title: Postexercise hypotension in an endurance-trained population of men and women following high-intensity interval and steady-state cycling.
abstract: BACKGROUND
  The acute effect of high-intensity interval exercise (HI) on blood pressure (BP) is unknown although this type of exercise has similar or greater cardiovascular benefits compared to steady-state aerobic exercise (SS). This study examined postexercise hypotension (PEH) and potential mechanisms of this response in endurance-trained subjects following acute SS and HI. Sex differences were also evaluated.
  
  
  METHODS
  A total of 25 endurance-trained men (n = 15) and women (n = 10) performed a bout of HI and a bout of SS cycling in randomized order on separate days. Before exercise, 30 min postexercise, and 60 min postexercise, we measured brachial and aortic BP. Cardiac output (CO), stroke volume (SV), end diastolic volume (EDV), end systolic volume (ESV), and left ventricular wall-velocities were measured using ultrasonography with tissue Doppler capabilities. Ejection fraction and fractional shortening (FS), total peripheral resistance (TPR), and calf vascular resistance were calculated from the above variables and measures of leg blood flow.
  
  
  RESULTS
  BP, ejection fraction, and FS decreased by a similar magnitude following both bouts but changes in CO, heart rate (HR), TPR, and calf vascular resistance were greater in magnitude following HI than following SS. Men and women responded similarly to HI. Although men and women exhibited a similar PEH following SS, they showed differential changes in SV, EDV, and TPR.
  
  
  CONCLUSIONS
  HI acutely reduces BP similarly to SS. The mechanistic response to HI appears to differ from that of SS, and endurance-trained men and women may exhibit differential mechanisms for PEH following SS but not HI.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA. lindy.rossow@ou.edu
authors.forename: Lindy
authors.initials: L
authors.lastname: Rossow
authors.forename: Huimin
authors.initials: H
authors.lastname: Yan
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Fahs
authors.forename: Sushant M
authors.initials: SM
authors.lastname: Ranadive
authors.forename: Stamatis
authors.initials: S
authors.lastname: Agiovlasitis
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Wilund
authors.forename: Tracy
authors.initials: T
authors.lastname: Baynard
authors.forename: Bo
authors.initials: B
authors.lastname: Fernhall
mesh_terms: D000328:Adult; D001642:Bicycling; D001783:Blood Flow Velocity; D002302:Cardiac Output; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005081:Exercise Therapy; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D006973:Hypertension / Q000628:therapy; D007022:Hypotension / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D012737:Sex Factors; D014463:Ultrasonography; D014655:Vascular Resistance; D055815:Young Adult