The incremental shuttle walk test in Brazilian older adults

Abstract

Background: Despite widespread uses of the incremental shuttle walk test distance (ISWD), there are no reference equations for predicting it. Objectives: We aimed to evaluate ISWD in healthy subjects and to establish reference equation for its prediction. Methods: One hundred and thirty one Brazilian individuals (61 males; 59 ± 10 years) performed two walk tests in a 10-m long corridor. We assessed height, weight, body mass index, forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and self-reported physical activity (RPA). Results: Mean ISWD was greater in males than in females (606 ± 167 vs. 443 ± 117 m; p < 0.001). ISWD correlated significantly (p < 0.05) with age (r = -0.51), height (r = 0.54), and weight (r = 0.20). A predictive model including age, height, weight and gender explained 50.3% of the ISWD variance. In an additional group of 20 subjects prospectively studied, the difference between measured and predicted ISWD was not statistically significant (534 ± 84 vs. 552 ± 87 m, respectively), representing 97 ± 12% of the predicted value calculated with our reference equation for ISWD. Conclusions: This reference equation including demographic and anthropomorphic attributes could be useful for interpreting the walking performance of patients with chronic diseases that affect exercise capacity. (AU)