Development of a metabolic equation for the NuStep recumbent stepper in older adults

The purpose of this study was to develop an accurate metabolic equation for estimating steady-state oxygen consumption (VO2) during submaximal NuStep exercise. Adults (N = 40; M age = 64.0 yr., SD = 6.5; M height = 170.1 cm, SD = 9.1; M weight = 85.7 kg, SD = 19.9) performed two randomized testing sessions. Each session consisted of six stages with combinations of four workloads (1, 3, 5, and 7) at 3 cadences (60, 80, and 100 steps/min.). Multiple regression analysis to predict steady-state VO2 from NuStep workload (W), NuStep steps/min., and subject body mass resulted in the following model (R2 = .73): Steady-state VO2 = 3.5 + 0.016 (W* steps/min.) + 0.092 (steps/min.) - 0.053 (weight). The standard error of the estimate and total error for the prediction of steady-state VO2 under all NuStep workload conditions were 2.3 mL/kg/min. and 2.4 mL/kg/ min., respectively. The standard error of the estimate and total error values are similar to those previously reported in the literature regarding the accuracy of metabolic equations for other exercise modalities. These findings support the use of the equation developed to predict steady-state VO2 for NuStep exercise in older adult clientele.