Assessment of Two Training Modalities Effects on Exercise Tolerance after a Cardiac Rehabilitation Program and 3 Months Later in Off-Pump Coronary Artery Bypass Patients

Abstract

Background. Physical training is recommended as an efficient therapy in patients with coronary disease. However its effects should depend on its modalities. The aim of this study was to compare the effects of continuous and interval training after off-pump coronary artery bypass surgery (CABG).
 
 Methods. Twenty-three male patients (59.5 ± 1.2 yr) underwent a randomized physical training using continuous (C, n=10) or interval (IT, n=13) modalities, over 3 weeks (5 h. a week). All patients performed a symptom-limited exercise test with measurements of ventilatory threshold (VT) and peak workload (WL), oxygen uptake (VO2) and heart rate (HR), before, at the end and 3 months after the training period. They also completed the SF-36 questionnaire to assess their quality of life.
 
 Results. Both C and IT improved WL and VO2 at VT (P < 0.05) and at peak exercise (P < 0.05). Only IT increased peak HR and HR reserve (P < 0.01). In both groups quality of life was improved (P < 0.05). In both groups, compared to after training, the 3-months assessment showed an increase in peak and ventilatory threshold WL, and in peak HR (P < 0.05) without any change in peak VO2 and VT HR. No difference was observed between groups whatever the period studied. Back to home, in accordance with the given recommendations, most of the patients carried on their physical training over 3 months. They performed either outside walking (n=9) or cycling sessions (n=1) or both activities (n=11). No difference concerning the global training schedule was noted regardless their group (5.4 ± 1.2 vs. 6.0 ± 1.1 h.week-1 for C and IT, respectively).
 
 Conclusions. In off-pump CABG patients, similar improvements of exercise capacity and quality of life perception were observed after both C and IT programs. Only peak HR was increased after interval training. Thus, IT is a good alternative to C training in this population. Aerobic fitness still remained stable or increased after 3 months of individual practice which duration exceeded the minimal values recommended.