title: Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives.
abstract: BACKGROUND
  During nocturnal sleep, blood pressure (BP) "dips" compared to diurnal BP, reducing stress on the cardiovascular system. Both the hypotensive response elicited by acute aerobic exercise and sleep quality can impact this dipping response.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the effects of aerobic exercise timing on circadian BP changes and sleep architecture.
  
  
  METHODS
  Twenty prehypertensive subjects completed the study. During four test sessions, participants first completed a graded exercise test to exhaustion and then performed 30 minutes of treadmill exercise at 7 am (7A), 1 pm (1P), and 7 pm (7P) in a random, counterbalanced order at 65% of the heart rate obtained at peak oxygen uptake. An ambulatory cuff was used to monitor BP responses during 24 hours following exercise, and an ambulatory sleep-monitoring headband was worn during sleep following each session.
  
  
  RESULTS
  Aerobic exercise at 7A invoked a greater dip in nocturnal systolic BP than exercise at 1P or 7P, although the greatest dip in nocturnal diastolic BP occurred following 7P. Compared to 1P, 7A also invoked greater time spent in deep sleep.
  
  
  CONCLUSIONS
  These data indicate that early morning may be the most beneficial time to engage in aerobic exercise to enhance nocturnal BP changes and quality of sleep.
authors.affiliation: Vascular Biology and Autonomic Studies Laboratory, Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Fairbrother
authors.affiliation: Vascular Biology and Autonomic Studies Laboratory, Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Cartner
authors.affiliation: Vascular Biology and Autonomic Studies Laboratory, Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Alley
authors.affiliation: Vascular Biology and Autonomic Studies Laboratory, Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
authors.forename: Chelsea D
authors.initials: CD
authors.lastname: Curry
authors.affiliation: Department of Economics, Appalachian State University, Boone, NC, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Dickinson
authors.affiliation: Vascular Biology and Autonomic Studies Laboratory, Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Morris
authors.affiliation: Vascular Biology and Autonomic Studies Laboratory, Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Collier
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058246:Prehypertension / Q000503:physiopathology* / Q000517:prevention & control; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
keywords: aerobic exercise; nocturnal dipping; prehypertension