Background Advances in the device and smartphone technology have resulted in a convenient option for providing physical activity strategies; this is especially important during the coronavirus disease 2019 pandemic. Objective The purpose of this meta-analysis is to evaluate the efficacy of wearable and smartphone-based interventions to promote physical activity and improve quality of life and cardiovascular health outcomes among overweight/obese adults. Data sources We searched relevant databases up to 18 November 2021 for conducting a systematic review and meta-analysis of randomized controlled trials lasting 4 or more weeks that investigated the impacts of wearables and smartphone applications on physical activity, quality of life and health outcomes. Results Twenty-six studies including 2373 participants were included. There was a significant pooled standard mean differences (SMD) for the comparison between intervention versus control in steps per day (SMD: 0.54; p = 0.0003), moderate-to-vigorous physical activity (SMD: 0.47; p = 0.02), quality of life (SMD: 0.33; p = 0.0006), body weight (mean difference (MD), -1.61 kg; p = 0.009), and BMI (MD, -0.59 kg/m2; p = 0.04). There were no significant differences between the intervention and control groups for systolic and diastolic blood pressure and resting heart rate (all p > 0.05). Conclusion Our findings suggest that wearable and smartphone-based interventions are effective strategies in promoting physical activity and can provide a direct contact line to health professionals.

It is shown that Milne models (a subclass of FLRW spacetimes with negative spatial curvature) are nonlinearly stable in the set of solutions to the Einstein-Vlasov-Maxwell system, describing universes with ensembles of collisionless self-gravitating, charged particles. The system contains various slowly decaying borderline terms in the mutually coupled equations describing the propagation of particles and Maxwell fields. The effects of those terms are controlled using a suitable hierarchy based on the energy density of the matter fields.