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New Findings: What is the central question of this study? The aim was to establish the ability of a newly designed leg exercise technique to produce sustained elevations in shear rate that stimulate flow-mediated dilatation (FMD) in the superficial femoral artery and to determine the repeat trial stability of the FMD response. What is the main finding and its importance? Calf plantar-flexion exercise can be used to increase shear stress and stimulate FMD in the superficial femoral artery. However, the magnitude of FMD varied systematically when multiple trials were repeated in short succession. The superficial femoral artery (SFA) is susceptible to vascular disease, and a technique to assess flow-mediated dilatation (FMD) in this vessel in response to a sustained shear stress stimulus could provide important information about endothelial function. The aim of this study was to establish the ability of a newly designed SFA leg exercise-FMD (LEX-FMD) technique to produce sustained elevations in shear rate, which stimulate FMD, and to determine the repeat trial stability of the FMD response. The SFA FMD stimulated by reactive hyperaemia (RH) and calf plantar-flexion exercise (LEX) was assessed via ultrasound in 19 healthy men (n = 10) and women (n = 9). The two experimental visits included either four trials of LEX-FMD or four trials of RH-FMD. The shear stress stimulus was estimated as the shear rate (blood velocity/SFA diameter). Results are expressed as the means ± SD. The LEX steady-state shear rate was consistent between trials (P = 0.176), whereas the RH shear rate area under the curve was higher in trial 1 versus trials 2-4 (P < 0.05). The %RH-FMD (four-trial mean 4.9 ± 2.5%) and absolute RH-FMD were not significantly different between trials (P = 0.465 and P = 0.359, respectively). Both %LEX-FMD and absolute LEX-FMD were higher during trial 3 (4.8 ± 3.4%) than trial 1 (3.6 ± 2.7%; P = 0.026 and P = 0.026, respectively). The magnitude of RH-FMD and LEX-FMD did not differ (P = 0.241). These results indicate that calf plantar-flexion exercise can be used to increase shear stress and stimulate FMD in the SFA. However, although SFA RH-FMD was stable across four trials, LEX-FMD varied systematically when multiple trials were repeated in rapid succession., (© 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.)

The effect of resistance training on arterial stiffening is controversial. We tested the hypothesis that resistance training would not alter central arterial compliance. Young healthy men (age, 23 ± 3.9 (mean ± s.e.m.) years; n= 28,) were whole-body resistance trained five times a week for 12 weeks, using a rotating 3-day split-body routine. Resting brachial blood pressure (BP), carotid pulse pressure, carotid cross-sectional compliance (CSC), carotid initima–media thickness (IMT) and left ventricular dimensions were evaluated before beginning exercise (PRE), after 6 weeks of exercise (MID) and at the end of 12 weeks of exercise (POST). CSC was measured using the pressure-sonography method. Results indicate reductions in brachial (61.1 ± 1.4 versus 57.6 ± 1.2 mmHg; P < 0.01) and carotid pulse pressure (52.2 ± 1.9 versus 46.8 ± 2.0 mmHg; P < 0.01) PRE to POST. In contrast, carotid CSC, β-stiffness index, IMT and cardiac dimensions were unchanged. In young men, central arterial compliance is unaltered with 12 weeks of resistance training and the mechanisms responsible for cardiac hypertrophy and reduced arterial compliance are either not inherent to all resistance-training programmes or may require a prolonged stimulus. [ABSTRACT FROM AUTHOR]