Exercise training intensity determination in cardiovascular rehabilitation: Should the guidelines be reconsidered?

Abstract

Aims In the rehabilitation of cardiovascular disease patients a correct determination of the endurance-type exercise intensity is important to generate health benefits and preserve medical safety. It remains to be assessed whether the guideline-based exercise intensity domains are internally consistent and agree with physiological responses to exercise in cardiovascular disease patients. Methods A total of 272 cardiovascular disease patients without pacemaker executed a maximal cardiopulmonary exercise test on bike (peak respiratory gas exchange ratio >1.09), to assess peak heart rate (HR peak ), oxygen uptake (VO 2peak ) and cycling power output (W peak ). The first and second ventilatory threshold (VT1 and VT2, respectively) was determined and extrapolated to %VO 2peak , %HR peak , %heart rate reserve (%HRR) and %W peak for comparison with guideline-based exercise intensity domains. Results VT1 was noted at 62 ± 10% VO 2peak , 75 ± 10% HR peak , 42 ± 14% HRR and 47 ± 11% W peak , corresponding to the high intensity exercise domain (for %VO 2peak and %HR peak ) or low intensity exercise domain (for %W peak and %HRR). VT2 was noted at 84 ± 9% VO 2peak , 88 ± 8% HR peak , 74 ± 15% HRR and 76 ± 11% W peak , corresponding to the high intensity exercise domain (for %HRR and %W peak ) or very hard exercise domain (for %HR peak and %VO 2peak ). At best (when using %W peak ) in only 63% and 72% of all patients VT1 and VT2, respectively, corresponded to the same guideline-based exercise intensity domain, but this dropped to about 48% and 52% at worst (when using %HRR and %HR peak , respectively). In particular, the patient’s VO 2peak related to differently elicited guideline-based exercise intensity domains ( P < 0.05). Conclusion The guideline-based exercise intensity domains for cardiovascular disease patients seem inconsistent, thus reiterating the need for adjustment.