Randomized controlled trial of home-based exercise training to evaluate cardiac functional gains

There is evidence that multiple benefits can be obtained through exercise training that leads to increases in peak oxygen consumption (_O2). It is unclear whether significant improvements can also be achieved through unsupervised low-budget home-based training regimes, especially in terms of cardiac functional gains. A randomized cross-over trial was conducted to investigate the effects of a home-based unsupervised exercise training programme of moderate intensity on aerobic capacity, cardiac reserve and peak cardiac power output in healthy middle-aged volunteers. Nine subjects with no known cardiovascular diseases performed symptom-limited treadmill cardiopulmonary exercise tests after an 8-week period of exercise training, and results were compared with those obtained after a similar ‘non-exercising’ control period. Cardiac output was measured non-invasively during exercise tests using the CO₂-rebreathing method. With exercise training, resting heart rate decreased significantly from 88.3±3.4 to 78.7±3.2beatsċmin^-1 (P < 0.05), heart rate at a submaximal workload (_O2 = 1.5litresċmin^-1) decreased from 125.5±2.4 to 115.5±1.6beatsċmin^-1, and peak _O2 increased by 9% from 2.62±0.19 to 2.85±0.18litresċmin^-1 (P < 0.01). Baseline cardiac power output was 1.11±0.05W, and this remained unchanged with training. Peak cardiac power output increased by 16% from 4.1±0.3 to 4.7±0.3W (P < 0.001), and cardiac reserve increased by 21% (P < 0.01). A major contribution to these increases was from the 11% increase in stroke volume, from 100.1±5.3 to 111.2±6.2ml (P < 0.001). All subjects reported more positive perceptions of their health (P < 0.05), fitness (P < 0.01) and levels of activity (P < 0.01) after the training period. These results show that motivated subjects undergoing low-budget unsupervised home-based exercise training of moderate intensity can derive benefit in terms of symptoms, aerobic capacity and cardiac functional reserve.