BACKGROUND & AIMS: Carbohydrate is considered one of the main ergogenic resources available for athletes and physically active people. Adequate daily carbohydrate intake before, during and after exercise can ensure the maintenance of glycogen stores in the body and, thus, optimize the athlete's endurance performance. Thus, this study aimed to examine the effects of carbohydrate supplementation on endurance performance, specifically runners and cyclists. METHODS: This systematic review was carried out by searching for scientific articles indexed in the MEDLINE/PubMed, SCIELO, Web of Science, Scopus and Embase databases. Studies were selected considering the following criteria: (I) Randomized clinical trials (RCTs), without a defined time frame, published in any language
(II) With healthy runners and cyclists without age limit
(III) That addressed carbohydrate supplementation in endurance athletes
(IV) And pointed out the effects of carbohydrate consumption pre, during and/or post-workout. Thirteen RCT were included in this systematic review. RESULTS: Carbohydrate intake favors the recovery of glycogen stores between exercise sessions, allowing the maintenance and stimulation of intensity. Therefore, the use of carbohydrate supplementation has a beneficial effect on endurance performance and increases the exercise capacity of endurance athletes in various scenarios. CONCLUSION: This review highlights the importance of appropriate and personalized supplementation strategies, considering several factors to optimize endurance performance.