title: The efficacy of isometric resistance training utilizing handgrip exercise for blood pressure management: A randomized trial.
abstract: BACKGROUND
  Hypertension is a major risk factor contributing to cardiovascular disease, which is the number one cause of deaths worldwide. Although antihypertensive medications are effective at controlling blood pressure, current first-line treatment for hypertension is nonpharmacological lifestyle modifications. Recent studies indicate that isometric resistance training (IRT) may also be effective for assisting with blood pressure management. The aim of this study was to determine the efficacy of IRT for blood pressure management and the suitability of a low-intensity working control group.
  
  
  METHODS
  Forty hypertensive individuals, aged between 36 and 65 years, conducted IRT for 8 weeks. Participants were randomized into 2 groups, working at an intensity of either 5% or 30% of their maximum voluntary contraction. Participants performed 4 × 2 minute isometric handgrip exercises with their nondominant hand, each separated by a 3-minute rest period, 3 days a week.
  
  
  RESULTS
  Blood pressure measurements were conducted at baseline and at the end of the protocol using a Finometer. Eight weeks of isometric resistance training resulted in a 7-mmHg reduction of resting systolic blood pressure (SBP) (136 ± 12 to 129 ± 15; P = 0.04) in the 30% group. Reductions of 4 mmHg were also seen in mean arterial pressure (MAP) (100 ± 8 to 96 ± 11; P = 0.04) in the 30% group. There were no statistically significant reductions in diastolic blood pressure for the 30% group, or any of the data for the 5% group.
  
  
  CONCLUSIONS
  Isometric resistance training conducted using handgrip exercise at 30% of maximum voluntary contraction significantly reduced SBP and MAP. A lack of reduction in blood pressure in the 5% group indicates that a low-intensity group may be suitable as a working control for future studies.
authors.affiliation: School of Science and Technology, University of New England, Armidale, New South Wales, Australia.
authors.forename: Debra J
authors.initials: DJ
authors.lastname: Carlson
authors.forename: Jodie
authors.initials: J
authors.lastname: Inder
authors.forename: Suresh K A
authors.initials: SKA
authors.lastname: Palanisamy
authors.forename: James R
authors.initials: JR
authors.lastname: McFarlane
authors.forename: Gudrun
authors.initials: G
authors.lastname: Dieberg
authors.forename: Neil A
authors.initials: NA
authors.lastname: Smart
mesh_terms: D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006225:Hand; D018737:Hand Strength; D006801:Humans; D006973:Hypertension / Q000628:therapy*; D007537:Isometric Contraction; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D013599:Systole