on arterial stiffness (p=0.07), or augmentation pressure (p=0.16). A significant condition by time interaction (p=0.001) was noted for [email protected] ([email protected]: Men: Rest: 7.0±8.1%; Rec: 19.4±9.2%; Women: Rest: 11.0±16.0%; Rec: 14.0±6.0%) such that it was increased in response to the acute resistance exercise, but not the control. A significant (p=0.0001) condition by time effect was also noted for the subendocardial viability ratio (SEVR: Men: Rest: 141.0±24.0%; Rec: 82.1±38.0%; Women: Rest: 136.0±13.4%; Rec: 91.3±28.0%) in that the acute resistance exercise reduced SEVR during recovery, but not the control. There was also a significant (p=0.007) main effect of time for myocardial workload (Ew: Men: Rest: 809.0±639.2dynes s/cm2; Rec: 984.0±896.0dynes s/cm2; Women: Rest: 985.0±965.0dynes s/cm2; Rec: 364.0±540.0dynes s/cm2) in that it was reduced during recovery from the acute resistance exercise compared to rest, as well as the control. CONCLUSIONS: These data suggest that weight machines may not significantly alter arterial stiffness or measures of pulse wave reflection differently between the sexes. However, an acute bout of resistance exercises consisting of weight machines may reduce function of the left ventricle for at least 10 minutes.