Muscle cells break down their protein when their blood glucose levels fall, which happens during fasting or periods of intense exercise.
Glucogenic and ketogenic amino acids are classified according to the metabolic pathways they enter after being broken down.
Glucogenic amino acids can be converted into intermediates that feed the gluconeogenesis metabolic pathway, which produces glucose.
As previously stated, because they can be transformed into glucose via a variety of metabolic pathways, the majority of amino acids (apart from leucine and lysine) are regarded as glucogenic.
These substances undergo a process called ketogenesis that produces ketone bodies like acetoacetate, beta-hydroxybutyrate, and acetone.