Background: The 6-min walk test (6MWT) is a simple, inexpensive, reliable, and reproducible test that provides a reasonable estimate of the cardiorespiratory fitness (CRF). We aimed to assess the reliability and reproducibility of a self-administered 6MWT in asymptomatic adults using a free smartphone app. Methods: In the 1st phase, 93 participants underwent a supervised 6MWT (6MWTsup) in a 30 m indoor corridor, using a triaxial accelerometer and their smartphones to compare the total step counts and to develop a 6-min walk distance (6MWD) prediction equation. In the 2nd phase, 25 participants performed the 6MWTsup and two self-administered 6MWTs outdoors (6MWTsa1 and 6MWTsa2, at least 48 h apart) using a free smartphone app. Results: The agreement between accelerometer- and app-based total step counts was limited (mean difference, −58.7 steps (−8.7%): 95% confidence interval, −326.5 (−46.8%) to 209.1 (29.3%)). The best algorithm for predicting the 6MWTsupm included: 795.456 + (0.815 heightm app-steps) − (1.620 ageyears) − (3.005 weightkg) − (1.155 app-steps), R2 = 0.609). The intraclass correlation coefficient between 6MWTsa2 and 6MWTsa1 was excellent (0.91: 0.81–0.96). The coefficient of variation was 6.4%. The agreement between the two self-administered tests was narrow (−1.9 (0.2%) meters: −57.4 (−9.5%) to 61.3 (9.9%)). Conclusions: The self-administered 6MWT has excellent reliability and reproducibility in asymptomatic adults, being a valuable tool for assessing CRF in community-based interventions.

Introdução: O incremental shuttle walk test (ISWT) pode estar mais bem correlacionado com o nível de atividade física diária (NAFVD) comparado ao teste de caminhada de 6 minutos (TC6). Objetivo: Avaliar as correlações entre o NAFVD e as distâncias percorridas no TC6 e ISWT. Métodos: Selecionamos 29 adultos e idosos assintomáticos por conveniência. Estatura e peso foram coletados para cálculo do IMC. Todos foram submetidos aos testes de caminhada duas vezes em dias alternados. Mensuramos a pressão arterial, frequência cardíaca, dispneia e fadiga de membros inferiores antes e após os testes. O NAFVD foi avaliado por meio de um acelerômetro uniaxial e pelo questionário de atividade física (IPAQ). Resultados: Após análise de regressão múltipla, apenas a distância do ISWT foi determinante para número de passos diários obtidos pela acelerometria, explicando 26% da variabilidade total dessa variável. Conclusão: O ISWT se mostrou válido para estimar o NAFVD de maneira mais adequada quando comparado ao TC6.

Introduction: Previous studies suggested that body weight is a strong predictor for postural balance. High body mass index (BMI) presented an association with increased postural sway. However, it seems controversial since studies reported no difference between obese and control group regarding the position of the center of pressure in static postural balance (PB). Also, there is a lack of investigations about the impact of obesity on PB, free of the confound effect of cardiometabolic risk. Objective: The aim of this study was to evaluate the effects of obesity in static PB and occurrence of falls in asymptomatic adults and older adults over 40 years old. Method: The PB of 624 subjects divided into quartiles for BMI, waist-to-hip ratio, waist-to-height and fat body mass as percentage (%FBM) was assessed with and without vision using a force platform. An MANOVA was used to determine if there were differences between quartiles and a logistic regression analysis adjusted for confounders variables were applied to determine the obesity role in the occurrence of falls. Results: We found weak to moderate bivariate correlations between obesity and static PB, which became non-significant after adjustment. We found significant differences between first and fourth quartiles, especially using %FBM. Obesity was not related to the occurrence of falls since the odds ratio values became non-significant for all the indices of obesity after adjustment. Conclusion: Obesity presents little influence on maintaining static PB and seems not to determine the occurrence of falls among subjects over 40 years old.