Abstract
This systematic review and meta-analysis aims to investigate the impact of exercise snacks (ExSn), which involve incorporating short bursts of high-intensity physical activity into daily routines, on improving cardiometabolic health and body composition in adults. Six online databases [PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, and Scopus] were searched from inception through 22 May 2025, and relevant randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) were identified. Outcomes were analyzed using standardized mean differences and mean differences with 95% confidence intervals. Subgroup analyses were conducted based on physical activity levels and duration for each bout of ExSn. The GRADE scale was used to assess evidence certainty, while the revised Cochrane risk-of-bias tool (RoB 2) was used to evaluate the quality of RCTs, and the Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool was used for non-RCTs. Twelve RCTs and two non-RCTs, involving a total of 483 adults, were selected for the systematic review; 13 studies were included in the meta-analysis. Among the RCTs, 2 studies showed a high risk of bias, and 10 showed some concerns. For the non-RCTs, 1 study had a moderate risk of bias, and 1 had a serious risk of bias. The ExSn group showed significant improvements in maximal oxygen uptake (SMD = 1.43, 95% CI 0.61 to 2.25, p < 0.001) and peak power output (SMD = 0.68, 95% CI 0.00 to 1.36, p = 0.050), and reductions in total cholesterol (SMD = -0.65, 95% CI -1.18 to -0.11, p = 0.018) and LDL cholesterol (SMD = -0.65, 95% CI -1.22 to -0.09, p = 0.023). No significant differences were found for body weight, body fat, HDL cholesterol, or triglycerides. ExSn significantly enhances cardiometabolic health, especially in physically inactive adults. As a novel, time-efficient approach, ExSn can be easily integrated into daily routines, offering a practical solution for sedentary and inactive individuals or those with limited time. These findings highlight its potential as a widely applicable public health strategy, warranting further research on long-term effects and broader applications. PROSPERO Registration Number: CRD42024554446.