Effect of acute postprandial exercise on continuous glucose monitoring outcomes in type 2 diabetes: A systematic review and meta-analysis of crossover trials.

To investigate the effects of acute postprandial exercise on continuous glucose monitoring (CGM) parameters in individuals with type 2 diabetes mellitus (T2DM), and to identify moderators influencing these outcomes. PubMed and Web of Science were searched until June 20, 2026. Randomized (RCT) and non-randomized (non-RCT) crossover trials examining postprandial exercise in adults with T2DM were included. Seventeen studies met the inclusion criteria. Acute postprandial exercise significantly reduced 24-hour mean glucose (Hedges' g = -0.30, 95% CI: -0.42 to -0.18, p < 0.001), time above range (TAR; Hedges' g = -0.36, 95% CI: -0.51 to -0.22, p < 0.001), glucose standard deviation (Hedges' g = -0.39, 95% CI: -0.59 to -0.19, p = 0.006), mean amplitude of glycemic excursions (MAGE; Hedges' g = -0.30, 95% CI: -0.47 to -0.13, p = 0.006), and breakfast incremental area under the curve (iAUC; Hedges' g = -0.35, 95% CI: -0.57 to -0.12, p = 0.020). Effects did not differ significantly by exercise modality for any outcome (all Q_M p > 0.05). Exercise initiated > 60 min post-meal yielded the largest reductions in 24-hour mean glucose (Hedges' g = -0.41, p < 0.001) and TAR (Hedges' g = -0.50, p = 0.004), though between-timing subgroup differences were not statistically significant (all Q_M p > 0.05). Breakfast iAUC showed the strongest postprandial effects, attenuating to non-significant at lunch (Hedges' g = -0.19) and dinner (Hedges' g = 0.03), indicating a time-of-day gradient (breakfast × timing Q_M = 8.47, p = 0.015). Exploratory meta-regression of pre-specified continuous moderators (session duration, exercise intensity, baseline HbA1C, percent male) identified no significant effects after cluster-robust correction. Acute postprandial exercise produces modest improvements in glycemic control and variability in adults with T2DM, with effects consistent across exercise modalities and strongest when performed after breakfast, supporting meal-timing-specific exercise prescriptions.