Arterial dysfunction contributes to the development of cardiovascular disease (CVD), which is currently afflicting millions of individuals. The use of the amino acid L-citrulline has been suggested as a potential aid for the treatment of CVD by increasing endothelial production of Nitric Oxide (NO). Whole body vibration (WBV) is new and effective form of exercise that is feasible for clinical populations and has been proven to decrease blood pressure (BP) and arterial stiffness and increase muscle mass and strength. Therefore, the purpose of this study was to investigate if the combination of WBV training (WBVT) plus L-citrulline supplementation would induce positive additive effects and would be an effective means to ameliorate arterial stiffness, endothelial function, BP and muscle strength/mass in postmenopausal women.

The purpose of this study is to investigate the effects of 8 weeks combination of WBVT plus L-citrulline supplementation on arterial stiffness, endothelial function, BP and muscle strength/mass in overweight/obese postmenopausal women.

The specific aims of the study are:

1. To investigate if the additive effect of 8 weeks of WBVT combined with L-citrulline supplementation are more efficacious than either treatment alone in ameliorating cardiovascular disease risk factors by assessing arterial stiffness (aortic, systemic, and leg), aortic BP and wave reflection, and autonomic function (heart rate variability, vascular sympathetic activity [low-frequency power of systolic BP variability], and baroreflex sensitivity). Flow mediated dilation and circulating levels of adipocytokines (adiponectin and leptin) and endothelial-derived vasodilators (NO metabolites [NOx], 6-keto PGFIa, insulin, and ghrelin) and vasoconstrictors (endothelin-1 [ET-1],8-iso PGF2a,vascular endothelium growth factor [VGEF]) will be assessed as secondary outcome variables.
2. To evaluate the extent to which 8 weeks of WBVT combined with L-citrulline improves body composition assessed by changes in fat mass and lean mass using dual-energy x-ray absorptiometry and waist circumference.
3. To determine the additive effect of 8 weeks of WBVT combined with L-citrulline supplementation on muscle strength. These will be evaluated using the eight-repetition maximum test for the leg press and chest press exercises

Inclusion Criteria:

Female 50 to 70 years of age At least 1 year after menopause Body mass index of 27-39.9 Sedentary or low active (less than 2 hr per wk)

Exclusion Criteria:

Younger than 50 or older than 70 years of age Body mass index lower than 27, or 40 or higher Physically active or competitively active Smoker Use of hormone replacement therapy of less than 1 yr Use of calcium channel blocker or beta blockers Use dietary supplementations (e.g.,L-arginine,L-citrulline,antioxidants) Uncontrolled diabetes Any restriction that would significantly interfere with compliance with the L-citrulline supplementation