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Glycogen supercompensation

Paul A Roberts, John Fox, Nicholas Peirce, Simon W Jones, Anna Casey, Paul L Greenhaff
Muscle glycogen availability can limit endurance exercise performance. We previously demonstrated 5 days of creatine (Cr) and carbohydrate (CHO) ingestion augmented post-exercise muscle glycogen storage compared to CHO feeding alone in healthy volunteers. Here, we aimed to characterise the time-course of this Cr-induced response under more stringent and controlled experimental conditions and identify potential mechanisms underpinning this phenomenon. Fourteen healthy, male volunteers cycled to exhaustion at 70 % VO2peak...
August 2016: Amino Acids
Louise M Burke
During the period 1985-2005, studies examined the proposal that adaptation to a low-carbohydrate (<25 % energy), high-fat (>60 % energy) diet (LCHF) to increase muscle fat utilization during exercise could enhance performance in trained individuals by reducing reliance on muscle glycogen. As little as 5 days of training with LCHF retools the muscle to enhance fat-burning capacity with robust changes that persist despite acute strategies to restore carbohydrate availability (e.g., glycogen supercompensation, carbohydrate intake during exercise)...
November 2015: Sports Medicine
A M Blanco, M Gómez-Boronat, J Pérez-Maceira, M J Mancebo, M Aldegunde
Brain glycogen is depleted when used as an emergency energy substrate. In mammals, brain glycogen levels rebound to higher than normal levels after a hypoglycemic episode and a few hours after refeeding or administration of glucose. This phenomenon is called glycogen supercompensation. However, this mechanism has not been investigated in lower vertebrates. The aim of this study was therefore to determine whether brain glycogen supercompensation occurs in the rainbow trout brain. For this purpose, short-term brain glucose and glycogen contents were determined in rainbow trout after being subjected to the following experimental conditions: i) a 5-day or 10-day fasting period and refeeding; ii) a single injection of insulin (4 mg kg(-1)) and refeeding; and iii) sustained swimming and injection of glucose (500 mg kg(-1))...
September 2015: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
Eric A F Herbst, Rebecca E K MacPherson, Paul J LeBlanc, Brian D Roy, Nam Ho Jeoung, Robert A Harris, Sandra J Peters
During recovery from glycogen-depleting exercise, there is a shift from carbohydrate oxidation to glycogen resynthesis. The activity of the pyruvate dehydrogenase (PDH) complex may decrease to reduce oxidation of carbohydrates in favor of increasing gluconeogenic recycling of carbohydrate-derived substrates for this process. The precise mechanism behind this has yet to be elucidated; however, research examining mRNA content has suggested that the less-abundant pyruvate dehydrogenase kinase-4 (PDK4) may reduce PDH activation during exercise recovery...
January 15, 2014: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
Jason J Winnick, Zhibo An, Guillaume Kraft, Christopher J Ramnanan, Jose M Irimia, Marta Smith, Margaret Lautz, Peter J Roach, Alan D Cherrington
The purpose of this study was to determine the effect of liver glycogen loading on net hepatic glycogen synthesis during hyperinsulinemia or hepatic portal vein glucose infusion in vivo. Liver glycogen levels were supercompensated (SCGly) in two groups (using intraportal fructose infusion) but not in two others (Gly) during hyperglycemic-normoinsulinemia. Following a 2-h control period during which fructose infusion was stopped, there was a 2-h experimental period in which the response to hyperglycemia plus either 4× basal insulin (INS) or portal vein glucose infusion (PoG) was measured...
January 2013: Diabetes
José M Irimia, Jordi Rovira, Jakob N Nielsen, Mario Guerrero, Jørgen F P Wojtaszewski, Roser Cussó
BACKGROUND: Glycogen-depleting exercise can lead to supercompensation of muscle glycogen stores, but the biochemical mechanisms of this phenomenon are still not completely understood. METHODS: Using chronic low-frequency stimulation (CLFS) as an exercise model, the tibialis anterior muscle of rabbits was stimulated for either 1 or 24 hours, inducing a reduction in glycogen of 90% and 50% respectively. Glycogen recovery was subsequently monitored during 24 hours of rest...
2012: PloS One
Thomas E Jensen, Erik A Richter
Utilization of carbohydrate in the form of intramuscular glycogen stores and glucose delivered from plasma becomes an increasingly important energy substrate to the working muscle with increasing exercise intensity. This review gives an update on the molecular signals by which glucose transport is increased in the contracting muscle followed by a discussion of glycogen mobilization and synthesis by the action of glycogen phosphorylase and glycogen synthase, respectively. Finally, this review deals with the signalling relaying the well-described increased sensitivity of glucose transport to insulin in the post-exercise period which can result in an overshoot of intramuscular glycogen resynthesis post exercise (glycogen supercompensation)...
March 1, 2012: Journal of Physiology
Takashi Matsui, Taro Ishikawa, Hitoshi Ito, Masahiro Okamoto, Koshiro Inoue, Min-Chul Lee, Takahiko Fujikawa, Yukio Ichitani, Kentaro Kawanaka, Hideaki Soya
Brain glycogen localized in astrocytes, a critical energy source for neurons, decreases during prolonged exhaustive exercise with hypoglycaemia. However, it is uncertain whether exhaustive exercise induces glycogen supercompensation in the brain as in skeletal muscle. To explore this question, we exercised adult male rats to exhaustion at moderate intensity (20 m min(-1)) by treadmill, and quantified glycogen levels in several brain loci and skeletal muscles using a high-power (10 kW) microwave irradiation method as a gold standard...
February 1, 2012: Journal of Physiology
Akiko Sano, Keiichi Koshinaka, Natsuki Abe, Masashi Morifuji, Jinichiro Koga, Emi Kawasaki, Kentaro Kawanaka
A single bout of prolonged endurance exercise stimulates glucose transport in skeletal muscles, leading to post-exercise muscle glycogen supercompensation if sufficient carbohydrate is provided after the cessation of exercise. Although we recently found that short-term sprint interval exercise also stimulates muscle glucose transport, the effect of this type of exercise on glycogen supercompensation is uncertain. Therefore, we compared the extent of muscle glycogen accumulation in response to carbohydrate feeding following sprint interval exercise with that following endurance exercise...
January 2012: Journal of Physiological Sciences: JPS
Gülin Öz, Nolawit Tesfaye, Anjali Kumar, Dinesh K Deelchand, Lynn E Eberly, Elizabeth R Seaquist
Supercompensated brain glycogen may contribute to the development of hypoglycemia unawareness in patients with type 1 diabetes by providing energy for the brain during periods of hypoglycemia. Our goal was to determine if brain glycogen content is elevated in patients with type 1 diabetes and hypoglycemia unawareness. We used in vivo (13)C nuclear magnetic resonance spectroscopy in conjunction with [1-(13)C]glucose administration in five patients with type 1 diabetes and hypoglycemia unawareness and five age-, gender-, and body mass index-matched healthy volunteers to measure brain glycogen content and metabolism...
February 2012: Journal of Cerebral Blood Flow and Metabolism
Asker E Jeukendrup
Endurance sports are increasing in popularity and athletes at all levels are looking for ways to optimize their performance by training and nutrition. For endurance exercise lasting 30 min or more, the most likely contributors to fatigue are dehydration and carbohydrate depletion, whereas gastrointestinal problems, hyperthermia, and hyponatraemia can reduce endurance exercise performance and are potentially health threatening, especially in longer events (>4 h). Although high muscle glycogen concentrations at the start may be beneficial for endurance exercise, this does not necessarily have to be achieved by the traditional supercompensation protocol...
2011: Journal of Sports Sciences
Jason J Winnick, Zhibo An, Christopher J Ramnanan, Marta Smith, Jose M Irimia, Doss W Neal, Mary Courtney Moore, Peter J Roach, Alan D Cherrington
OBJECTIVE: The objective of this study was to determine how increasing the hepatic glycogen content would affect the liver's ability to take up and metabolize glucose. RESEARCH DESIGN AND METHODS: During the first 4 h of the study, liver glycogen deposition was stimulated by intraportal fructose infusion in the presence of hyperglycemic-normoinsulinemia. This was followed by a 2-h hyperglycemic-normoinsulinemic control period, during which the fructose infusion was stopped, and a 2-h experimental period in which net hepatic glucose uptake (NHGU) and disposition (glycogen, lactate, and CO(2)) were measured in the absence of fructose but in the presence of a hyperglycemic-hyperinsulinemic challenge including portal vein glucose infusion...
February 2011: Diabetes
Sarah E Canada, Staci A Weaver, Shannon N Sharpe, Bartholomew A Pederson
Brain glycogen is proposed to function under both physiological and pathological conditions. Pharmacological elevation of this glucose polymer in brain is hypothesized to protect neurons against hypoglycemia-induced cell death. Elevation of brain glycogen levels due to prior hypoglycemia is postulated to contribute to the development of hypoglycemia-associated autonomic failure (HAAF) in insulin-treated diabetic patients. This latter mode of elevating glycogen levels is termed "supercompensation." We tested whether brain glycogen supercompensation occurs in healthy, conscious mice after recovery from insulin-induced acute or recurrent hypoglycemia...
April 2011: Journal of Neuroscience Research
Gülin Oz, Anjali Kumar, Jyothi P Rao, Christopher T Kodl, Lisa Chow, Lynn E Eberly, Elizabeth R Seaquist
OBJECTIVE: We tested the hypotheses that human brain glycogen is mobilized during hypoglycemia and its content increases above normal levels ("supercompensates") after hypoglycemia. RESEARCH DESIGN AND METHODS: We utilized in vivo (13)C nuclear magnetic resonance spectroscopy in conjunction with intravenous infusions of [(13)C]glucose in healthy volunteers to measure brain glycogen metabolism during and after euglycemic and hypoglycemic clamps. RESULTS: After an overnight intravenous infusion of 99% enriched [1-(13)C]glucose to prelabel glycogen, the rate of label wash-out from [1-(13)C]glycogen was higher (0...
September 2009: Diabetes
A B Walls, C M Heimbürger, S D Bouman, A Schousboe, H S Waagepetersen
The significance and functional roles of glycogen shunt activity in the brain are largely unknown. It represents the fraction of metabolized glucose that passes through glycogen molecules prior to entering the glycolytic pathway. The present study was aimed at elucidating this pathway in cultured astrocytes from mouse exposed to agents such as a high [K+], D-aspartate and norepinephrine (NE) known to affect energy metabolism in response to neurotransmission. Glycogen shunt activity was assessed employing [1,6-13C]glucose, and the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) to block glycogen degradation...
January 12, 2009: Neuroscience
Raimund I Herzog, Owen Chan, Sunkyung Yu, James Dziura, Ewan C McNay, Robert S Sherwin
Our objective was to evaluate whether excessive brain glycogen deposition might follow episodes of acute hypoglycemia (AH) and thus play a role in the hypoglycemia-associated autonomic failure seen in diabetic patients receiving intensive insulin treatment. We determined brain glucose and glycogen recovery kinetics after AH and recurrent hypoglycemia (RH), an established animal model of counterregulatory failure. A single bout of insulin-induced AH or RH for 3 consecutive days was used to deplete brain glucose and glycogen stores in rats...
April 2008: Endocrinology
Anna Robins
The Ironman triathlon is an ultraendurance event that requires specific training and individually tailored nutritional practice. Carbohydrate depletion and dehydration are likely causes of fatigue, yet hyponatremia has been highlighted as a major concern during such events. As a consequence, triathletes are recommended to evaluate fluid losses during practice sessions and develop personal fluid replacement programs to ensure fluid balance. With regard to dietary preparation there are new methods of glycogen supercompensation, recommendations for improving fat oxidation while maintaining endogenous glycogen stores, and evidence aligned to the benefit of consuming combined carbohydrate intake during the race to increase exogenous carbohydrate oxidation rates...
July 2007: Current Sports Medicine Reports
Mads K Dalsgaard, Niels H Secher
Central fatigue refers to circumstances in which strength appears to be limited by the ability of the central nervous system to recruit motoneurons. Central fatigue manifests when the effort to contract skeletal muscles is intense and, thus, is aggravated when exercise is performed under stress, whereas it becomes attenuated following training. Central fatigue has not been explained, but the cerebral metabolic response to intense exercise, as to other modalities of cerebral activation, is a reduction in its "metabolic ratio" (MR), i...
November 15, 2007: Journal of Neuroscience Research
Thierry Alquier, Junji Kawashima, Youki Tsuji, Barbara B Kahn
Antecedent hypoglycemia blunts counterregulatory responses that normally restore glycemia, a phenomenon known as hypoglycemia-associated autonomic failure (HAAF). The mechanisms leading to impaired counterregulatory responses are largely unknown. Hypothalamic AMP-activated protein kinase (AMPK) acts as a glucose sensor. To determine whether failure to activate AMPK could be involved in the etiology of HAAF, we developed a model of HAAF using repetitive intracerebroventricular (icv) injection of 2-deoxy-D-glucose (2DG) resulting in transient neuroglucopenia in normal rats...
March 2007: Endocrinology
David A Arnall, Arnold G Nelson, Jack Quigley, Stephen Lex, Tom Dehart, Peggy Fortune
Research data indicates a persistence of elevated muscle glycogen concentration 3 days post-supercompensation in resting athletes. This study expands our earlier findings by determining whether muscle glycogen remains elevated 3, 5, or 7 days post-supercompensation. Seventeen trained male cyclists underwent one bout of exhaustive exercise to deplete muscle glycogen. This was followed by a 3-day consumption of a high carbohydrate/low protein/low fat diet (85:08:07%). Three post-loading phases followed with subjects randomly assigned to either a 3-day, 5-day, or 7-day post-loading maintenance diet of 60% carbohydrate and limited physical activity...
February 2007: European Journal of Applied Physiology
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