title: Cardioprotective Effect of High Intensity Interval Training and Nitric Oxide Metabolites (NO2 (-), NO3 (-)).
abstract: BACKGROUND
  The aim of this study was to investigate the effects of High-Intensity Interval Training (HIIT) on nitric oxide metabolites (NO2(-), NO3(-)) and myocardial infarct size after Ischemia/Reperfusion (I/R) injury in healthy male rats.
  
  
  METHODS
  A total of 44 Wistar rats were randomly divided into 4 groups including HIIT (n=8), HIIT + IR protocol (n=14), control (n=8), and control + IR (n=14). Each training session of HIIT consisted of 1 hour of exercise in three stages: 6-minute running at 50-60% VO2max for warm-up; 7 intervals of 7-minute running on treadmill with a slope of 5° to 20° (4 minutes with an intensity of 80-100% VO2max and 3 minutes at 50-60% VO2max); and 5-minute running at 50-60% VO2max for cool-down. The control group did not participate in any exercise program. Nitric Oxide (NO) and its metabolites were measured by using Griess reaction test.
  
  
  RESULTS
  The results showed that eight weeks of exercise training exerted a significantly increasing effect on nitrite (8.55 μmol per liter, equivalent to 34.79%), nitrate (62.02 μmol per liter, equivalent to 149.48%), and NOx (66 μmol per liter, equivalent to 98.11%) in the HIIT group compared with the control group. The results showed myocardial infract size (IS) was significantly smaller (23.2%, P<0.001) in the exercise training group compared with the control group.
  
  
  CONCLUSIONS
  Incremental changes in NO-NO3 (-), NO2 (-) axis are one of mechanisms through which HIIT program can protect the heart from I/R injury and decrease myocardial infarction.
authors.affiliation: Dept. of Physical Education and Sport Science, School of Education and Psychology, Shiraz University, Shiraz, Iran ; Sport Physiology Research Center, Baghiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Aliasghar
authors.initials: A
authors.lastname: Fallahi
authors.affiliation: Dept. Exercise Physiology, Faculty of Physical Education and Sport Science, Tehran University, Tehran, Iran.
authors.forename: Abbasali
authors.initials: A
authors.lastname: Gaeini
authors.affiliation: Dept. of Physiology, Arsanjan Branch, Islamic Azad University, Fars, Iran.
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Shekarfroush
authors.affiliation: Sport Physiology Research Center, Baghiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Khoshbaten
keywords: Cardioprotection; High-intensity interval training; NO; NO2−; NO3−; Preconditioning