Exercise training in heart failure: recommendations based on current research.

A review of methods used for exercise training in stable chronic heart failure patients (CHF) shows a lack of standardization to guide prescription. Previous recommendations have been adopted from fitness training or rehabilitation studies. A model for use in CHF patients requires specific guidelines which respect the various manifestations of this illness. Pathology and exercise tolerance of patients with CHF allow only a few selected activities to be performed, such as walking and cycle ergometer training. Although the steady state method has usually been applied for aerobic exercise, the interval method has been shown to cause greater exercise stimuli to peripheral muscle than that obtained during steady state training methods without inducing greater cardiovascular stress. There is no consensus at present as to an optimal parameter for measuring intensity. An intensity of 40-80% peak oxygen consumption (VO(2)) has been applied successfully. A heart rate reserve of 60-80% or 75% of peak heart rate was used as a guide to exercise intensity without consideration of the impaired force-frequency relationship in myocardial performance. Because intensity, duration, and frequency of exercise are closely interrelated, initial exercise should be kept at 40-50% peak VO(2) with exercise duration of > 3-5 min x session performed several times daily. Progression should be followed in this order: duration, then frequency, then intensity. Resistance training can be recommended when small muscle groups are involved, using short bouts of work phases and small numbers of repetitions. To increase respiratory muscle strength and endurance, resistive inspiratory muscle training at intensity 25--35% maximum inspiratory pressure, and performed 20-30 min x d(-1), is recommended. On the basis of currently available research, supervised inpatient training programs should be preferred. Future research should be performed with respect on statistically sufficient, randomized, and controlled long-term studies that compare different training modes, intensities, frequency/duration ratios, and rates of progression.