Why do muscles prefer to oxidize glucose rather than fat and protein during exercie?

Muscles prefer to oxidize glucose during exercise primarily because it provides a quicker source of energy, as glucose can be rapidly broken down through glycolysis and the subsequent aerobic pathways. This quick energy release is essential during high-intensity activities where immediate fuel is needed. Additionally, glucose oxidation produces ATP more efficiently under anaerobic conditions compared to fat and protein, making it the preferred substrate for sustained muscle performance during vigorous exercise.