EFFECT OF THE TIMING OF INGESTION OF AN EVENING MEAL FOLLOWING AN INTENSE BOUT OF EXERCISE ON BLOOD GLUCOSE RESPONSE ON THE NEXT DAY EARLY IN THE MORNING

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09680083
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 体育学
• Research Institution: UNIVERSITY OF TSUKUBA
• Principal Investigator: SATITOH Shinich UNIVERSITY OF TSUKUBA,INSTITUTE OF HEALTH AND SPORT SCIENCES,ASSOCIATE PROFESSOR, 体育科学系, 助教授 (80114081)
• Project Period (FY): 1997 – 1998
• Keywords: MEAL TIMING / MUSCLE / GLYCOGEN REPLETION / POSTEXERCISE / BLOOD GLUCOSE RESPONSE

Research Abstract

The influence of the time of ingestion of an evening meal following an intense bout of exercise on both muscle glycogen storage and blood glucose response on the next day early in the morning (12 h postexercise) was examined, In the first study, eleven healthy males were subjected to a 10 km run for 50 min pace following resistance exercise (bench press and half squat) at an intensity of 80% of one repetition maximum for 3 sets. An evening meal (73% carbohydrate, 18% fat, 9% protein ; percent of energy) was consumed within 1 h postexercise (1 P-EX) or from 3 h postexercise (3P-EX). Five subjects participated on two separate occasions and the remaining 6 subjects were divided randomly into either 1 P-EX or 3P-EX.Muscle biopsies were taken from the vastus lateralis immediately and 12 h postexercise. Muscle glycogen contents immediately postexercise were not significantly different between the 1 P-EX and the 3P-EX (mean*SD, 1P-EX vs. 3P-EX : 58.9*11.8 vs. 58.9*27.3 mmol/kg wet wt, n=5 ; 5 6.4*15.3 vs. 60.0*25.3 mmol/kg wet wt, n=8). Muscle glycogen contents 12 h postexercise increased significantly in the 1 P-EX (81.0*20.0 mmol/kg wet wt, n=5, p<0.05 ; 84.2*22.6 mmot/kg wet wt, n=8, p<0.05) but not in the 3P-EX (62.5*24.0 mg/g wet wt, n=5 ; 67.3*20.8 mmol/kg wet wt, n=8). However, there was no difference in muscle glycogen contents 12 h postexercise between the two groups (1P-EX vs. 3P-EX : 81.0*20.0 vs. 62.5*24.0 mg/g wet wt, n=5 ; 84.2*22.6 vs. 67.3*20.8 mmol/kg wet wt, n=8). There was significant difference in the rate of glycogen repletion between the 1 P-EX and the 3P- (1 P-EX vs. 3P-EX : 2.28*2.0 vs. 0.30*2.87 mmol/kg wet wt/1 2h, n=5, p<0.05 ; 2.32*2.48 vs.0.62*2.30 mmol/kg wet wt/12h, n=8, p<0.1). These results suggest that compared with delaying the ingestion of a meal postexercise, the immediate ingestion of a meal postexercise will lead to more of a good chance of successful recovery of muscle glycogen store at. 12 h postexercise, In the second study, seven males were subjected to the same exercise and meal program as those in the first study. Blood glucose response following breakfast on the next day was examined at 0, 15, 30, 60, 90 min after meal. However, there was no difference in blood glucose responses between the two timings of an evening meal.