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

Abstract

Non‐technical summary During prolonged high‐intensity exercise the main fuel for muscular work is glycogen, the storage form of glucose in skeletal muscle. The role of muscle glycogen in muscle function is best demonstrated by the inability to sustain prolonged high‐intensity exercise when the glycogen stores are depleted. Despite this knowledge, the reason why muscle function is depressed when glycogen levels are low is still not known. We show that after prolonged exhaustive exercise the depletion of glycogen stores is dependent on its localization within the muscle cells. These results show that consideration of distinct localizations within the muscle cells may advance understanding of how and why low muscle glycogen content impairs muscle function.