Aerobic Plus Resistance Training May Improve Coronary Artery Disease Outcomes
Aerobic Plus Resistance Training May Improve Coronary Artery Disease Outcomes CME/CE
News Author: Laurie Barclay, MD
CME Author: Désirée Lie, MD, MSEd
August 27, 2008 — In patients with coronary artery disease, aerobic training (AT) combined with resistance training (RT) improves many outcomes, according to the results of a randomized study reported in the September issue of Medicine & Science in Sports & Exercise.
“Combined…AT and…RT rehabilitation programs are rapidly becoming standard treatments for individuals with coronary artery disease,” write Susan Marzolini, from the University of Toronto in Ontario, Canada, and colleagues. “Although recommendations for the AT prescription are widely known, the RT prescription when combined with AT remains unclear. Recently established RT practice guidelines for patients with CAD [coronary artery disease] advocate the use of one set of six to ten exercises.”
The objective of the study was to compare the effects of 1 set or 3 sets of RT combined with AT vs AT alone in 72 persons with coronary artery disease. Participants were randomly assigned to AT (5 days/week) or combined AT (3 days/week) with either 1 set (AT/RT1) or 3 sets (AT/RT3) of RT performed 2 days/week. Before and after 29 weeks of training, VO2 peak, ventilatory anaerobic threshold (VAT), strength and endurance, body composition, and adherence were assessed.
Training was completed by 53 participants (mean age, 61 ± 2 years). The difference between groups was not significant for the average increase from baseline in VO2 peak (L/minute), which was 11% for AT (P < .05), 14% for AT/RT1 (P < .01), and 18% for AT/RT3 (P < .001). VAT improved significantly from baseline only in the AT/RT3 group (P < .05). Compared with the AT group, the AT/RT3 group had greater gain in lean mass (1.5 vs 0.4 kg; P < .01). However, gains between AT/RT1 and AT were similar (P = .20).
Reduction in body fat occurred only in the combined AT/RT groups (P < .05). Compared with the AT-alone group, strength and endurance increased more in the AT/RT groups (P < .05). The AT/RT3 group had lower adherence to the number of sets performed vs the AT/RT1 group (P < .02).
“Combined AT + RT yields more pronounced physiological adaptations than AT alone and appears to be superior in producing improvements in VO2 peak, muscular strength and endurance, and body composition,” the study authors write. “The data support the use of multiple set RT for patients desiring an increased RT stimulus which may further augment parameters that affect VO2 peak, VAT, lower body endurance, and muscle mass in a cardiac population.”
Limitations of this study include inability to fully explain how randomization resulted in the AT/RT1 group having a significantly greater VAT, leg strength, and leg lean mass at baseline than the AT/RT3 group and the imbalance in diagnoses between groups; lack of a physically inactive control group; and graded exercise tests conducted on a cycle ergometer, whereas the aerobic exercise prescription included walking, limiting relevance to activities of daily living.
“The combination of RT and AT yields greater improvements in cardiovascular endpoints of exercise performance, skeletal muscle function, and body composition compared to AT alone, in spite of a 28% reduction in the actual AT training stimulus,” the study authors conclude. “These data strongly support a combined training intervention in CAD patients, and supports the use of multiple-set RT for patients desiring an increased RT stimulus.”
The Toronto Rehabilitation Institute and Ministry of Health funded this research. The study authors have disclosed no relevant financial relationships.
Med Sci Sports Exerc. 2008;40:1557-1564.
Clinical Context
Combined AT and RT is becoming a standard of care for rehabilitation in patients with coronary artery disease and is believed to provide better gains in strength, body composition, and exercise performance as measured by VO2 peak and VAT than AT alone.
This is a study comparing AT with 1 (RT1) and 3 (RT3) sets of RT in patients with coronary artery disease to examine effects on exercise and cardiovascular fitness, muscle mass and strength, body fat, and adherence to the programs.
