A systems model of training for patients in phase 2 cardiac rehabilitation

Background The aim of this study was to apply a systems model of training for athletes in patients with coronary artery disease (CAD) undergoing phase 2 cardiac rehabilitation. Methods Data from six patients with CAD undergoing 20 conventional training sessions were used to test this model. The method required daily training quantification using heart rate, and regular assessment of real exercise tolerance using a constant-duration test. Convolution of training quantity with real exercise tolerance was provided for every patient model exercise tolerance, by minimizing the residual sum of squares. Results The results showed that application of the systems model of training to the six patients resulted in a strong fit between real and model exercise tolerances: r2 = 0.77, 0.79, 0.83, 0.84, 0.85 and 0.92, respectively (P < 0.05). Discussion Moreover, the systems model admitted for all patients corresponded to one first-order transfer function, which was fitness. This result was in contrast with the systems models reported in athletes and in a patient with CAD undergoing phase 3 cardiac rehabilitation which were found to include two first-order transfer functions: fitness and fatigue, simultaneously. Conclusion The systems model of training of patients with CAD undergoing phase 2 suggested two practical consequences: first, the improvement of exercise tolerance is directly related to training, and consequently second, patients who enter immediately phase 3 training may prevent a decrease in their exercise tolerance.