Creatine and Beta-Alanine Supplementation for Endurance Athletes: Ergogenic Aids for Reaching the Podium?

Endurance sports are characterized mainly by prolonged exercise demands. Although endurance performance is primarily supported by aerobic metabolism, anaerobic energy pathways, buffering capacity, neuromuscular resilience, and the ability to tolerate fatigue during decisive moments of a race are also relevant to competitive success. In this context, creatine and beta-alanine supplementation are two ergogenic strategies purported to enhance endurance performance. This review critically examines the physiological rationale and current evidence regarding creatine supplementation, beta-alanine supplementation, and their cosupplementation in endurance sports. The available literature suggests that beta-alanine may improve performance in exercise tasks performed in the aerobic-anaerobic transition zone, through increased skeletal muscle carnosine content and enhanced intracellular buffering capacity. Creatine supplementation may support endurance performance by increasing phosphocreatine availability, improving glycogen resynthesis and buffering capacity, attenuating exercise-induced inflammation and muscle damage, preserving fast-twitch muscle characteristics, and enhancing repeated sprint ability or late-race power output. However, evidence supporting improvements in classical markers of aerobic performance, such as VO₂max, lactate threshold, and time-to-exhaustion, remains inconsistent, and the available evidence has been derived from untrained or recreationally active individuals, limiting direct translation to highly trained endurance athletes. Therefore, the practical relevance of these supplements appears to depend on the athlete's training phase, event characteristics (e.g., weight-bearing or not), competitive goal, and performance level. Creatine and beta-alanine should not be viewed as universal ergogenic aids for endurance athletes, but rather as targeted nutritional strategies that may be particularly useful in race contexts where repeated high-intensity efforts, fatigue resistance, and decisive finishing actions influence performance.