Efficacy of activity tracker-based interventions and their behavioral components in promoting physical activity and reducing sedentary behavior in older adults: a systematic review of randomized controlled trials

Older adults often exhibit insufficient physical activity (PA) and sedentary behavior (SB), which contributes to chronic disease, functional decline, and reduced independence. From a public health perspective, low-threshold interventions are needed to promote PA and reduce SB in older adults. Wearable activity trackers offer a promising strategy by providing real-time feedback and integrating behavior change techniques (BCTs). However, evidence regarding their efficacy in older adults is still limited and inconsistent. A systematic review of randomized controlled trials (RCTs) was conducted to evaluate the efficacy of activity trackers in increasing PA and reducing SB in older adults. This review extended previous research by examining the behavioral intervention components in activity trackers. In addition, it assessed a broad range of PA and SB outcomes, categorizing them according to intervention duration to differentiate between short- (≤ 3 months), medium- (> 3–6 months), and long-term effects (> 6 months). Eligible studies met the following criteria: (a) RCT; (b) older adults (≥ 60 years or mean age ≥ 60 years minus 1 SD) not recruited for specific diseases; (c) use of an activity tracker ≥ 2 weeks; (d) comparison with at least one control group; and (e) report of PA or SB outcomes. Four databases (CENTRAL, PubMed, SPORTDiscus, Web of Science) and additional sources were screened. Risk of bias was assessed using the Cochrane RoB 2 tool. Eighteen RCTs (N = 2,841) met the inclusion criteria. Most studies reported positive effects of activity trackers on PA, particularly regarding steps per day and intensity-related PA outcomes, with effects observed in the short- and medium-term. For SB, some studies indicated a reduction in self-reported SB, whereas no improvements were reported for objectively measured SB. Most interventions combined activity trackers with multiple BCTs, most frequently goal setting, self-monitoring, and feedback on behavior. Interventions using these components more consistently demonstrated positive outcomes, indicating that specific BCTs may facilitate behavior change. Activity trackers can promote PA in older adults, particularly when combined with behavioral strategies. However, their impact on objectively measured SB and long-term outcomes remains unclear. Future interventions should explicitly target SB, align BCTs with SB-related goals, and promote long-term engagement among older adults.