%0 Journal Article %T The Physiologic Effects of an Acute Bout of Supramaximal High-Intensity Interval Training Compared with a Continuous Exercise Bout in Patients with COPD %A Scotty J. Butcher %A Madison T. Yurach %A Nichole M. Heynen %A Brendan J. Pikaluk %A Karla J. Horvey %A Ron Clemens %A Darcy D. Marciniuk %J Journal of Respiratory Medicine %D 2013 %R 10.1155/2013/879695 %X This study compared physiological responses and work performed during a supramaximal high-intensity interval exercise training session (HIIT) and a constant work rate (CWR) exercise session. Fourteen patients with COPD (mean FEV1£¿£¿ % predicted (¡ÀSD)) completed an incremental cardiopulmonary exercise test (CPET) and a steep ramp anaerobic test (SRAT) and then two exercise bouts to symptom limitation on separate days, in random order: (1) a CWR trial at 80% of CPET peak work rate (mean £¿W) and (2) a HIIT trial using repeats of 30£¿s at 70% of SRAT peak work rate (mean £¿W) followed by 90 s at 20% of CPET peak work rate. Subjects ceased exercise primarily due to dyspnea for both HIIT and CWR (64% vs. 57%, resp.). End-exercise , HR, dyspnea, and leg fatigue were similar between the two exercise protocols. Average work rate was lower in HIIT than CWR (32 vs. 63£¿W, ); however, subjects performed HIIT longer (542 vs. 202£¿s, ) and for greater total work (23.3 vs. 12.0£¿kJ, ). The supramaximal HIIT protocol was well tolerated and demonstrated similar maximal physiologic responses to constant work rate exercise, but with greater leg muscle work performed and greater peak exercise intensity. 1. Introduction Chronic obstructive pulmonary disease (COPD) is recognized as one of the fastest growing chronic diseases leading to mortality [1]. The chief symptom of COPD is dyspnea on exertion leading to exercise intolerance and deconditioning [2]. Exercise training is a vital component of rehabilitation for patients with COPD; however, limitations on ventilation during exercise often prevent patients from attaining maximal cardiovascular and/or muscular responses. These limitations lead to significant deconditioning [3] and can impair their ability to physiologically adapt to training. High-intensity interval training (HIIT) is a method of exercise training whereby short periods of high intensity work are interspersed with periods of lower intensity recovery or rest. In many clinical populations, HIIT has achieved greater physiological adaptations than traditional exercise rehabilitation utilizing continuous constant work rate (CWR) exercise [4¨C7]. Although HIIT has been proposed as a method of addressing the reduced training effects in patients with COPD [8, 9], studies reported to date demonstrate that the physiological adaptations with HIIT are no different than those with CWR training [9¨C11], although HIIT may be better tolerated by patients than CWR training [11]. These studies, however, have typically set work rate for the high-intensity work interval using peak power %U http://www.hindawi.com/journals/jrm/2013/879695/