Objective Effects of a 6 Months' Endurance and Strength Training Program in Outpatients With Congestive Heart Failure.

Objective Effects of a 6 Months' Endurance and Strength Training Program in Outpatients With Congestive Heart Failure Delagardelle C, Feiereisen R, Krecke R, et al (Service de Cardiologie, Centre Hospitalier de Luxembourg, Luxembourg, Grand Duchy of Luxembourg), Med Sci Sports Exerc. 1999;31:1102-1107.

Congestive heart failure has been shown to cause deconditioning due to inactivity as well as causing selective type-II muscle fiber atrophy. Aerobic exercise programs have become part of the recommended treatment of this disease, and strength-training programs are beginning to show promise. Therefore, the purpose of this study was to test the feasibility and effects of a carefully planned and supervised strength and endurance program for persons with congestive heart failure.

Fourteen subjects (11 men, 3 women) participated in the study. These subjects had a mean age of 57 years, a mean New York Heart Association classification of 2.7, a mean left ventricular ejection fraction of 29%, and a mean peak oxygen consumption of 17.2 ml/kg/min. Prior to training, all subjects underwent ultrasound and scintiographic studies of cardiac function, a symptom-limited bicycle ergometer test that included lactate levels, and isokinetic tests of knee flexion and extension strength and endurance.

Training consisted of 3 hour-long sessions per week for 6 months directed by physical therapists and a cardiologist at a hospital-based cardiac rehabilitation program. The initial 3 weeks were used to familiarize the subjects with the program. This introductory period was followed by four 6-week cycles that increased in intensity. Endurance training consisted of treadmill walking and cycling, initially at 60% of peak oxygen consumption and progressing to 75% and incorporating interval training in 2-minute bouts, which alternated between 50% and 75% of peak oxygen consumption.

Strengthening exercises consisted of the use of pulleys, dumbbells, stair climbing, and medicine-ball exercises for leg extensors and flexors, shoulder muscles, and abdominal muscles. Three sets of 15 repetitions--initially at 60% of the subject's 10-repetition maximum and then progressing to 80% of this level--were performed. Each training session concluded with 10 minutes of stretching.

Adherence to the exercise program was 89%. No major orthopedic or cardiovascular complications occurred during training. However, two subjects had to be hospitalized during the study: one for rapid atrial fibrillation and one for anemia. Both subjects were able to resume training following a short hospital stay.

Following the training period, the authors found significant improvements in New York Heart Association classification and working capacity. There was no significant change in cardiac function, although peak oxygen consumption, vital capacity, forced expiratory volume in 1 second, and level of ventilatory threshold all increased. Strength improvements were seen in knee extensors, but not flexors. The endurance of both muscle groups was significantly increased: 18% for knee flexors and 25% for knee flexors. A significant decrease in resting heart rate was also observed.

According to the researchers, this study demonstrated the safety and efficacy of a 6-month, supervised training program for persons with congestive heart failure. The authors recommended further studies with larger populations and the use of a control group.

Anne K Swisher, PT
West Virginia University
Morgantown, WVa