EstimatingAerobic Capacity (VO2-max) using a Single-stage Step Test and Determining its Effective Factors

Maximal Aerobic Capacity (VO2-max) is an indicator of the preparedness of the cardiovascular and respiratory systems and a tool to estimate the physiological fitness of individuals for their work. This study aimed to measure the VO2-max and Physical Work Capacity (PWC) of workers at a metal industry and the factors affecting it using a single-stage step test. This cross-sectional study was conducted on 60 workers in a metal industry in Tehran, in 2017. Data collection tools were a questionnaire including separate sections asking about demographic and anthropometric (height, weight, and BMI) characteristics. Quantitative variables were recorded after being measured. The Tuxworth and Shahnawaz method and step test were used in order to estimate VO2-max and PWC. Data were analyzed using SPSS 22. The relative humidity of the place was 40% and local air pressure was 879 atmospheres. The average VO2-maxand average maximum PWC of the study population were 3.13±0.283L/min and 15.65±1.41 kcal/min, respectively. There was a significant relationship between VO2-maxusingsingle-stage step test and BMI (P=0.01), number of hours of exercise per week (P=0.009) and age (P=0.01). The step test is a rapid, easy and low-cost method to estimate physiological adaptation and PWC of individuals. Variables such asage, hours of exercise per week and BMI are effective on aerobic capacity.