title: Effects of Stretching Exercise on Heart Rate Variability During Pregnancy.
abstract: BACKGROUND
  Little evidence exists for effects of low-intensity exercises such as stretching on cardiovascular health in pregnant women.
  
  
  OBJECTIVE
  Our aim was to evaluate the effect of a 20-minute stretching exercise on heart rate variability (HRV), blood pressure (BP), and heart rate (HR) in healthy pregnant women.
  
  
  METHODS
  In 15 pregnant women with a mean (SD) age of 29.47 (4.07) years and mean (SD) gestational weeks of 26.53 (8.35), HRV, and BP were measured before and after the 20-minute stretching exercise.
  
  
  RESULTS
  Compared with before the stretching exercise, standard deviation of the normal-to-normal intervals, total variability of heart rate, increased by 7.40 milliseconds (t = -2.31, P = .04) and root mean square of successive differences, a surrogate measure of parasympathetic outflow, also increased by 11.68 milliseconds (Z = -2.04, P = .04) after the stretching exercise. Diastolic BP and HR decreased by 2.13 mm Hg (t = 1.93, P = .07) and 3.31 bpm (t = 2.17, P = .05), respectively, but they did not reach statistical significance.
  
  
  CONCLUSIONS
  These preliminary data suggest that 20 minutes of stretching exercise may promote cardiovascular health by attenuating the loss of parasympathetic tone associated with pregnancy.
authors.affiliation: Jeongok G. Logan, PhD, MSN, RN Assistant Professor, School of Nursing, University of Virginia, Charlottesville. SeonAe Yeo, PhD, RNC, FAAN Professor, School of Nursing, University of North Carolina at Chapel Hill.
authors.forename: Jeongok G
authors.initials: JG
authors.lastname: Logan
authors.forename: SeonAe
authors.initials: S
authors.lastname: Yeo
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D052580:Muscle Stretching Exercises; D010865:Pilot Projects; D011247:Pregnancy / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult