The effects of glycaemic index and carbohydrate timing on improving athletic performance: A systematic review

Abstract

Background: Carbohydrates are classified by their action on blood glucose level which is also important for performance and energy availability according to the glycaemic index (GI). The meals with high GI energize us quickly, while the meals with low GI energize us slowly. Enhancing metabolic efficiency and muscle repair through key carbohydrate scheduling enhances glycogen storage, recovery, and hence endurance for better sports performance. Objective: This systematic review examines the effects of GI and carbohydrate timing on athletic performance across different sports disciplines. It aims to evaluate optimal carbohydrate intake strategies for endurance and high-intensity sports, comparing high and low GI consumption to enhance performance, recovery, and metabolic efficiency. Methods: The study conducted a systematic evaluation of the literature on the relationship between carbohydrate timing and glycaemic index in athletic performance, adhering to the PRISMA principles and the PICO framework. Using inclusion and exclusion criteria, a thorough search technique was used to find pertinent peer-reviewed research across databases. Results: The review found that GI and carbohydrate timing significantly influence athletic performance. High-GI carbs aid rapid energy replenishment post-exercise, while Low-GI options sustain endurance. Strategic carb intake before, during, and after exercise optimizes glycogen storage, enhances endurance, and accelerates recovery. Conclusion: The findings therefore highlight the importance of strategic carbohydrate timing and glycaemic index in enhancing athletic performance and speeding up recovery. Further research however should be directed at examining how carbohydrate consumption can be personalized for varying sports to help athletes achieve the greatest possible endurance and metabolic response.