Appropriate selection of exercise intensity in patients with interstitial lung disease

Abstract Background Training intensities in pulmonary rehabilitation are commonly based on fixed percentages of peak heart rate (HRpeak), heart rate reserve (HRR), or peak work load (Wpeak). For patients suffering from interstitial lung disease (ILD) it is unknown, whether those intensities are appropriate when compared to individual ventilatory thresholds (VT1 and VT2) derived from cardiopulmonary exercise testing (CPET). The aim of this study was to compare fixed HR percentages with HRs at VT1 and VT2. Study Design and Methods A total of 120 subjects, 80 ILD patients and 40 healthy controls, underwent a symptom-limited CPET. From the ILD patient, 32 suffered from idiopathic pulmonary fibrosis (IPF), 37 from connective tissue disease (CTD) and 11 from sarcoidosis. Results HRs at fixed percentages, i.e., at 70%HRpeak, at 70%Wpeak and at 60%HRR were significantly lower in the ILD patients compared to the control group. Large percentages of HR values at 70%Wpeak and 60%HRR ranged between the HRs at VT1 and VT2 in ILD subgroups and controls as well. HRs at 70%HRpeak were lower than HRs at VT1 in 66% of the IPF patients, 54% of the CTD patients and 55% of patients with sarcoidosis compared to 18% in the control group. Discussion Our findings demonstrate a considerable scattering of fixed HR percentages compared to HRs at the individual VTs derived from CPET in ILD patients. Thus, the use of HRs at the individual VTs is recommended for appropriate prescription of exercise intensity in pulmonary rehabilitation of ILD patients.