Research on Skeletal Muscle Glycogen Storage Kinetics, Supercompensation Mechanisms, and Periodized Nutritional Supplementation Strategies in Endurance Exercise

In endurance exercise, skeletal muscle glycogen serves as a principal carbohydrate source, especially during high-intensity exercise. The storage, utilization, and replenishment of glycogen in muscles after exercise affect the quality of training, the recovery process, and endurance performance. This paper reviews the dynamic changes in the glycogen status of skeletal muscle and its related regulatory mechanisms, and clarifies how different glycogen levels and carbohydrate availability affect athletes' adaptation to endurance training and their performance. Moreover, it also examines how carbohydrate periodization regulates glycogen availability, influences training adaptation, and preserves exercise performance. In this context, low muscle glycogen may limit high-intensity, high-volume training, while adequate post-exercise carbohydrate intake promotes glycogen resynthesis and may induce glycogen supercompensation. Meanwhile, although low-glycogen training may upregulate signaling proteins involved in cellular adaptation, lipid oxidation, and mitochondrial biogenesis, these metabolic adaptations have not consistently improved competitive performance. Thus, during endurance training, carbohydrate intake should be periodized according to exercise intensity and duration, recovery demands, and individual needs rather than maintained at consistently high or low levels, to balance training quality, metabolic adaptation, and performance.