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

There is evidence that multiple benefits can be obtained through exercise t raining that leads to increases in peak oxygen consumption ((V) over dot (O 2)). It is unclear whether significant improvements can also be achieved th rough unsupervised low-budget home-based training regimes, especially in te rms of cardiac functional gains. A randomized cross-over trial was conducte d to investigate the effects of a home-based unsupervised exercise training programme of moderate intensity on aerobic capacity, cardiac reserve and p eak cardiac power output in healthy middle-aged volunteers. Nine subjects w ith no known cardiovascular diseases performed symptom-limited treadmill ca rdiopulmonary exercise tests after an 8-week period of exercise training, a nd results were compared with those obtained after a similar 'non-exercisin g' control period. Cardiac output was measured non-invasively during exerci se tests using the CO2-rebreathing method. With exercise training, resting heart rate decreased significantly from 88.3 +/- 3.4 to 78.7 +/- 3.2 beats . min(-1) (P < 0.05), heart rate at a submaximal workload ((V) over dot (O2 ) = 1.5 litres . min-1) decreased from 125.5 +/- 2.4 to 115.5 +/- 1.6 beats .min(-1), and peak (V) over dot (O2) increased by 9% from 2.62 +/- 0.19 to 2.85 +/- 0.18 litres.min(-1) (P < 0.01). Baseline cardiac power output was 1.11 +/- 0.05 W, and this remained unchanged with training. Peak cardiac po wer output increased by 16% from 4.1 +/- 0.3 to 4.7 +/- 0.3 W (P < 0.001), and cardiac reserve increased by 21% (P < 0.01). A major contribution to th ese increases was from the 11% increase in stroke volume, from 100.1 +/- 5. 3 to 111.2 +/- 6.2 ml (P < 0.001). All subjects reported more positive perc eptions of their health (P < 0.05), fitness (P < 0.01) and levels of activi ty (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 capaci ty and cardiac functional reserve.