title: The effect of high intensity interval training on cardioprotection against ischemia-reperfusion injury in wistar rats.
abstract: The aims of the present study were to determine whether short term high intensity interval training (HIIT) could protect the heart against ischemia reperfusion (IR) injury; and if so, to evaluate how long the exercise-associated protection can be lasted. Sixty-three rats were randomly assigned into sedentary (n = 15), sham (n = 7), and exercise groups (n = 41). Rats in the exercise groups performed 5 consecutive days of HIIT on treadmill: 5 min warm up with 50 % VO2max, 6×2 min with 95-105 % VO2max (about 40 to 45 m/min), 5×2 min recovery with 65-75 % VO2max (about 28 to 32 m/min), and 3 min cool down with 50 % VO2max, all at 0 % grade. Animals exposed to an in vivo cardiac IR surgery, performed at days 1, 7, and 14 following the final exercise session. Ischemia-induced arrhythmias, myocardial infarct size (IS), plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities were measured in all animals. Compared to sedentary rats, exercised animals sustained less IR injury as evidenced by a lower size of infarction and lower levels of LDH and CK at day one and day 7 post exercise. In comparison of sedentary group, IS significantly decreased in EX-IR1 and EX-IR7 groups (50 and 35 %, respectively), but not in EX-IR14 group (19 %). The exercise-induced cardioprotection disappeared 14 days following exercise cessation. There were no significant changes in ischemia-induced arrhythmia between exercised and sedentary rats. The results clearly demonstrate that HIIT protects the heart against myocardial IR injury. This protective effect can be sustained for at least one week following the cessation of the training.
authors.affiliation: Exercise Physiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Rahimi
authors.affiliation: Department of Physiology, Arsanjan Branch, Islamic Azad University, Fars, Iran.
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Shekarforoush
authors.affiliation: Faculty of Aerospace Medicine, AJA University of Medicine Sciences, Tehran, Iran.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Asgari
authors.affiliation: Exercise Physiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Khoshbaten
authors.affiliation: Faculty of Physical Education and Exercise Sciences, Kharazmi University, Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Rajabi
authors.affiliation: Exercise Physiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Behzad
authors.initials: B
authors.lastname: Bazgir
authors.affiliation: Department of Physiology and Biophysics, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Taghi
authors.initials: MT
authors.lastname: Mohammadi
authors.affiliation: Exercise Physiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Sobhani
authors.affiliation: Exercise Physiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Shakibaee
keywords: cardioprotection; exercise training; ischemia; reperfusion