Accuracy of Xiaomi Mi Band 5 to measure step count and energy expenditure in older adults under free-living conditions

Abstract Purpose To analyze the validity and accuracy of the low-cost fitness tracker Xiaomi Mi Band 5 wristband to assess step count and energy expenditure in older adults under free-living conditions. Methods The data were recorded from 38 older adults (> 60 years old) under free-living conditions for seven consecutive days. The Mi Band 5 wristband was compared to the ActiGraph GT3X+. Results For step count, the Xiaomi Mi Band 5 showed a very strong positive correlation with the ActiGraph GT3X+ (Spearman’s r = 0.93, p = 0.001), excellent agreement (ICC = 0.94; 95% CI = 0.89–0.97), and excellent accuracy according to MAPE (− 3.7%). For calorie expenditure, the Mi Band 5 showed a strong positive correlation with ActiGraph measurements (Spearman’s r = 0.63, p = 0.001), but low agreement (ICC = 0.39; 95% CI = − 0.11–0.67) and poor accuracy according to MAPE (95.46%). Conclusion The results suggest that Xiaomi Mi Band 5 provides accurate step count measurements under free living conditions, offering reliable information on overall physical activity in older adults. However, it is not sufficiently accurate for assessing calorie expenditure. Therefore, it may be a useful low-cost tool for monitoring and promoting increased physical activity among older adults. Trial registration This study was registered at Registro Brasileiro de Ensaios Clínicos (ReBEC) platform ( https://ensaiosclinicos.gov.br/rg/RBR-4gdzh2 ) (register n: RBR-4gdzh2). Date of registration: 09/18/2020.