Purpose: The paper aims to describe the role and effects of carnosine and β-alanine on exercise. Design/methodology/approach: The review includes the most updated studies found in Pub-Med all of which are in relation to carnosine and β-alanine on exercise performance. Findings: The use of β-alanine in recent research has shown to increase muscle carnosine concentrations in as short as two weeks, with increasing levels with longer supplementation periods. Although there is strong support that β-alanine supplementation during training possesses ergogenic value, the specific mechanism of action and ergogenic value remains to be fully examined. Originality/value: The paper gives information to nutritionists, clinical dietitians and sports nutritionists on the newest data about the role and effects of carnosine and β-alanine on exercise performance.