title: Can relaxation lower metaboreflex-mediated blood pressure elevations?
abstract: OBJECTIVE
  Relaxation can lower resting blood pressure, and this investigation sought to determine whether relaxation could reduce mean blood pressure (MBP) elevations produced by postexercise circulatory occlusion (PECO).
  
  
  METHODS
  Sixteen volunteers trained with relaxation and were able to decrease MBP at rest by at least 5 mm Hg within 2 min. Subjects performed four tests assigned randomly: i). rest with cuff occlusion, ii). rest and cuff occlusion with relaxation, iii). hand-grip exercise followed by PECO rest with cuff occlusion, and iv) hand-grip exercise followed by PECO with relaxation. Data for HR and MBP were collected using a Finapres; ratings of relaxation and discomfort from cuff occlusion were obtained using a 1- to 10-unit scale. Stroke volume (SV) and HR were collected from six subjects to calculate cardiac output and total peripheral conductance (TPC). Dependent variables were compared using an ANOVA.
  
  
  RESULTS
  HR (mean +/-SD) was lower during both relaxation conditions as compared with control (-7 +/- 4 bpm vs -2 +/- 3 bpm; P< 0.05). The MBP was reduced during relaxation alone (-6 +/- 3.7 mm Hg; < 0.05) but not during PECO with relaxation. The rating of relaxation was higher during relaxation (6.8 +/- 1.3 units) versus control (3.5 +/- 1.2 units), but ratings were not different between relaxation conditions. Ratings of discomfort were higher during PECO ( P< 0.05). Relaxation did not significantly alter CO or SV (N= 6). During relaxation alone, TPC was increased (0.046 +/- 0.001 vs 0.049 +/- 0.002 L.min.mm Hg; P< 0.05). However, TPC was significantly increased during PECO with relaxation.
  
  
  CONCLUSIONS
  These findings suggest that although relaxation can affect cardiovascular regulation and lower HR and MBP at rest, this central signal cannot lower reflex increases in blood pressure originating from a peripheral metabolic stimulus.
authors.affiliation: Department of Physical Therapy, University of Texas Southwestern Medical Center, Dallas, TX 75235-8876, USA.
authors.forename: Brandi
authors.initials: B
authors.lastname: Anthony
authors.forename: Lisa
authors.initials: L
authors.lastname: Boudreaux
authors.forename: Iris
authors.initials: I
authors.lastname: Dobbs
authors.forename: Samsha
authors.initials: S
authors.lastname: Jamal
authors.forename: Patricia
authors.initials: P
authors.lastname: Guerra
authors.forename: Jon W
authors.initials: JW
authors.lastname: Williamson
mesh_terms: D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D001775:Blood Circulation / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology*; D012146:Rest / Q000502:physiology