Although wearable activity trackers hold a promise of nudging people toward a more active lifestyle, current research reveals inconsistent findings regarding the effectiveness of them. The objectives of this paper are two-fold: (1) to synthesize evidence on the effects of wearable activity trackers for improving physical activities, and (2) to identify potential moderators of effect size. A systematic meta-analytic review was conducted. Forty-eight eligible papers based on forty-four distinct trials were identified through a systematic literature search process. Two authors independently extracted information from each study based on predefined data fields. Random-effects meta-analysis, subgroup analysis, and meta-regression analysis were employed. First, interventions with wearable activity trackers significantly increased daily steps and weekly moderate-to-vigorous physical activity but had no impact on light physical activity or sedentary behavior. Second, daily steps and weekly moderate-to-vigorous physical activity were associated with participants’ characteristics (i.e., gender, age, medical condition, and baseline physical activity level) and intervention features (i.e., sensors, modes of expert support, and intervention duration). The identified factors explained 53 % of the total variance for weekly moderate-to-vigorous physical activity. The use of wearable activity trackers effectively improves conscious exercise behavior, including daily steps and weekly moderate-to-vigorous physical activity, but not effective for modifying habitual behavior, such as light physical activity and sedentary behavior. We also explicitly show that the extent to which the interventions with wearable activity trackers help users is contingent on the type of users and the design and delivery of interventions. Future studies are called to validate the findings and to offer theoretical explanations.

中文翻译：

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用于促进身体活动的可穿戴活动追踪器：系统荟萃分析综述

尽管可穿戴活动追踪器有望推动人们采取更积极的生活方式，但目前的研究显示，关于其有效性的研究结果不一致。本文的目标有两个：（1）综合可穿戴活动追踪器对改善身体活动的影响的证据，（2）确定影响大小的潜在调节因素。进行了系统的荟萃分析审查。通过系统的文献检索过程，确定了基于 44 项不同试验的 48 篇合格论文。两位作者根据预定义的数据字段独立地从每项研究中提取信息。采用随机效应荟萃分析、亚组分析和荟萃回归分析。首先，可穿戴活动追踪器的干预显着增加了每日步数和每周中度至剧烈的体力活动，但对轻度体力活动或久坐行为没有影响。其次，每日步数和每周中等至剧烈的体力活动与参与者的特征（即性别、年龄、健康状况和基线体力活动水平）和干预特征（即传感器、专家支持模式和干预）相关期间）。已确定的因素解释了每周中度至剧烈体力活动总方差的 53%。使用可穿戴活动追踪器可以有效改善有意识的锻炼行为，包括每日步数和每周中度至剧烈的体力活动，但对于改变习惯性行为（例如轻度体力活动和久坐行为）无效。我们还明确表明，可穿戴活动追踪器的干预措施对用户的帮助程度取决于用户的类型以及干预措施的设计和实施。未来的研究需要验证研究结果并提供理论解释。