Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion

1988 ◽  
Vol 64 (4) ◽  
pp. 1480-1485 ◽  
Author(s):  
J. L. Ivy ◽  
A. L. Katz ◽  
C. L. Cutler ◽  
W. M. Sherman ◽  
E. F. Coyle
Keyword(s):  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Glycogen Synthesis ◽  
Glycogen Storage ◽  
Cycle Ergometer ◽  
Carbohydrate Ingestion ◽  
Exercise Effect ◽  
Exercise Muscle ◽  
Reduced Rate ◽  
Carbohydrate Supplement

The time of ingestion of a carbohydrate supplement on muscle glycogen storage postexercise was examined. Twelve male cyclists exercised continuously for 70 min on a cycle ergometer at 68% VO2max, interrupted by six 2-min intervals at 88% VO2max, on two separate occasions. A 25% carbohydrate solution (2 g/kg body wt) was ingested immediately postexercise (P-EX) or 2 h postexercise (2P-EX). Muscle biopsies were taken from the vastus lateralis at 0, 2, and 4 h postexercise. Blood samples were obtained from an antecubital vein before and during exercise and at specific times after exercise. Muscle glycogen immediately postexercise was not significantly different for the P-EX and 2P-EX treatments. During the first 2 h postexercise, the rate of muscle glycogen storage was 7.7 mumol.g wet wt-1.h-1 for the P-EX treatment, but only 2.5 mumol.g wet wt-1.h-1 for the 2P-EX treatment. During the second 2 h of recovery, the rate of glycogen storage slowed to 4.3 mumol.g wet wt-1.h-1 during treatment P-EX but increased to 4.1 mumol.g wet wt-1.h-1 during treatment 2P-EX. This rate, however, was still 45% slower (P less than 0.05) than that for the P-EX treatment during the first 2 h of recovery. This slower rate of glycogen storage occurred despite significantly elevated plasma glucose and insulin levels. The results suggest that delaying the ingestion of a carbohydrate supplement post-exercise will result in a reduced rate of muscle glycogen storage.

Carbohydrate Ingestion during Exercise: Effects on Muscle Glycogen Resynthesis after Exercise

1993 ◽  
Vol 3 (4) ◽  
pp. 418-430 ◽  
Author(s):  
Jeffrey J. Zachwieja ◽  
David L. Costill ◽  
William J. Fink
Keyword(s):  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Cycle Ergometer ◽  
Serum Glucose ◽  
Carbohydrate Ingestion ◽  
Glycogen Resynthesis ◽  
Carbohydrate Feeding ◽  
Muscle Biopsies ◽  
Carbohydrate Solution ◽  
Carbohydrate Supplement

To determine the effect of carbohydrate feeding on muscle glycogen resynthesis, 8 male cyclists pedaled for 2 hrs on a cycle ergometer at 70% of VO2max while consuming either a 10% carbohydrate solution (CHO) or a nonnutritive sweet placebo (No CHO). Muscle biopsies were obtained from the vastus lateralis prior to, immediately postexercise, and at 2,4, and 24 hrs of recovery. Blood samples were taken before and at the end of exercise, and at specified times during recovery. During both trials food intake was withheld for the first 2 hrs of recovery, but at 2 hrs postexercise a 24% carbohydrate solution was ingested. The rate of muscle glycogen resynthesis during the first 2 hrs of recovery was similar for the CHO and No CHO trials. Following ingestion of the 24% carbohydrate supplement, the rates of muscle glycogen resynthesis increased similarly in both trials. These similar rates of resynthesis following ingestion of the carbohydrate supplement were obtained despite significantly greater serum glucose and insulin levels during the No CHO trial. The results indicate that the carbohydrate feedings taken during exercise had little effect on postexercise muscle glycogen resynthesis.

Muscle glycogen storage after different amounts of carbohydrate ingestion

1988 ◽  
Vol 65 (5) ◽  
pp. 2018-2023 ◽  
Author(s):  
J. L. Ivy ◽  
M. C. Lee ◽  
J. T. Brozinick ◽  
M. J. Reed
Keyword(s):  
Blood Glucose ◽  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Recovery Period ◽  
Glycogen Storage ◽  
Carbohydrate Ingestion ◽  
Blood Samples ◽  
Glucose Polymer ◽  
Glycogen Stores ◽  
Muscle Biopsies

The purpose of this study was to determine whether the rate of muscle glycogen storage could be enhanced during the initial 4-h period postexercise by substantially increasing the amount of the carbohydrate consumed. Eight subjects cycled for 2 h on three separate occasions to deplete their muscle glycogen stores. Immediately and 2 h after exercise they consumed either 0 (P), 1.5 (L), or 3.0 g glucose/kg body wt (H) from a 50% glucose polymer solution. Blood samples were drawn from an antecubital vein before exercise, during exercise, and throughout recovery. Muscle biopsies were taken from the vastus lateralis immediately, 2 h, and 4 h after exercise. Blood glucose and insulin declined significantly during exercise in each of the three treatments. They remained below the preexercise concentrations during recovery in the P treatment but increased significantly above the preexercise concentrations during the L and H treatments. By the end of the 4 h-recovery period, blood glucose and insulin were still significantly above the preexercise concentrations in both treatments. Muscle glycogen storage was significantly increased above the basal rate (P, 0.5 mumol.g wet wt-1.h-1) after ingestion of either glucose polymer supplement. The rates of muscle glycogen storage, however, were not different between the L and H treatments during the first 2 h (L, 5.2 +/- 0.9 vs. H, 5.8 +/- 0.7 mumol.g wet wt-1.h-1) or the second 2 h of recovery (L, 4.0 +/- 0.9 vs. H, 4.5 +/- 0.6 mumol.g wet wt-1. h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Early postexercise muscle glycogen recovery is enhanced with a carbohydrate-protein supplement

2002 ◽  
Vol 93 (4) ◽  
pp. 1337-1344 ◽  
Author(s):  
John L. Ivy ◽  
Harold W. Goforth ◽  
Bruce M. Damon ◽  
Thomas R. McCauley ◽  
Edward C. Parsons ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Plasma Insulin ◽  
Vastus Lateralis ◽  
Glycogen Storage ◽  
Caloric Content ◽  
Resonance Spectroscopy ◽  
Ordered Design ◽  
Glycogen Stores ◽  
Insulin Responses ◽  
Carbohydrate Supplement

In the present study, we tested the hypothesis that a carbohydrate-protein (CHO-Pro) supplement would be more effective in the replenishment of muscle glycogen after exercise compared with a carbohydrate supplement of equal carbohydrate content (LCHO) or caloric equivalency (HCHO). After 2.5 ± 0.1 h of intense cycling to deplete the muscle glycogen stores, subjects ( n = 7) received, using a rank-ordered design, a CHO-Pro (80 g CHO, 28 g Pro, 6 g fat), LCHO (80 g CHO, 6 g fat), or HCHO (108 g CHO, 6 g fat) supplement immediately after exercise (10 min) and 2 h postexercise. Before exercise and during 4 h of recovery, muscle glycogen of the vastus lateralis was determined periodically by nuclear magnetic resonance spectroscopy. Exercise significantly reduced the muscle glycogen stores (final concentrations: 40.9 ± 5.9 mmol/l CHO-Pro, 41.9 ± 5.7 mmol/l HCHO, 40.7 ± 5.0 mmol/l LCHO). After 240 min of recovery, muscle glycogen was significantly greater for the CHO-Pro treatment (88.8 ± 4.4 mmol/l) when compared with the LCHO (70.0 ± 4.0 mmol/l; P = 0.004) and HCHO (75.5 ± 2.8 mmol/l; P = 0.013) treatments. Glycogen storage did not differ significantly between the LCHO and HCHO treatments. There were no significant differences in the plasma insulin responses among treatments, although plasma glucose was significantly lower during the CHO-Pro treatment. These results suggest that a CHO-Pro supplement is more effective for the rapid replenishment of muscle glycogen after exercise than a CHO supplement of equal CHO or caloric content.

Muscle glycogen storage after prolonged exercise: effect of the glycemic index of carbohydrate feedings

1993 ◽  
Vol 75 (2) ◽  
pp. 1019-1023 ◽  
Author(s):  
L. M. Burke ◽  
G. R. Collier ◽  
M. Hargreaves
Keyword(s):  
Glycemic Index ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Glycogen Storage ◽  
Carbohydrate Intake ◽  
Total Carbohydrate ◽  
Muscle Glycogen Content ◽  
Exercise Effect ◽  
Muscle Biopsies

The effect of the glycemic index (GI) of postexercise carbohydrate intake on muscle glycogen storage was investigated. Five well-trained cyclists undertook an exercise trial to deplete muscle glycogen (2 h at 75% of maximal O2 uptake followed by four 30-s sprints) on two occasions, 1 wk apart. For 24 h after each trial, subjects rested and consumed a diet composed exclusively of high-carbohydrate foods, with one trial providing foods with a high GI (HI GI) and the other providing foods with a low GI (LO GI). Total carbohydrate intake over the 24 h was 10 g/kg of body mass, evenly distributed between meals eaten 0, 4, 8, and 21 h postexercise. Blood samples were drawn before exercise, immediately after exercise, immediately before each meal, and 30, 60, and 90 min post-prandially. Muscle biopsies were taken from the vastus lateralis immediately after exercise and after 24 h. When the effects of the immediate postexercise meal were excluded, the totals of the incremental glucose and insulin areas after each meal were greater (P < or = 0.05) for the HI GI meals than for the LO GI meals. The increase in muscle glycogen content after 24 h of recovery was greater (P = 0.02) with the HI GI diet (106 +/- 11.7 mmol/kg wet wt) than with the LO GI diet (71.5 +/- 6.5 mmol/kg). The results suggest that the most rapid increase in muscle glycogen content during the first 24 h of recovery is achieved by consuming foods with a high GI.

Eccentric exercise-induced muscle damage impairs muscle glycogen repletion

1987 ◽  
Vol 63 (1) ◽  
pp. 252-256 ◽  
Author(s):  
K. P. O'Reilly ◽  
M. J. Warhol ◽  
R. A. Fielding ◽  
W. R. Frontera ◽  
C. N. Meredith ◽  
...  
Keyword(s):  
Eccentric Exercise ◽  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Young Male ◽  
Exercise Bout ◽  
Cycle Ergometer ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Metabolic Intensity ◽  
Exercise Muscle

Five healthy untrained young male subjects were studied before, immediately after, and 10 days after a 45-min bout of eccentric exercise on a cycle ergometer (201 W). The subjects were sedentary at all other times and consumed a eucaloric meat-free diet. Needle biopsies of the vastus lateralis muscle were examined for intracellular damage and glycogen content. Immediately after exercise, muscle samples showed myofibrillar tearing and edema. At 10 days, there was myofibrillar necrosis, inflammatory cell infiltration, and no evidence of myofibrillar regeneration. Glycogen utilization during the exercise bout was 33 mmol glycosyl units/kg muscle, consistent with the metabolic intensity of 44% of maximal O2 uptake; however, the significant glycogen use by type II fibers contrasted with concentric exercise performed at this intensity. At 10 days after exercise, muscle glycogen was still depleted, in both type I and II fibers. It is possible that the alterations in muscle ultrastructures were related to the lack of repletion of muscle glycogen. Damage produced by eccentric exercise was more persistent than previously reported, indicating that more than 10 days may be necessary for recovery of muscle ultrastructure and carbohydrate reserves.

Effect of alcohol intake on muscle glycogen storage after prolonged exercise

2003 ◽  
Vol 95 (3) ◽  
pp. 983-990 ◽  
Author(s):  
Louise M. Burke ◽  
Greg R. Collier ◽  
Elizabeth M. Broad ◽  
Peter G. Davis ◽  
David T. Martin ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Alcohol Intake ◽  
Vastus Lateralis ◽  
Glycogen Synthesis ◽  
Recovery Period ◽  
Optimal Recovery ◽  
Glycogen Storage ◽  
Serum Triglycerides ◽  
Nutrition Practices ◽  
Insulin Responses

We studied the effects of alcohol intake on postexercise muscle glycogen restoration with samples from vastus lateralis being collected immediately after glycogen-depleting cycling and after a set recovery period. Six well-trained cyclists undertook a study of 8-h recovery (2 meals), and another nine cyclists undertook a separate 24-h protocol (4 meals). In each study, subjects completed three trials in crossover order: control (C) diet [meals providing carbohydrate (CHO) of 1.75 g/kg]; alcohol-displacement (A) diet (1.5 g/kg alcohol displacing CHO energy from C) and alcohol + CHO (AC) diet (C + 1.5 g/kg alcohol). Alcohol intake reduced postmeal glycemia especially in A trial and 24-h study, although insulin responses were maintained. Alcohol intake increased serum triglycerides, particularly in the 24-h study and AC trial. Glycogen storage was decreased in A diets compared with C at 8 h (24.4 ± 7 vs. 44.6 ± 6 mmol/kg wet wt, means ± SE, P < 0.05) and 24 h (68 ± 5 vs. 82 ± 5 mmol/kg wet wt, P < 0.05). There was a trend to reduced glycogen storage with AC in 8 h (36.2 ± 8 mmol/kg wet wt, P = 0.1) but no difference in 24 h (85 ± 9 mmol/kg wet wt). We conclude that 1) the direct effect of alcohol on postexercise glycogen synthesis is unclear, and 2) the main effect of alcohol intake is indirect, by displacing CHO intake from optimal recovery nutrition practices.

Impaired muscle glycogen storage after muscle biopsy

1988 ◽  
Vol 64 (5) ◽  
pp. 2245-2248 ◽  
Author(s):  
D. L. Costill ◽  
D. R. Pearson ◽  
W. J. Fink
Keyword(s):  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Glycogen Storage ◽  
Vastus Lateralis Muscle ◽  
Muscle Sample ◽  
Initial Biopsy ◽  
Glycogen Repletion ◽  
Exercise Muscle ◽  
The Right ◽  
Male Subjects

To assess the effects of repeated needle biopsies on the rate of muscle glycogen repletion, eight male subjects were studied immediately after and 2 days after an exhaustive cycling bout. A single biopsy was obtained from the right vastus lateralis muscle immediately after an exhaustive cycling bout. Two days later, a sample was taken 1 cm lateral or medial to sample A. In four of these subjects, additional biopsies were taken 3 cm distal and proximal. A control specimen was also taken from the left leg 2 days after the exercise. Ten days after the exercise, muscle was again sampled from each leg of these four subjects. Analysis of these samples revealed that the initial biopsy impaired glycogen storage in the muscle taken 1 cm medial or lateral to the previous site. This reduction in glycogen storage was most pronounced in the first 2 days after the exercise. Samples taken distal and proximal to the initial biopsy contained, on the average, less glycogen than the contralateral leg, but these differences were only significantly different in the distal muscle sample. Alteration in muscle glycogen storage was seen to persist for 10 days after the first biopsy, suggesting that care must be taken in selecting the site for repeated biopsies from the same muscle.

Muscle glycogen storage postexercise: effect of mode of carbohydrate administration

1989 ◽  
Vol 66 (2) ◽  
pp. 720-726 ◽  
Author(s):  
M. J. Reed ◽  
J. T. Brozinick ◽  
M. C. Lee ◽  
J. L. Ivy
Keyword(s):  
Blood Glucose ◽  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Recovery Period ◽  
Insulin Response ◽  
Exercise Bout ◽  
Glycogen Storage ◽  
Glycogen Stores ◽  
Muscle Biopsies ◽  
Carbohydrate Supplement

The primary purpose of this study was to determine whether gastric emptying limits the rate of muscle glycogen storage during the initial 4 h after exercise when a carbohydrate supplement is provided. A secondary purpose was to determine whether liquid (L) and solid (S) carbohydrate (CHO) feedings result in different rates of muscle glycogen storage after exercise. Eight subjects cycled for 2 h on three separate occasions to deplete their muscle glycogen stores. After each exercise bout they received 3 g CHO/kg body wt in L (50% glucose polymer) or S (rice/banana cake) form or by intravenous infusion (I; 20% sterile glucose). The L and S supplements were divided into two equal doses and administered immediately after and 120 min after exercise, whereas the I supplement was administered continuously during the first 235 min of the 240-min recovery period. Blood samples were drawn from an antecubital vein before exercise, during exercise, and throughout recovery. Muscle biopsies were taken from the vastus lateralis immediately after and 120 and 240 min after exercise. Blood glucose and insulin declined during exercise and increased significantly above preexercise levels during recovery in all treatments. The increase in blood glucose during the I treatment, however, was three times greater than during the L or S treatments. The average insulin response of the L treatment (61.7 +/- 4.9 microU/ml) was significantly greater than that of the S treatment (47.5 +/- 4.2 microU/ml) but not that of the I (55.3 +/- 4.5 microU/ml) treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of carbohydrate ingestion on exercise metabolism

1988 ◽  
Vol 65 (4) ◽  
pp. 1553-1555 ◽  
Author(s):  
M. Hargreaves ◽  
C. A. Briggs
Keyword(s):  
Muscle Glycogen ◽  
Venous Blood ◽  
Cycle Ergometer ◽  
Strenuous Exercise ◽  
Carbohydrate Ingestion ◽  
Ergometer Exercise ◽  
Glucose Polymer ◽  
Before And After ◽  
Plasma Insulin Levels ◽  
Glycogen Utilization

Five male cyclists were studied during 2 h of cycle ergometer exercise (70% VO2 max) on two occasions to examine the effect of carbohydrate ingestion on muscle glycogen utilization. In the experimental trial (CHO) subjects ingested 250 ml of a glucose polymer solution containing 30 g of carbohydrate at 0, 30, 60, and 90 min of exercise; in the control trial (CON) they received an equal volume of a sweet placebo. No differences between trials were seen in O2 uptake or heart rate during exercise. Venous blood glucose was similar before exercise in both trials, but, on average, was higher during exercise in CHO [5.2 +/- 0.2 (SE) mmol/l] compared with CON (4.8 +/- 0.1, P less than 0.05). Plasma insulin levels were similar in both trials. Muscle glycogen levels were also similar in CHO and CON both before and after exercise; accordingly, there was no difference between trials in the amount of glycogen used during the 2 h of exercise (CHO = 62.8 +/- 10.1 mmol/kg wet wt, CON = 56.9 +/- 10.1). The results of this study indicate that carbohydrate ingestion does not influence the utilization of muscle glycogen during prolonged strenuous exercise.

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