Optimal Frequency of Interrupting Prolonged Sitting for Cardiometabolic Health: A Systematic Review and Meta‐Analysis of Randomized Crossover Trials

Increasing evidence highlights the efficacy of interruptions in prolonged sitting (i.e., activity/sedentary breaks) for improving cardiometabolic health, but precise conclusions and recommendations regarding the optimal interruption frequency remain poorly defined. This systematic review and meta-analysis aimed to directly compare the effect of different frequencies of interrupting prolonged sitting on cardiometabolic health and to determine potential moderators. Randomized crossover trials with at least two frequency interruptions compared to a prolonged sitting condition were identified via systematic review. We compared the acute effects of high-frequency (≤ 30 min per bout, HF) versus low-frequency (> 30 min per bout, LF) interruption protocols on various cardiometabolic health outcomes via three-level meta-analysis with pooled effects evaluated within a random-effects model and exploration of potential sources of heterogeneity through subgroup analyses. The quality of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Thirteen studies with 211 participants (24-66 years, 41% female) were included. When comparing HF to LF condition, the HF had a significantly greater reduction in glucose (9 studies [n = 740]; Hedge's g = -0.30, 95% CI [-0.57, -0.03], p = 0.03; I