title: Intensity-dependent reductions in resting blood pressure following short-term isometric exercise training.
abstract: To reduce resting blood pressure, a minimum isometric exercise training (IET) intensity has been suggested, but this is not known for short-term IET programmes. We therefore compared the effects of moderate- and low-intensity IET programmes on resting blood pressure. Forty normotensive participants (22.3 ± 3.4 years; 69.5 ± 15.5 kg; 170.2 ± 8.7 cm) were randomly assigned to groups of differing training intensities [20%EMGpeak (~23%MVC, maximum voluntary contraction, or 30%EMGpeak (~34%MVC)] or control group; 3 weeks of IET at 30%EMGpeak resulted in significant reductions in resting mean arterial pressure (e.g. -3.9 ± 1.0 mmHg, P < 0.001), whereas 20%EMGpeak did not (-2.3 ± 2.9 mmHg; P > 0.05). Moreover, after pooling all female versus male participants, IET induced a 6.9-mmHg reduction in systolic blood pressure in female participants, but only a 1.5-mmHg reduction in systolic blood pressure in male participants, although the difference was not significant. An IET intensity between 20%EMGpeak and 30%EMGpeak is sufficient to elicit significant resting blood pressure reductions in a short-term training period (3 weeks). In addition, sexual dimorphism may exist in the magnitude of reductions, but further work is required to confirm this possibility, which could be important in understanding the mechanisms responsible.
authors.affiliation: a Laboratory of Systems Physiology, Department of Kinesiology , University of North Carolina at Charlotte , Charlotte , NC , USA.
authors.forename: Kyle F
authors.initials: KF
authors.lastname: Gill
authors.forename: Susan T
authors.initials: ST
authors.lastname: Arthur
authors.forename: Ian
authors.initials: I
authors.lastname: Swaine
authors.forename: Gavin Richard
authors.initials: GR
authors.lastname: Devereux
authors.forename: Yvette M
authors.initials: YM
authors.lastname: Huet
authors.forename: Erik
authors.initials: E
authors.lastname: Wikstrom
authors.forename: Mitchell L
authors.initials: ML
authors.lastname: Cordova
authors.forename: Reuben
authors.initials: R
authors.lastname: Howden
mesh_terms: D000328:Adult; D001794:Blood Pressure; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D010806:Physical Education and Training / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
keywords: isometric exercise intensity; isometric exercise training; resting blood pressure