title: Acute effects of continuous and interval low-intensity exercise on arterial stiffness in healthy young men.
abstract: OBJECTIVE
  To examine and compare systemic arterial stiffness responses in humans to acute continuous and interval low-intensity exercise.
  
  
  METHODS
  Fifteen healthy young men (21.2 ± 0.4 years) underwent non-exercise control (CON), continuous exercise (CE), and interval exercise trial (IE) in a randomized balanced self-control crossover design. Systemic arterial stiffness (Cardio-ankle vascular index, CAVI) was measured at baseline (BL), immediately after (0 min) and 40 min after exercise in CE and IE trials, and at corresponding time points in CON trial. Subjects cycled continuously for 30 min at 35 % heart rate reserve after BL measurement in CE trial, whereas in IE trial, subjects cycled two bouts of 15-min separated by a 20-min rest at the same intensity.
  
  
  RESULTS
  There were no significant CAVI changes with time in CON trial (6.7 ± 0.1, 6.7 ± 0.1, 6.6 ± 0.1 at BL, 0 and 40 min, respectively). In CE trial, CAVI decreased immediately after exercise (0 min) and returned to baseline after 40 min of recovery (6.5 ± 0.1, 5.5 ± 0.2, 6.4 ± 0.1 at BL, 0 and 40 min, respectively). IE elicited similar CAVI reduction from 6.7 ± 0.1 at baseline to 5.6 ± 0.2 at 0 min: however, CAVI at 40 min remained significantly low compared to that of CON trial at corresponding time point (6.0 ± 0.1 vs. 6.6 ± 0.1, P < 0.001).
  
  
  CONCLUSIONS
  Both acute continuous and interval low-intensity exercise elicits transient improvement in systemic arterial stiffness in humans. Despite equivalent exercise intensity and duration, interval exercise resulted in improved arterial stiffness for longer duration.
authors.affiliation: Cardiovascular Health Laboratory, Capital University of Physical Education and Sports, 11 Bei San Huan Xi Road, Beijing, 100191, People's Republic of China.
authors.forename: Hailin
authors.initials: H
authors.lastname: Wang
authors.forename: Taiming
authors.initials: T
authors.lastname: Zhang
authors.forename: Weili
authors.initials: W
authors.lastname: Zhu
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.forename: Shoufu
authors.initials: S
authors.lastname: Yan
mesh_terms: D001642:Bicycling; D001794:Blood Pressure; D002681:China; D018592:Cross-Over Studies; D015444:Exercise; D005080:Exercise Test; D064368:Healthy Volunteers; D006339:Heart Rate; D006801:Humans; D008297:Male; D013997:Time Factors; D059289:Vascular Stiffness; D055815:Young Adult