Mitchell J B, Voss K W
Department of Physical Education, Texas Christian University, Fort Worth 76129.
Med Sci Sports Exerc. 1991 Mar;23(3):314-9.
The purpose of this study was to determine the effect of ingesting approximately 800, 1200, or 1600 ml.h-1 of a carbohydrate (CHO) solution on gastric emptying (GE), ratings of stomach fullness (RF), plasma volume changes (PVC), electrolytes, fluid loss, and blood glucose (BG) during 2 h of cycling at 70% of VO2max. Eight male cyclists completed three rides during which they ingested either 11.5 (LV), 17.1 (MV), or 23 ml.kg-1.h-1 (HV) of a 7.5% CHO solution every 15 min. Blood samples were taken at 0, 60, 90, and 120 min and 15 min after the ride for the determination of PVC, sodium (Na+), potassium (K+), and BG. Body weight was recorded before and after the rides to determine dehydration. Rates of GE were determined via stomach aspiration after the rides. A significantly (P less than 0.05) greater volume of fluid was emptied in the HV trial (2268 +/- 70.8 ml) compared with the MV and LV trials (1860 +/- 72 and 1452 +/- 24 ml, respectively). The rate of GE in the MV trial was also significantly greater than in the LV trial. RF were significantly higher in the MV and HV trials compared with the LV trial throughout the rides. There were no significant differences in PVC (0.01 +/- 2.2%, 1.05 +/- 1.62%, and 0.97 +/- 1.28% for LV, MV, and HV, respectively), Na+, K+, or BG between the three trials. There was a significantly greater decrease in body weight in the LV (-0.77 +/- 0.14 kg) compared with the MV and HV trials (-0.38 +/- 0.13 and -0.14 +/- 0.14 kg).(ABSTRACT TRUNCATED AT 250 WORDS)
本研究的目的是确定在以最大摄氧量（VO2max）的70%进行2小时骑行期间，摄入约800、1200或1600毫升·小时⁻¹的碳水化合物（CHO）溶液对胃排空（GE）、饱腹感评分（RF）、血浆容量变化（PVC）、电解质、液体流失和血糖（BG）的影响。八名男性自行车运动员完成了三次骑行，期间他们每15分钟摄入11.5（低容量，LV）、17.1（中等容量，MV）或23毫升·千克⁻¹·小时⁻¹（高容量，HV）的7.5%CHO溶液。在骑行前0、60、90和120分钟以及骑行后15分钟采集血样，以测定PVC、钠（Na⁺）、钾（K⁺）和BG。记录骑行前后的体重以确定脱水情况。骑行后通过胃抽吸确定GE速率。与MV和LV试验（分别为1860±72和1452±24毫升）相比，HV试验中排空的液体量显著更多（P<0.05）（2268±70.8毫升）。MV试验中的GE速率也显著高于LV试验。在整个骑行过程中，MV和HV试验中的RF显著高于LV试验。三次试验之间的PVC（LV、MV和HV分别为0.01±2.2%、1.05±1.62%和0.97±1.28%）、Na⁺、K⁺或BG没有显著差异。与MV和HV试验（分别为-0.38±0.13和-0.14±0.14千克）相比，LV试验中体重下降显著更大（-0.77±0.14千克）。（摘要截断于250字）
