Reliability and Accuracy of 2-Minute Step Test in Active and Sedentary Lean Adults.

OBJECTIVE: The purpose of this study was to evaluate the intrarater and interrater reliability of the 2-minute step test (2MST) in active and sedentary lean adults and to identify the test cutoff point to differentiate active from sedentary individuals.

METHODS: This observational study involved 4 mixed-sex groups (each with 50 lean participants): group 1, sedentary and aged 18 to 24 years; group 2, active and aged 18 to 24 years; group 3, sedentary and aged 25 to 44 years; and group 4, active and aged 25 to 44 years. The 2MST was administered independently by 2 examiners (with 3 months' training) at 2 different times, with a 7-day interval. Habitual physical activity was evaluated by means of the Baecke Questionnaire (BQ). In statistical analysis, the Pearson correlation coefficient was used to verify the correlation between the 2MST and BQ; intraclass correlation coefficients (ICC2,3 ) were used to determine the intrarater and interrater reliability of the 2MST; and the receiver operating characteristic curve was used to identify the accuracy of the 2MST.

RESULTS: Excellent intrarater and interrater reliability were found for all 4 groups (intraclass correlation coefficients ≥ 0.83). Correlating the 2MST score with the BQ score, a significant, positive, weak correlation was observed (r = 0.344, P < .001). For differentiating active from sedentary individuals, the 2MST showed low accuracy (area under the curve = 0.671), with 61% sensitivity and 67% specificity.

CONCLUSION: This study showed that the 2MST is a reliable test with a low amount of inherent error. There was a significant correlation between the 2MST and usual physical activity measured, and slight accuracy in differentiating active from sedentary individuals.