Chronic heart failure (CHF) patients have poor exercise tolerance, which does not correlate with impaired central function. Consequently factors other than impaired cardiac function must contribute to the exercise intolerance. Maladaptations in skeletal muscle appear to be a likely reason for the limited exercise tolerance. In study I, exercise tolerance and skeletal muscle metabolism and morphology were examined in 17 CHF patients and eight healthy similarly aged sedentary control subjects. In Study II, thirteen CHF patients participated in a study on the effects of resistance training on exercise tolerance and skeletal muscle morphology and metabolism.