Resistance exercise in chronic heart failure--landmark studies and implications for practice.

In patients with chronic congestive heart failure (CHF), there is a need for complementary strength training to maintain and/or increase muscle mass and strength. The challenge is how to stress peripheral muscles intensively without creating cardiovascular overload. Since the late 1990s, an increasing number of research and clinical experiments have been conducted on resistance exercise in CHF. As a result, data are now available for both acute responses during resistance exercise as well as muscular and cardiovascular adaptation to resistance training programs, based on different training methods. Study results demonstrated that dynamic resistance exercise is well tolerated in chronic stable CHF when: 1) initial contraction intensity is low, 2) small muscle groups are involved, 3) work phases are kept short, 4) a small number of repetitions per set is performed, and 5) work/rest ratio is > or = 1:2. With tolerance, contraction intensity can be increased. With resistance training programs lasting 12 weeks, maximal strength could be improved by 15 to 50%. Improvements in maximum exercise time and peak VO2 were between 10 and 18%, in relation to baseline values. In terms of these results, no differences were reported between combined resistance/ aerobic training and resistance training alone. Thus, resistance exercise can be assumed as safe as aerobic exercise in clinically stable CHF.