Nomura Sayaka, Sumi Daichi, Nagatsuka Haruna, Suzuki Tomotaka, Goto Kazushige
Graduate School of Sport and Health Science, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577, Japan.
Research Center for Urban Health and Sports, Osaka Metropolitan University, Osaka, Japan.
Eur J Appl Physiol. 2025 Jan;125(1):25-35. doi: 10.1007/s00421-024-05523-1. Epub 2024 Oct 25.
The present study examined the effects of gastric emptying rate and intestinal cell damage following a single session of endurance exercise under "hypoxic" or "normoxic" conditions at the same relative intensity. Eleven healthy males performed two trials on different days, consisting of a 60 min run on a treadmill at 70% maximal running velocity (vMax) while inspiring hypoxic (FO: 14.5%; HYP) or normoxic air (FO: 20.9%; NOR). The average running velocity was 11.4 ± 0.7 km/h in NOR and 10.8 ± 0.5 km/h in HYP, respectively. Venous blood samples were collected to evaluate plasma intestinal fatty acid binding protein (I-FABP) as an indicator of exercise-induced intestinal cell damage. The gastric emptying rate was determined by the C-sodium acetate breath test. Running velocities at 70% vMax and arterial oxygen saturation were significantly lower under HYP than NOR (p < 0.001). Peak heart rate and rating of perceived exertion during exercise did not differ significantly between the trials. Maximum C excretion time (an indication of the gastric emptying rate) was significantly delayed in the HYP (NOR: 38.5 ± 5.0 min, HYP: 45.5 ± 9.6 min; p = 0.010). Furthermore, the score of nausea increased slightly, but increased significantly after exercise only in the HYP (p = 0.04). However, exercise-induced changes in plasma I-FABP, adrenaline, and noradrenaline concentrations did not differ significantly between the two trials. These results suggest that endurance exercise under hypoxic conditions impairs digestive function in the stomach compared to exercise under normoxic conditions performed at the same relative intensity.
本研究考察了在相同相对强度下，“低氧”或“常氧”条件下单次耐力运动后胃排空率和肠细胞损伤的影响。11名健康男性在不同日期进行了两项试验，包括在跑步机上以最大跑步速度（vMax）的70%进行60分钟跑步，同时吸入低氧空气（氧含量：14.5%；HYP）或常氧空气（氧含量：20.9%；NOR）。NOR组的平均跑步速度为11.4±0.7千米/小时，HYP组为10.8±0.5千米/小时。采集静脉血样以评估血浆肠脂肪酸结合蛋白（I-FABP），作为运动诱导肠细胞损伤的指标。通过C-醋酸钠呼气试验测定胃排空率。在HYP条件下，70%vMax时的跑步速度和动脉血氧饱和度显著低于NOR组（p<0.001）。两次试验中运动期间的峰值心率和主观用力程度评分无显著差异。HYP组的最大C排泄时间（胃排空率指标）显著延迟（NOR组：38.5±5.0分钟，HYP组：45.5±9.6分钟；p=0.010）。此外，恶心评分略有增加，但仅在HYP组运动后显著增加（p=0.04）。然而，两次试验中运动诱导的血浆I-FABP、肾上腺素和去甲肾上腺素浓度变化无显著差异。这些结果表明，与在相同相对强度下的常氧条件下运动相比，低氧条件下的耐力运动损害了胃的消化功能。
