Abstract
The aims of this study are the following: To examine whether field tests predict cardiorespiratory fitness in people with coronary heart disease (CHD) and to determine if heart rate (HR) agreement between the first ventilatory threshold (VT(1)) and field tests is sufficient for prescribing exercise intensity. Participants randomly completed field tests and a cardiopulmonary exercise test (CPET). Linear regression models were developed to predict VT(1). Agreement between predicted and measured peak oxygen consumption (V̇O(2peak)) as well as field test terminal HR and HR at VT(1) (VT(1HR)) was assessed using Pearson correlations, Bland-Altman analyses, mean absolute percentage error (MAPE), Lin's concordance correlation coefficient (CCC), and standard error of estimate (SEE). Agreement between predicted and measured V̇O(2peak) was modest (Pearson's r = 0.27-0.77; Lin's CCC = 0.132-0.735; MAPE = 16.1-30.1%; SEE = 4.7-6.8 mL·kg(-1)·min(-1)). Agreement between field test terminal HR and VT(1HR) was moderate (Pearson's r = 0.50-0.67; Lin's CCC = 0.36-0.68; MAPE = 8.9-13.7%; SEE = 11.9-18.7 bpm; Bland-Altman 95%LOA = -3.5 to 13.7 bpm). Field tests demonstrated variable accuracy for predicting V̇O(2peak), with none meeting predefined agreement criteria. Regression models indicate field tests can estimate VT(1;) however, levels of HR agreement indicate CPET is necessary for prescribing exercise intensity.