Differential effects of high-frequency versus low-frequency exercise training in rehabilitation of patients with coronary artery disease

OBJECTIVES We sought to study the influence of frequency of exercise traini ng during cardiac rehabilitation on functional capacity (i.e., peak oxygen consumption [VO2] and ventilatory anaerobic threshold [VAT]) and quality of life (QoL). BACKGROUND Although the value of cardiac rehabilitation is now well establi shed, the influence of the different program characteristics on outcome has received little attention, and the effect of frequency of exercise trainin g is unclear. Functional capacity is regularly evaluated by peak VO2 but pa rameters of submaximal exercise capacity such as VAT should also be conside red because submaximal exercise capacity is especially important in daily l iving. METHODS Patients with coronary artery disease (n = 130, 114 men; mean age 5 2 +/- 9 years) were randomized to either a high- or low-frequency program o f six weeks (10 or 2 exercise sessions per week of 2 h, respectively). Func tional capacity and QoL were assessed before and after cardiac rehabilitati on. Global costs were also compared. RESULTS Compared with baseline, mean exercise capacity increased in both pr ograms: for high- and low-frequency, respectively: peak VO2 = 15% and 12%, Wmax = 18% and 12%, VAT = 35% and 12% (all p < 0.001). However, when the pr ograms were compared, only VAT increased significantly more during the high -frequency program (p = 0.002). During the high-frequency program, QoL incr eased slightly more, and more individuals improved in subjective physical f unctioning (p = 0.014). We observed superiority of the high-frequency progr am, especially in younger patients. Mean costs were estimated at 4,455 and 2,273 Euro, respectively, for the high- and low-frequency programs. CONCLUSIONS High-frequency exercise training is more effective in terms of VAT and QoL, but peak VO2 improves equally in both programs. Younger patien ts seem to benefit more from the high-frequency training. (C) 2000 by the A merican College of Cardiology.