Professorship of Sport Equipment and Materials, Department of Mechanical Engineering, Technical University of Munich, Boltzmannstraße 15, D-85747 Garching, Germany.
Int J Environ Res Public Health. 2019 Aug 22;16(17):3037. doi: 10.3390/ijerph16173037.
Activity trackers are a simple and mostly low-priced method to capture physiological parameters. Despite the high number of wrist-worn devices, there is a lack of scientific validation. The purpose of this study was to assess whether the activity trackers represent a valid alternative to gold-standard methods in terms of estimating energy expenditure (EE) and maximum oxygen uptake (VO). Twenty-four healthy subjects participated in this study. In total, five commercially available wrist-worn devices were tested with regard to their validity of EE and/or VO. Estimated values were compared with indirect calorimetry. Validity of the activity trackers was determined by paired sample t-tests, mean absolute percentage errors (MAPE), Intraclass Correlation Coefficient, and Bland-Altman plots. Within the tested devices, differences in scattering in VO and EE could be observed. This results in a MAPE > 10% for all evaluations, except for the VO-estimation of the Garmin Forerunner 920XT (7.3%). The latter significantly underestimates the VO (t(23) = -2.37, = 0.027), whereas the Garmin Vivosmart HR significantly overestimates the EE (t(23) = 2.44, = 0.023). The tested devices did not show valid results concerning the estimation of VO and EE. Hence, the current wrist-worn activity trackers are most likely not accurate enough to be used for neither purposes in sports, nor in health care applications.
活动追踪器是一种简单且价格相对较低的方法，可以用来捕捉生理参数。尽管有大量的腕戴设备，但缺乏科学验证。本研究的目的是评估活动追踪器在估计能量消耗 (EE) 和最大摄氧量 (VO) 方面是否可以替代金标准方法。 24 名健康受试者参加了这项研究。总共测试了五种市售的腕戴设备，以评估它们在 EE 和/或 VO 方面的有效性。估计值与间接测热法进行比较。活动追踪器的有效性通过配对样本 t 检验、平均绝对百分比误差 (MAPE)、组内相关系数和 Bland-Altman 图来确定。在所测试的设备中，可以观察到 VO 和 EE 的估计值存在差异。这导致所有评估的 MAPE > 10%，除了 Garmin Forerunner 920XT 的 VO 估计值（7.3%）。后者显著低估了 VO（t(23) = -2.37， = 0.027），而 Garmin Vivosmart HR 则显著高估了 EE（t(23) = 2.44， = 0.023）。测试的设备在 VO 和 EE 的估计方面没有显示出有效的结果。因此，目前的腕戴式活动追踪器可能不够准确，既不能用于运动目的，也不能用于医疗保健应用。
