Acute Effects of Exercise Snacks on Glucose and Lipid Metabolic Outcomes in Individuals with Metabolic Disorders: A...

To quantify the acute effects of exercise snacks on glucose and lipid metabolism in individuals with metabolic disorders (including those with type 2 diabetes, metabolic syndrome, and overweight or obesity) compared with sedentary behavior and continuous exercise, and to examine their effects across different exercise modalities.

Following the PRISMA 2020 guidelines, four databases (PubMed, Embase, Web of Science, and Scopus) were searched up to February 4, 2026, to identify randomized crossover trials that examined the acute effects of exercise snacks on glucose and lipid metabolism in individuals with metabolic disorders. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and the quality of evidence was assessed using the GRADE approach. The "meta" and "metafor" packages in R (version 4.5.2) were used to calculate pooled effect estimates (using Hedges' g as the effect size) and to conduct publication bias tests, subgroup analyses, and regression analyses.

The analysis included 20 randomized crossover trials (21 studies) involving 392 participants. Compared with prolonged sedentary behavior, exercise snacks significantly reduced postprandial glucose AUC (Hedges' g = -0.37, 95% CI -0.53 to -0.22, P < 0.01, I² = 6.6%, moderate certainty of evidence) and insulin AUC (Hedges' g = -0.49, 95% CI -0.68 to -0.30, P < 0.01, I² = 15.7%, moderate certainty of evidence), whereas no significant improvement was observed for triglycerides (Hedges' g = -0.014, 95% CI -0.18 to 0.15, P = 0.87, I² = 0.0%, low certainty of evidence). Compared with a single session of continuous exercise, exercise snacks showed no statistically significant differences in postprandial glucose (Hedges' g = -0.14, 95% CI -0.73 to 0.45, P = 0.64, I² = 57.6%, low certainty of evidence), insulin, or triglycerides. The included studies did not provide separate data for individuals with a confirmed diagnosis of MetS; therefore, the subgroup analysis was limited to overweight or obese individuals and those with T2DM. When stratified by study population, exercise snacks significantly reduced the postprandial glucose AUC in overweight or obese individuals (Hedges' g = -0.36, 95% CI: -0.52 to -0.20, P < 0.001), whereas the effect estimate in the T2DM group did not reach statistical significance (Hedges' g = -0.45, 95% CI: -1.47 to 0.56, P = 0.385), and the difference between the two subgroups was not significant (P between subgroups = 0.86). Insulin AUC was significantly reduced in both the overweight or obese group (Hedges' g = -0.42, 95% CI: -0.61 to -0.24, P < 0.001) and the T2DM group (Hedges' g = -1.15, 95% CI: -1.76 to -0.54, P < 0.001), and the difference between subgroups was significant (P = 0.03 between subgroups); however, the estimate for the T2DM subgroup was based on only one study. Regression analysis indicated that older participants experienced a greater reduction in insulin levels (β = -0.01, 95% CI -0.02 to 0.00, P = 0.02).

In individuals with metabolic disorders, repeatedly interrupting sedentary behavior with short bouts of mild- to moderate-intensity aerobic exercise (2-5 minutes of activity every ≤30 minutes) can acutely reduce postprandial glucose and insulin responses. A meta-regression analysis suggests that studies involving participants with a higher average age showed a greater reduction in postprandial insulin AUC. No statistically significant differences in short-term glycemic control were observed between exercise "snacks" and a single continuous exercise session; however, this comparison was based on only four studies with small sample sizes and is therefore insufficient to demonstrate the non-inferiority or equivalence of the two exercise patterns. Exercise "snacks" can serve as a low-barrier complementary strategy to regular exercise and other lifestyle management approaches.