More than a store: regulatory roles for glycogen in skeletal muscle adaptation to exercise.

@article{Philp2012MoreTA,
  title={More than a store: regulatory roles for glycogen in skeletal muscle adaptation to exercise.},
  author={Andrew Philp and Mark Hargreaves and Keith Baar},
  journal={American journal of physiology. Endocrinology and metabolism},
  year={2012},
  volume={302 11},
  pages={
          E1343-51
        }
}
The glycogen content of muscle determines not only our capacity for exercise but also the signaling events that occur in response to exercise. The result of the shift in signaling is that frequent training in a low-glycogen state results in improved fat oxidation during steady-state submaximal exercise. This review will discuss how the amount or localization of glycogen particles can directly or indirectly result in this differential response to training. The key direct effect discussed is… 

Figures and Tables from this paper

Regulation of Muscle Glycogen Metabolism during Exercise: Implications for Endurance Performance and Training Adaptations

An overview of the regulatory control of CHO metabolism during exercise is presented (with a specific emphasis on muscle glycogen utilization) in order to discuss the effects of both high and low CHO availability on modulating exercise performance and training adaptations, respectively.

Diurnal variations in muscle and liver glycogen differ depending on the timing of exercise

Diurnal variations in liver and muscle glycogen compared to baseline levels were significantly different depending on the timing of exercise, which is useful for future research on energy metabolism.

The role of exercise and hypoxia on glucose transport and regulation.

The importance of muscle glycogen depletion and the key glucoregulatory hormones will be discussed, and the potential for systemic hypoxia to enhance the effects of exercise on glucose regulation is discussed.

Carbohydrate Metabolism During Exercise

Exercise Timing Matters for Glycogen Metabolism and Accumulated Fat Oxidation over 24 h

It is suggested that postabsorptive exercise alone effectively increases 24 h fat oxidation, and the variations in muscle and liver glycogen caused by post absorptionptive or postprandial exercise were consistent with indirect calorimetry data.

Post-Exercise Muscle Glycogen Resynthesis in Humans 2

Dietary strategies that can enhance glycogen synthesis from sub-optimal amounts of CHO or energy intake are of practical interest to many athletes; in this scenario, the co-ingestion of protein with CHO can assist glycogen storage.

Skeletal Muscle Glycogen Content at Rest and During Endurance Exercise in Humans: A Meta-Analysis

The effects of fitness, acute dietary carbohydrate (CHO) availability and other factors on muscle glycogen concentration at rest and during exercise of different durations and intensities were meta-analyse.

A century of exercise physiology: key concepts in regulation of glycogen metabolism in skeletal muscle

  • A. Katz
  • Biology
    European Journal of Applied Physiology
  • 2022
Despite the extensive amount of knowledge accrued during the past 100 years, several critical questions remain regarding the regulation of glycogen metabolism and its role in living muscle.

Exercise-induced cell signalling responses of human skeletal muscle : the effects of reduced carbohydrate availability

The primary aim of this thesis is to characterise the skeletal muscle cell signalling responses thought to regulate mitochondrial biogenesis following an acute bout of high-intensity interval exercise and moderate- intensity continuous exercise.

Chronic post-exercise lactate administration with endurance training increases glycogen concentration and monocarboxylate transporter 1 protein in mouse white muscle.

The results suggest that chronic lactate administration after exercise increases MCT1 protein expression, which can be involved in the regulation of the observed increase in muscle glycogen storage after exercise training.
...

References

SHOWING 1-10 OF 154 REFERENCES

Altering endogenous carbohydrate availability to support training adaptations.

Although 'training low' may increase cellular markers associated with training and enhance functions such as fat oxidation at sub- maximal exercise intensities, how this translates to performance is unclear.

Human skeletal muscle glycogen utilization in exhaustive exercise: role of subcellular localization and fibre type

It is shown that after prolonged exhaustive exercise the depletion of glycogen stores is dependent on its localization within the muscle cells, and consideration of distinct localizations within the muscles may advance understanding of how and why low muscle glycogen content impairs muscle function.

Novel Aspects of Skeletal Muscle Glycogen and Its Regulation During Rest and Exercise

Although it is often viewed as a homogenous substrate, glycogen is comprised of individual granules or ‘glycosomes’ that vary in their composition, subcellular localization, and metabolism, which result in additional levels of regulation allowing granules to be regulated individually or regionally within the cell during both rest and exercise.

A study of the glycogen metabolism during exercise in man.

The glycogen content of the quadriceps femoris muscle was determined in needle biopsy specimens taken from normal subjects in connexion with muscular work and the carbohydrate metabolism of the liver was studied before and during periods of exercise.

Muscle Glycogen Synthesis after Exercise : an Enhancing Factor localized to the Muscle Cells in Man

Goldstein1 has shown that a humoral factor, which decreases the blood glucose concentration, is released during exercise and it is known that the insulin requirement decreases in diabetic subjects during exercise.

Effect of muscle glycogen on glucose, lactate and amino acid metabolism during exercise and recovery in human subjects

The results suggest that the observed differences in metabolism between the low‐ Glycogen and the normal‐glycogen leg are induced by the glycogen level per se, since the legs received the same arterial supply of hormones and substrates.

Reduced glycogen availability is associated with an elevation in HSP72 in contracting human skeletal muscle

It is demonstrated that while acute, concentric exercise is capable of increasing HSP72 in human skeletal muscle, it does so only when glycogen is reduced to relatively low levels, suggesting that skeletal muscle is impermeable to H SP72.

Muscle glycogen content and glucose uptake during exercise in humans: influence of prior exercise and dietary manipulation

The data suggest that pre‐exercise glycogen content may influence glucose uptake during subsequent exercise, however, this is only the case when delivery of substrates and hormones remains constant.

Increased intramuscular lipid storage in the insulin-resistant and endurance-trained state

The reported correlation between IMTG content and insulin resistance does not represent a functional relationship, as it is strongly influenced by training status and/or habitual physical activity, and it can be argued that the ratio between IM TG content and muscle oxidative capacity represents a more accurate marker of insulin resistance.

Carbohydrate ingestion does not alter skeletal muscle AMPK signaling during exercise in humans.

Findings indicate that AMPK activation in skeletal muscle during exercise in humans is not sensitive to changes in plasma glucose levels in the normal range, and the rise in plasma epinephrine levels in response to exercise was greatly suppressed by CHO ingestion without altering AMPK signaling.
...