Supplementary information files for Postprandial glucose responses to standardised meals consumed after moderate- and high-intensity exercise bouts across standard school days in healthy adolescents

Supplementary files for article Postprandial glucose responses to standardised meals consumed after moderate- and high-intensity exercise bouts across standard school days in healthy adolescents <br> Exercise-induced moderation of postprandial glycaemia in adolescents is unclear and has not been examined under free-living conditions. We assessed the effect of moderate-intensity exercise (MIE) and high-intensity intermittent exercise (HIIE) bouts on subsequent postprandial glycaemic responses across three standard school days. Fourteen healthy adolescents (13 ± 1 years) completed three conditions in the following order across consecutive days: MIE, 30-min continuous brisk walking; CON, no-exercise control; HIIE, 30-min of 10 × 30-s sprints interspersed with 2.5-min brisk walking bouts. Participants consumed three standardised meals (breakfast, lunch and dinner) at standardised times. Interstitial glucose, energy intake, sedentary time and physical activity were assessed under free-living conditions. Linear mixed models compared glucose outcomes between conditions, and Cohen’s d effect sizes were calculated. Although non-significant, the reduction in post-breakfast glucose iAUC was moderate for MIE (-0.24 mmol·L-1; P = 0.59; d = 0.77) and large for HIIE (-0.26 mmol·L-1; P = 0.44; d = 0.86) compared with CON. Non-significant, moderate (0.37 mmol·L-1; P = 0.22; d = 0.70) and large (0.42 mmol·L-1; P = 0.20; d = 0.81) increases in post-lunch glucose iAUC were observed for MIE and HIIE compared with CON. Nevertheless, the 24-h mean glucose was stable at ~5.4 mmol·L-1 across conditions. The glycaemic variability indices calculated over 24-h after the onset of exercise for each condition including standard deviation (P = 0.59) and mean amplitude of glycaemic excursion (P = 0.82) were not different between conditions. Thirty-minute bouts of MIE and HIIE did not change postprandial glycaemia or 24-h glycaemic variability significantly in the small sample of healthy adolescents. However, the moderate and large effect sizes suggest both MIE and HIIE reduced breakfast glucose iAUC compared with CON, yet led to increases in post-lunch iAUC in the two exercise conditions. The mismatch between the probability values and effect sizes was a consequence of our COVID-reduced sample. The ramifications of these exercise effects are unclear and need to be confirmed in a larger sample of adolescents.

本补充文件配套学术论文为《健康青少年在校常规日间完成中等强度运动与高强度间歇运动后进食标准化餐食的餐后血糖反应》
目前青少年餐后血糖的运动调控效应尚不明确，且尚未在自由生活状态下开展相关研究。本研究在三个常规在校日间，评估了中等强度运动（moderate-intensity exercise, MIE）与高强度间歇运动（high-intensity intermittent exercise, HIIE）对后续餐后血糖反应的影响。14名健康青少年（年龄13±1岁）在连续三天内按以下顺序完成三种实验条件：中等强度运动组（MIE）：30分钟持续快走；无运动对照组（no-exercise control, CON）：无运动对照；高强度间歇运动组（HIIE）：30分钟训练，包含10组30秒冲刺跑，组间穿插2.5分钟快走。受试者在标准化时间进食三份标准化餐食（早餐、午餐与晚餐）。本研究在自由生活状态下评估了受试者的间质葡萄糖（interstitial glucose）、能量摄入、久坐时间与身体活动水平。采用线性混合模型（linear mixed models）比较不同实验条件下的血糖结局，并计算了科恩d效应量（Cohen’s d effect sizes）。尽管差异无统计学意义，但与对照组相比，中等强度运动组的早餐后血糖增量曲线下面积（incremental area under the curve, iAUC）降幅中等（-0.24 mmol·L⁻¹；P=0.59；d=0.77），高强度间歇运动组的降幅较大（-0.26 mmol·L⁻¹；P=0.44；d=0.86）。与对照组相比，中等强度运动组与高强度间歇运动组的午餐后血糖iAUC出现无统计学意义的中等幅度升高（0.37 mmol·L⁻¹；P=0.22；d=0.70）与大幅度升高（0.42 mmol·L⁻¹；P=0.20；d=0.81）。不过，所有实验条件下的24小时平均血糖均稳定在约5.4 mmol·L⁻¹。各实验条件下，运动开始后24小时内计算的血糖变异性指标包括标准差（standard deviation, P=0.59）与血糖波动平均幅度（mean amplitude of glycaemic excursion, P=0.82）在组间均无显著差异。在本次小样本健康青少年受试者中，30分钟的中等强度运动与高强度间歇运动均未显著改变餐后血糖水平或24小时血糖变异性。不过，中等与大幅度的效应量提示，与对照组相比，中等强度运动与高强度间歇运动均降低了早餐后血糖iAUC，但却使两个运动组的午餐后血糖iAUC出现升高。概率值与效应量之间的不一致，源于本研究因新冠疫情缩减的样本量。上述运动效应的实际影响尚不明确，需在更大样本的青少年群体中进一步验证。