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)

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)

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.

Influence of carbohydrate dosage on exercise performance and glycogen metabolism

1989 ◽  
Vol 67 (5) ◽  
pp. 1843-1849 ◽  
Author(s):  
J. B. Mitchell ◽  
D. L. Costill ◽  
J. A. Houmard ◽  
W. J. Fink ◽  
D. D. Pascoe ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Vastus Lateralis ◽  
Venous Blood ◽  
Glycogen Metabolism ◽  
Cycle Ergometer ◽  
Work Output ◽  
O2 Consumption ◽  
Total Work ◽  
Blood Samples ◽  
Muscle Biopsies

This study was undertaken to examine the effects of ingestion of carbohydrate (CHO) solutions of 0 (WP), 6 (CHO-6), 12 (CHO-12), and 18 g CHO/100 ml (CHO-18) on performance and muscle glycogen use. Ten trained cyclists performed five 120-min cycling trials. The first 105 min of each trial was at 70% of maximal O2 consumption (VO2max), and the final 15 min was an all-out performance ride on an isokinetic cycle ergometer equipped to measure total work output. In one of the trials (CHO-12I) the submaximal portion of the ride consisted of seven 15-min rides at 70% of VO2max with a 3-min rest between each ride. Every 15 min the men consumed 8.5 ml.kg-1.h-1 (approximately 150 ml) of one of the four test solutions. Venous blood samples were obtained every 15 min for glucose and insulin. Muscle biopsies were obtained from the vastus lateralis at 0 and 105 min in the WP and the CHO-12 continuous and intermittent trials. Biopsy samples were assayed for glycogen and sectioned and stained for myosin adenosinetriphosphatase and glycogen for single fiber depletion measurements. There were no differences in glycogen use (86.7 +/- 6.0, 75.5 +/- 7.9, and 83.5 +/- 5.5 mmol/kg for the WP, CHO-12C, and CHO-12I, respectively) or depletion patterns between the WP and the two CHO-12 trials. Blood glucose was significantly elevated in both the CHO-12 trials and in the CHO-18 trial compared with the WP trial.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

The Effect of Preexercise Carbohydrate Status on Resistance Exercise Performance

1997 ◽  
Vol 7 (3) ◽  
pp. 185-196 ◽  
Author(s):  
Joel B. Mitchell ◽  
Paul C. DiLauro ◽  
Francis X. Pizza ◽  
Daniel L. Cavender
Keyword(s):  
Blood Glucose ◽  
Resistance Exercise ◽  
Muscle Glycogen ◽  
Exercise Performance ◽  
Quadriceps Muscle ◽  
Cycle Ergometry ◽  
Blood Samples ◽  
Glycogen Stores ◽  
Carbohydrate Status

The purpose of this study was to determine the effect of a high vs. a low preexercise carbohydrate (CHO) diet on performance during multiple sets of resistance exercise. Eleven resistance-trained males performed cycle ergometry to deplete quadriceps muscle glycogen stores, followed by 48 hr of a high (HICHO) or a low (LOCHO) CHO diet. Subjects then performed five sets each of squats, leg presses, and knee extensions (resistance = 15 RM) to failure. Blood samples were taken before and during exercise for determination of glucose and lactate (LA). No differences in performance (repetitions X weight lifted) were observed (HICHO = 15,975±1,381 and LOCHO = 15,723±1,231 kg). Blood glucose was significantly higher after exercise for HICHO compared to LOCHO (HICHO = 4.8 ± 0.2 vs. LOCHO = 3.9 ± 0.2 mmol·L−1). No differences in LA accumulation were observed. The data indicated that preexercise CHO status did not affect resistance exercise performance. Further, the differences in blood glucose and the similarity in LA responses suggest that glycolysis was maintained in the LOCHO condition, and there may have been an increased reliance on blood glucose when preexercise CHO status was low.

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.

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.

Skeletal muscle GLUT-4 and postexercise muscle glycogen storage in humans

1996 ◽  
Vol 80 (2) ◽  
pp. 411-415 ◽  
Author(s):  
M. McCoy ◽  
J. Proietto ◽  
M. Hargreaves
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Citrate Synthase ◽  
Glycogen Synthase ◽  
Vastus Lateralis ◽  
Recovery Period ◽  
Glycogen Storage ◽  
Glucose Disposal ◽  
Glut 4 ◽  
Wet Weight

The purpose of this study was to examine the relationship between skeletal muscle GLUT-4 protein and postexercise glycogen storage in human subjects fed adequate carbohydrate. Eleven men completed 2 h of cycling, and a biopsy of the vastus lateralis was performed immediately after exercise cessation for the determination of muscle GLUT-4 protein and glycogen concentrations, glycogen synthase activity, and citrate synthase activity. The subjects ingested meals providing 2.0 g carbohydrate/kg body weight at 0, 2, and 4 h postexercise, and a second biopsy was performed 6 h postexercise. Muscle glycogen concentration increased significantly during the 6-h recovery period (glycogen immediately postexercise, 27.2 +/- 5.4 mmol/kg wet weight; glycogen storage, 52.4 +/- 2.9 mmol x kg wet weight-1 x 6 h-1; P<0.05). Glycogen storage during recovery was directly related to GLUT-4 protein (2.20 +/- 0.33 arbitrary standard units; r = 0.63; P<0.05) and inversely related to glycogen immediately postexercise (r = -0.70; P < 0.05). A direct correlation existed between glycogen storage during recovery and the activity of the I form of glycogen synthase (r = 0.60; P < 0.05). These results suggest that muscle GLUT-4 protein concentration, as well as factors relating to glucose disposal, may affect postexercise glycogen storage in humans fed adequate carbohydrate.

scholarly journals Regulation of muscle glycogenolytic flux during intense aerobic exercise after caffeine ingestion

1998 ◽  
Vol 275 (2) ◽  
pp. R596-R603 ◽  
Author(s):  
Alan Chesley ◽  
Richard A. Howlett ◽  
George J. F. Heigenhauser ◽  
Eric Hultman ◽  
Lawrence L. Spriet
Keyword(s):  
Aerobic Exercise ◽  
Muscle Glycogen ◽  
Glycogen Phosphorylase ◽  
Vastus Lateralis ◽  
Energy Status ◽  
Caffeine Ingestion ◽  
Sparing Effect ◽  
Muscle Biopsies ◽  
Glycogen Sparing ◽  
Epinephrine Concentration

This study examined the effects of caffeine (Caf) ingestion on muscle glycogen use and the regulation of muscle glycogen phosphorylase (Phos) activity during intense aerobic exercise. In two separate trials, 12 untrained males ingested either placebo (Pl) or Caf (9 mg/kg body wt) 1 h before cycling at 80% maximum O2 consumption (V˙o 2 max) for 15 min. Muscle biopsies were obtained from the vastus lateralis at 0, 3, and 15 min of exercise. In this study, glycogen “sparing” was defined as a 10% or greater reduction in muscle glycogen use during exercise after Caf ingestion compared with Pl. Muscle glycogen use decreased by 28% (Pl 255 ± 38 vs. Caf 184 ± 24 mmol/kg dry muscle) after Caf in six subjects [glycogen sparers (Sp)] but was unaffected by Caf in six other subjects [nonsparers (NSp), Pl 210 ± 35 vs. Caf 214 ± 37 mmol/kg dry muscle]. In both groups, Caf significantly increased resting free fatty acid concentration, significantly increased epinephrine concentration by twofold during exercise, and increased the Phos a mole fraction at 3 min of exercise compared with Pl, although not significantly. Caf improved the energy status of the muscle during exercise in the Sp group: muscle phosphocreatine (PCr) degradation was significantly reduced (Pl 47.9 ± 3.6 vs. Caf 40.4 ± 6.7 mmol/kg dry muscle at 3 min) and the accumulations of free ADP and free AMP (Pl 6.8 ± 1.3 vs. Caf 3.1 ± 1.4 μmol/kg dry muscle at 3 min; Pl 8.7 ± 0.8 vs. Caf 4.7 ± 1.1 μmol/kg dry muscle at 15 min) were significantly reduced. Caf had no effect on these measurements in the NSp group. It is concluded that the Caf-induced decrease in flux through Phos (glycogen-sparing effect) is mediated via an improved energy status of the muscle in the early stages of intense aerobic exercise. This may be related to an increased availability of fat and/or ability of mitochondria to oxidize fat during exercise preceded by Caf ingestion. It is presently unknown why the glycogen-sparing effect of Caf does not occur in all untrained individuals during intense aerobic exercise.

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