Peak Oxygen Uptake Prediction From a Moderate, Perceptually Regulated, 1-km Treadmill Walk in Male Cardiac Patients

Abstract

In Brief PURPOSE: To determine whether a moderate 1-km treadmill walking test (1KTWT) could be used to predict peak oxygen uptake ( O2peak) in patients with cardiovascular disease. METHODS: One hundred seventy-eight male patients, aged 38 to 83 years, completed a O2peak treadmill test and a 1KTWT using a self-regulated intensity of 11 to 13 of 20 on the Borg scale. Multivariable regression analysis was used to develop equations for predicting O2peak in a development group (n = 110), both for subjects prescribed and not prescribed a β-blocking agent (BB/NBB, 66/44). These equations were then applied to a cross-validation and reproducibility group (n = 68, BB/NBB, 37/31), who completed the protocol twice within 2 weeks. RESULTS: Analysis from 1KTWT in the development group showed that age, body mass index, walking speed, and heart rate were the most potent predictors of O2peak. Measured and predicted O2peak were not significantly different, and were strongly associated among both the NBB (r = 0.81, P < .0001) and BB (r = 0.69, P < .0001) groups, with a mean residual of approximately 1.0 mL·kg−1·min−1. When applied to the cross-validation and reproducibility group, the equations similarly yielded strong associations (r = 0.64, P < 0.001 and r = 0.71, P < 0.001 for the NBB and BB groups, respectively), with no significantly differences between measured and predicted O2peak. Mean test-retest differences for measured and predicted O2peak were between 0.1 and −0.5 mL·kg−1·min−1. CONCLUSIONS: Equations developed from the 1KTWT accurately predicted O2peak in patients with cardiovascular disease. The model may represent a valid, low cost, and simple tool for indirect estimations of cardiorespiratory fitness in an outpatient setting. A 1-km treadmill walk test at an individualized, moderate intensity was employed to predict peak oxygen uptake (VO2) in patients with cardiovascular disease. The test was highly correlated with measured peak VO2, and represents a simple, low cost method for estimating functional capacity and prescribing physical activity in cardiac rehabilitation.