Journal of Knowledge & Health1735-577X11220160315Validity and Reliability of the Height Adjustable Step for Step Test384310.1234/knh.v11i2.1354FAGhasemHesamDept. of Occupational Health Engineering, Occupational and Environmental Health Research Center, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran.. ghasem_hesam@yahoo.comMohammad HosseinEbrahimiFaridehKhosraviRashidSattariFatemehDehghaniZahraMoradpoor201601092016030120160301Introduction: Step test is one of the indirect methods of measuring the maximum aerobic capacity. The stairs are designed with constant height in more step tests, that the biomechanical differences of height can cause a bias in the results. This study was conducted to determine the validity and reliability of the height adjustable step to step test.Methods: The minimum and maximum step height, according to the relationship in the Francis step test method was determined, and then the step was made. Intra-class Correlation Coefficient (ICC) was used to evaluate the reliability of step, after testing in 2 times, with an interval of one week on a single group. Also the Pearson correlation coefficient was used to assess the validity of the step. All analyzes were performed using SPSS software in significant level of 0.05.Results: The results of the reliability test, with an ICC correlation coefficient equal to 0.886, has confirmed the reliability of the researcher made step. Also the validity of step has been approved (P˂0.001 and r=0.737).Conclusion: The results showed that the researcher made step has a good reliability and validity to measure the amount of VO2max. These findings indicate that this tool can be used for measuring VO2max in different people.