Author + information
- Received January 25, 1995
- Revision received May 9, 1995
- Accepted May 15, 1995
- Published online October 1, 1995.
- Romualdo Belardinelli, MDa,
- Demetrios Georgiou, MDa,*,*,
- Vito Scocco, MDa,
- Thomas J. Barstow, PhDa,* and
- Augusto Purcaro, MDa
- ↵*Address for correspondence: Dr. Demetrios Georgiou, South Valley Cardiovascular Group, 18550 Saint Louise Drive. Suite 201, Morgan Hill, California 95037.
Objectives. The present study was designed to evaluate whether a specific program of low intensity exercise training may be sufficient to improve the exercise tolerance of patients with chronic heart failure.
Background. Recent studies have shown that exercise training can improve exercise tolerance in patients with stable chronic heart failure, mainly through peripheral adaptations. These changes have been observed with exercise regimens at intensities of 70% to 80% of peak oxygen uptake and >8 weeks.
Methods. We studied 27 patients (23 men, 4 women; mean [±SD] age 57 ± 6 years) with mild chronic heart failure. We classified patients into two groups: trained group and untrained group. The trained group underwent a low intensity (40% of peak oxygen uptake) training program three times/week for 8 weeks. The untrained group performed no exercise.
Results. An increase in peak oxygen uptake (17%, p < 0.0001), lactic acidosis threshold (20%, p < 0.0002) and peak work load (21%, p < 0.0002) were obtained in the trained group only. Cardiac output and stroke volume were unchanged. A high correlation was found between the increases in peak oxygen uptake and volume density of mitochondria of vastus lateralis muscle (r = 0.77, p < 0.0002).
Conclusions. Patients with stable chronic heart failure can achieve significant improvement in functional capacity from a low intensity exercise training regimen. The mechanism responsible for this favorable effect involves an increase in mitochondrial density, which reflects an improvement in oxidative capacity of trained skeletal muscles.
This study was presented in part at the 66th Annual Scientific Sessions of the American Heart Association, Atlanta, Georgia, November 1993. It was supported by a grant from Unita Sanitacia Locale 12, Ancona, Italy.
- Received January 25, 1995.
- Revision received May 9, 1995.
- Accepted May 15, 1995.
- American College of Cardiology