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.

Progressive increase in human skeletal muscle AMPKα2 activity and ACC phosphorylation during exercise

2002 ◽  
Vol 282 (3) ◽  
pp. E688-E694 ◽  
Author(s):  
T. J. Stephens ◽  
Z.-P. Chen ◽  
B. J. Canny ◽  
B. J. Michell ◽  
B. E. Kemp ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Human Skeletal Muscle ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Western Blots ◽  
Muscle Glycogen Content ◽  
Muscle Creatine

The effect of prolonged moderate-intensity exercise on human skeletal muscle AMP-activated protein kinase (AMPK)α1 and -α2 activity and acetyl-CoA carboxylase (ACCβ) and neuronal nitric oxide synthase (nNOSμ) phosphorylation was investigated. Seven active healthy individuals cycled for 30 min at a workload requiring 62.8 ± 1.3% of peak O2consumption (V˙o 2 peak) with muscle biopsies obtained from the vastus lateralis at rest and at 5 and 30 min of exercise. AMPKα1 activity was not altered by exercise; however, AMPKα2 activity was significantly ( P < 0.05) elevated after 5 min (∼2-fold), and further elevated ( P < 0.05) after 30 min (∼3-fold) of exercise. ACCβ phosphorylation was increased ( P < 0.05) after 5 min (∼18-fold compared with rest) and increased ( P< 0.05) further after 30 min of exercise (∼36-fold compared with rest). Increases in AMPKα2 activity were significantly correlated with both increases in ACCβ phosphorylation and reductions in muscle glycogen content. Fat oxidation tended ( P = 0.058) to increase progressively during exercise. Muscle creatine phosphate was lower ( P < 0.05), and muscle creatine, calculated free AMP, and free AMP-to-ATP ratio were higher ( P < 0.05) at both 5 and 30 min of exercise compared with those at rest. At 30 min of exercise, the values of these metabolites were not significantly different from those at 5 min of exercise. Phosphorylation of nNOSμ was variable, and despite the mean doubling with exercise, statistically significance was not achieved ( P = 0.304). Western blots indicated that AMPKα2 was associated with both nNOSμ and ACCβ consistent with them both being substrates of AMPKα2 in vivo. In conclusion, AMPKα2 activity and ACCβ phosphorylation increase progressively during moderate exercise at ∼60% of V˙o 2 peak in humans, with these responses more closely coupled to muscle glycogen content than muscle AMP/ATP ratio.

Carbohydrate ingestion influences skeletal muscle cytokine mRNA and plasma cytokine levels after a 3-h run

2003 ◽  
Vol 94 (5) ◽  
pp. 1917-1925 ◽  
Author(s):  
D. C. Nieman ◽  
J. M. Davis ◽  
D. A. Henson ◽  
J. Walberg-Rankin ◽  
M. Shute ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Maximal Oxygen Consumption ◽  
Vastus Lateralis Muscle ◽  
Cytokine Mrna ◽  
Carbohydrate Ingestion ◽  
Muscle Glycogen Content ◽  
Tnf Α

Sixteen experienced marathoners ran on treadmills for 3 h at ∼70% maximal oxygen consumption (V˙o 2 max) on two occasions while receiving 1 l/h carbohydrate (CHO) or placebo (Pla) beverages. Blood and vastus lateralis muscle biopsy samples were collected before and after exercise. Plasma was analyzed for IL-6, IL-10, IL-1 receptor agonist (IL-1ra), IL-8, cortisol, glucose, and insulin. Muscle was analyzed for glycogen content and relative gene expression of 13 cytokines by using real-time quantitative RT-PCR. Plasma glucose and insulin were higher, and cortisol, IL-6, IL-10, and IL-1ra, but not IL-8, were significantly lower postexercise in CHO vs. Pla. Change in muscle glycogen content did not differ between CHO and Pla ( P = 0.246). Muscle cytokine mRNA content was detected preexercise for seven cytokines in this order (highest to lowest): IL-15, TNF-α, IL-8, IL-1β, IL-12p35, IL-6, and IFN-γ. After subjects ran for 3 h, gene expression above prerun levels was measured for five of these cytokines: IL-1β, IL-6, and IL-8 (large increases), and IL-10 and TNF-α (small increases). The increase in mRNA (fold difference from preexercise) was attenuated in CHO (15.9-fold) compared with Pla (35.2-fold) for IL-6 ( P = 0.071) and IL-8 (CHO, 7.8-fold; Pla, 23.3-fold; P = 0.063). CHO compared with Pla beverage ingestion attenuates the increase in plasma IL-6, IL-10, and IL-1ra and gene expression for IL-6 and IL-8 in athletes running 3 h at 70%V˙o 2 max despite no differences in muscle glycogen content.

Influence of muscle glycogen availability on ERK1/2 and Akt signaling after resistance exercise in human skeletal muscle

2005 ◽  
Vol 99 (3) ◽  
pp. 950-956 ◽  
Author(s):  
Andrew Creer ◽  
Philip Gallagher ◽  
Dustin Slivka ◽  
Bozena Jemiolo ◽  
William Fink ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Muscle Glycogen ◽  
Human Skeletal Muscle ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Akt Signaling ◽  
Cellular Growth ◽  
Muscle Glycogen Content ◽  
Ribosomal S6 Kinase

Two pathways that have been implicated for cellular growth and development in response to muscle contraction are the extracellular signal-regulated kinase (ERK1/2) and Akt signaling pathways. Although these pathways are readily stimulated after exercise, little is known about how nutritional status may affect stimulation of these pathways in response to resistance exercise in human skeletal muscle. To investigate this, experienced cyclists performed 30 repetitions of knee extension exercise at 70% of one repetition maximum after a low (2%) or high (77%) carbohydrate (LCHO or HCHO) diet, which resulted in low or high (∼174 or ∼591 mmol/kg dry wt) preexercise muscle glycogen content. Muscle biopsies were taken from the vastus lateralis before, ∼20 s after, and 10 min after exercise. ERK1/2 and p90 ribosomal S6 kinase phosphorylation increased ( P ≤ 0.05) 10 min after exercise, regardless of muscle glycogen availability. Akt phosphorylation was elevated ( P < 0.05) 10 min after exercise in the HCHO trial but was unaffected after exercise in the LCHO trial. Mammalian target of rapamycin phosphorylation was similar to that of Akt during each trial; however, change or lack of change was not significant. In conclusion, the ERK1/2 pathway appears to be unaffected by muscle glycogen content. However, muscle glycogen availability appears to contribute to regulation of the Akt pathway, which may influence cellular growth and adaptation in response to resistance exercise in a low-glycogen state.

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)

Skeletal muscle GLUT-4 and glucose uptake during exercise in humans

1994 ◽  
Vol 77 (3) ◽  
pp. 1565-1568 ◽  
Author(s):  
G. McConell ◽  
M. McCoy ◽  
J. Proietto ◽  
M. Hargreaves
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Glucose Uptake ◽  
Muscle Glycogen ◽  
Protein Level ◽  
Glycogen Content ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Muscle Glycogen Content ◽  
Glut 4

The present study examined the relationship between total skeletal muscle GLUT-4 protein level and glucose uptake during exercise. Eight active non-endurance-trained men cycled at 72 +/- 1% peak pulmonary oxygen consumption for 40 min, with rates of glucose appearance and disappearance (Rd) determined by utilizing a primed continuous infusion of [3–3H]glucose commencing 2 h before exercise. Muscle glycogen content and utilization, citrate synthase activity, and total GLUT-4 protein were measured on muscle biopsy samples obtained from the vastus lateralis. A direct relationship existed between preexercise muscle glycogen content and glycogen utilization during exercise (r = 0.76, P < 0.05). Citrate synthase activity and glucose Rd at the end of exercise averaged 21.9 +/- 3.0 mumol.min-1.g-1 and 27.3 +/- 2.5 mumol.kg-1.min-1, respectively. There was a direct correlation between citrate synthase activity and GLUT-4 protein (r = 0.78, P < 0.05); however, at the end of exercise, glucose Rd was inversely related to both GLUT-4 (r = -0.89, P < 0.01) and citrate synthase activity (r = -0.72, P < 0.05). Plasma insulin, which decreased during exercise, was not related to glucose Rd. In conclusion, glucose uptake during 40 min of exercise at 72% peak pulmonary oxygen consumption was inversely related to the total muscle GLUT-4 protein level. This suggests that factors other than the total GLUT-4 protein level are important in the regulation of glucose uptake during exercise.

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.

Fiber type-specific muscle glycogen sparing due to carbohydrate intake before and during exercise

2007 ◽  
Vol 102 (1) ◽  
pp. 183-188 ◽  
Author(s):  
K. De Bock ◽  
W. Derave ◽  
M. Ramaekers ◽  
E. A. Richter ◽  
P. Hespel
Keyword(s):  
Muscle Glycogen ◽  
Glycogen Content ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Periodic Acid ◽  
Carbohydrate Intake ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Type I Fibers ◽  
Glycogen Sparing

The effect of carbohydrate intake before and during exercise on muscle glycogen content was investigated. According to a randomized crossover study design, eight young healthy volunteers ( n = 8) participated in two experimental sessions with an interval of 3 wk. In each session subjects performed 2 h of constant-load bicycle exercise (∼75% maximal oxygen uptake). On one occasion (CHO), they received carbohydrates before (∼150 g) and during (1 g·kg body weight−1·h−1) exercise. On the other occasion they exercised after an overnight fast (F). Fiber type-specific relative glycogen content was determined by periodic acid Schiff staining combined with immunofluorescence in needle biopsies from the vastus lateralis muscle before and immediately after exercise. Preexercise glycogen content was higher in type IIa fibers [9.1 ± 1 × 10−2 optical density (OD)/μm2] than in type I fibers (8.0 ± 1 × 10−2 OD/μm2; P < 0.0001). Type IIa fiber glycogen content decreased during F from 9.6 ± 1 × 10−2 OD/μm2 to 4.5 ± 1 × 10−2 OD/μm2 ( P = 0.001), but it did not significantly change during CHO ( P = 0.29). Conversely, in type I fibers during CHO and F the exercise bout decreased glycogen content to the same degree. We conclude that the combination of carbohydrate intake both before and during moderate- to high-intensity endurance exercise results in glycogen sparing in type IIa muscle fibers.

Reducing dark-cutting in pasture-fed beef steers by high-energy supplementation

2007 ◽  
Vol 47 (11) ◽  
pp. 1277 ◽  
Author(s):  
B. W. Knee ◽  
L. J. Cummins ◽  
P. J. Walker ◽  
G. A. Kearney ◽  
R. D. Warner
Keyword(s):  
Perennial Ryegrass ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Subterranean Clover ◽  
Cattle Grazing ◽  
High Energy ◽  
Stocking Rate ◽  
Muscle Glycogen Content ◽  
Feeding Regimes ◽  
Muscle Biopsies

Dark-cutting in muscles of the beef carcass is due to low muscle glycogen levels at slaughter and occurs particularly in autumn and winter in grass-fed cattle in southern Australia. The aim of these experiments was to investigate the effect of supplementary feeding of cattle grazing pasture during winter on muscle glycogen levels. The first experiment involved 70 cattle allocated to two stocking rates grazing improved perennial ryegrass and subterranean clover pastures [high stocking rate (HSR) v. low stocking rate (LSR)] by two pasture feeding regimes (control, pasture only v. pasture supplemented with a high-energy ration for 4 weeks) plus a feedlot treatment (fed high-energy ration in pens with no pasture for 11 weeks). Muscle biopsies were collected from the M. semitendinosus (ST) and M. semimembranosus (SM) muscles and analysed for muscle glycogen. The ST muscle glycogen content for supplemented animals increased (P < 0.05) over the feeding period but there was no effect (P > 0.05) of supplementation on the muscle glycogen content of the SM or on the muscle glycogen content of the ST or SM of cattle in the feedlot treatment, relative to control cattle. HSR cattle tended to have lower muscle glycogen in the ST compared to LSR cattle across both feeding regimes. The second experiment used 60 cattle allocated to two treatments (control, pasture only v. pasture supplemented with a high-energy ration for 3 weeks). The treatments were applied to cattle grazing improved perennial ryegrass and subterranean clover pastures and muscle biopsies were collected weekly from the SM and ST. Supplementation resulted in a linear increase (P < 0.05) in muscle glycogen levels over the 3 weeks in both the SM and ST muscles. These results indicate that feed quality has a major impact on muscle glycogen levels in the SM and ST of cattle destined for slaughter. At times of the year when pasture quality is poor or quantity is lacking, supplementation with a high-energy supplement has the potential to dramatically increase muscle glycogen and reduce the incidence of dark-cutting beef.

Muscle glycogen storage following prolonged exercise: effect of timing of ingestion of high glycemic index food

1997 ◽  
Vol 29 (2) ◽  
pp. 220-224 ◽  
Author(s):  
JO ANN M. PARKIN ◽  
MICHAEL F. CAREY ◽  
IVA K. MARTIN ◽  
LILLIAN STOJANOVSKA ◽  
MARK A. FEBBRAIO
Keyword(s):  
Glycemic Index ◽  
Muscle Glycogen ◽  
Prolonged Exercise ◽  
Glycogen Storage ◽  
Exercise Effect ◽  
High Glycemic Index

Creatine supplementation does not affect human skeletal muscle glycogen content in the absence of prior exercise

2008 ◽  
Vol 104 (2) ◽  
pp. 508-512 ◽  
Author(s):  
Dean A. Sewell ◽  
Tristan M. Robinson ◽  
Paul L. Greenhaff
Keyword(s):  
Skeletal Muscle ◽  
Dietary Intake ◽  
Muscle Glycogen ◽  
Human Skeletal Muscle ◽  
Glycogen Content ◽  
Creatine Supplementation ◽  
Glycogen Storage ◽  
Muscle Glycogen Content ◽  
Resting Muscle ◽  
Time Point

Due to the current lack of clarity, we examined whether 5 days of dietary creatine (Cr) supplementation per se can influence the glycogen content of human skeletal muscle. Six healthy male volunteers participated in the study, reporting to the laboratory on four occasions to exercise to the point of volitional exhaustion, each after 3 days of a controlled normal habitual dietary intake. After a familiarization visit, participants cycled to exhaustion in the absence of any supplementation (N), and then 2 wk later again they cycled to exhaustion after 5 days of supplementation with simple sugars (CHO). Finally, after a further 2 wk, they again cycled to exhaustion after 5 days of Cr supplementation. Muscle samples were taken at rest before exercise, at the time point of exhaustion in visit 1, and at subsequent visit time of exhaustion. There was a treatment effect on muscle total Cr content in Cr compared with N and CHO supplementation ( P < 0.01). Resting muscle glycogen content was elevated above N following CHO ( P < 0.05) but not after Cr. At exhaustion following N, glycogen content was no different from CHO and Cr measured at the same time point during exercise. Cr supplementation under conditions of controlled habitual dietary intake had no effect on muscle glycogen content at rest or after exhaustive exercise. We suggest that any Cr-associated increases in muscle glycogen storage are the result of an interaction between Cr supplementation and other mediators of muscle glycogen storage.

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