A comparison of high versus low dose of exercise training in exercise-based cardiac rehabilitation: a randomized controlled trial with 12-months follow-up

• Published in: Clinical rehabilitation Vol. 34; no. 1; p. 69
• Main Authors: Petersen, Annemette Krintel, Oestergaard, Lisa Gregersen, van Tulder, Maurits, Laustsen, Sussie
• Format: Journal Article
• Language: English
• Published: England 01.01.2020
• Subjects: Cardiac Rehabilitation - methods; Denmark; Exercise Therapy - methods; Exercise Tolerance; Female; Follow-Up Studies; Humans; Male; Middle Aged; Muscle Strength - physiology; Quality of Life; Resistance Training; Denmark; physical capacity; dose response; Cardiac rehabilitation; exercise training; randomized controlled trial
• ISSN: 1477-0873
• DOI: 10.1177/0269215519883411

To assess if a higher dose of exercise training in exercise-based cardiac rehabilitation could affect improvements in aerobic capacity and muscle strength. Assessor-blinded randomized controlled trial with 12-months follow-up. Aarhus University Hospital, Aarhus, Denmark. A total of 164 cardiac patients referred to exercise-based cardiac rehabilitation were recruited. Patients were randomized to 1-hour exercise sessions either three times weekly for 12 weeks (36 sessions, high-dose group) or twice weekly for 8 weeks (16 sessions, low-dose group). The same standardized exercise and intensity protocol including aerobic and muscle strength training was used in all participants. Primary outcome was changes in VO . Secondary outcomes were changes in maximal workload, muscle strength and power. Measures were obtained at baseline, after termination of the rehabilitation programme and at follow-up after 6 and 12 months. After the end of intervention, statistically significant between-group differences were seen in favour of the high-dose group in all outcomes: VO 2.6 (mL kg  min ) (95% confidence interval (CI): 0.4-4.8), maximal workload 0.3 W kg (95%CI: 0.02-0.5), isometric muscle strength 0.7 N m kg (95%CI: 0.1-1.2) and muscle power 0.3 W kg (95%CI: 0.04-0.6). After 12 months, a significant between-group difference only persisted in VO and maximal workload. A higher dose of exercise training had a small effect on all outcomes at termination of intervention. A long-term effect persisted in VO and maximal workload. Although the effect was small, it is an important finding because VO is the most important predictor of all-cause mortality in cardiac patients.