Normative values and prediction equations for the modified incremental step test in healthy adults aged 18–83 years

Abstract

ObjectiveTo establish normative values and reference equations for predicting the number of steps and oxygen consumption (VO2) from the modified incremental step test (MIST) in healthy adults aged 18–83 years. DesignProspective observational study. ParticipantsOne hundred and ninety-four healthy adults aged 18–83 years with normal spirometry. SettingsExercise physiology laboratory of a university. MethodsParticipants underwent two MISTs (30 minutes apart). The MIST was performed on a 20-cm-high step using an externally paced rhythm imposed by audible signals, starting with 10 steps per minute and with constant increments of 1 step every 30 seconds. Main outcomesNumber of steps and VO2 obtained from MIST. ResultsNormative values were provided for males and females for each age group. The following equations were determined: number of steps = 675.113 + (66.165*sex, 0 female and 1 male) - (5.353*age) - (6.593*body mass index) (R² =0.44, P < 0.001); VO2 = 0.106 + (0.216*sex, 0 female and 1 male) - (0.008*age [years]) + (0.021*weight [kilograms]) + (0.001*number of steps) (R² =0.80, P < 0.001). ConclusionNormative values and prediction equations are proposed for the number of steps and VO2 which can be used to interpret performance on the MIST in individuals with different health conditions. These equations now need validation in other samples.