Teste de degrau de seis minutos no sobrepeso e obesidade: validação, confiabilidade e equação de predição

Abstract

The objective of this study was to evaluate the construct validation and intra-rater reproducibility of the 6-minute step test (6MST) and develop a prediction equation for the step test performance in overweight and obese individuals. A total of 35 individuals were analyzed and divided into two groups: obese/overweight and control group. The 6MST and the 6-minute walk test (6MWT) were performed on different days. An isokinetic dynamometer was used to assess the lower limb muscle strength. A moderate positive correlation between the 6MST and 6MWT performances was found in the obese/overweight group (r = 0.501; p = 0.01). Reproducibility in the obese/overweight group was excellent for both performance and cardiovascular variables (intraclass correlation coefficient (ICC)>0.8; p<0.000), with the exception of the diastolic blood pressure (DBP) immediately after, which showed very good reproducibility (ICC) = 0.79; p<0.000). The following prediction equation was developed in the obese/overweight group: number of steps climbed = 85.847 + 0.482 x (peak knee extension torque). The 6MST is a valid, reproducible and viable alternative to assess functional exercise capacity in obese and overweight young people. The results showed that the lower limb muscle strength is able to predict performance on the 6MST.Keywords: validation study, reproducibility of results, obesity, exercise test, muscle strength.