Gastric emptying of a carbohydrate-electrolyte drink during a soccer match

Purpose: To investigate the effect on gastric emptying of intermittent exer cise at varying intensities such as occurs during a soccer match. Methods: We compared the emptying rate of a carbohydrate-electrolyte (CE) drink duri ng two 15-min periods of a competitive 5-a-side indoor soccer match separat ed by 10 min and during two 15-min periods of low-intensity walking exercis e. Seven healthy male subjects, all of whom regularly played soccer, comple ted the study. Exercise intensity on each trial was calculated from heart r ate recordings, Subjects ingested 500 mL of the CE drink immediately before starting each exercise period. Before and after completing each 15-min exe rcise period, the gastric contents were aspirated and the volume recorded. Ambient room temperature ranged from 16-22 degreesC and humidity ranged fro m 57-72% on both trials. Results: Mean SD heart rate was higher during the Soccer trial than during the Walking trial at all time points, Exercise int ensity was calculated to be 54 +/- 23% and 63 +/- 20% (V)over dotO(2max), r espectively, for the first and second periods of exercise on the Soccer tri al and 13 +/-9% and 12 +/- 11% (V)over dotO(2max), respectively, for the fi rst and second periods of exercise on the Walking trial. During the first 1 5-min period of exercise, a greater (median (range)) volume of the CE drink was emptied from the stomach on the Walking trial (247 mL (102-361 mL)) th an on the Soccer trial (84 mL (17-230 mL); P=0.022). In the second exercise period, however, gastric emptying rates were not different (P=0.16) betwee n the Walking trial (247 ml, (104-363 mL)) and Soccer trial (148 mL (17-293 mL)). Conclusion: As indicated by heart rate, the, overall exercise intens ity of an indoor soccer match appears to be moderate. The pattern of activi ty during a match is intermittent with periods of low level activity punctu ated by short bursts of high-intensity sprinting. The present study demonst rates that the intensity of activity during this type of exercise is suffic ient to slow gastric emptying.