Research

Mixed

Short-term fat adaptation (5-6 days of high-fat diet followed by carbohydrate restoration) increases fat oxidation and spares muscle glycogen during submaximal exercise but does not improve performance in prolonged endurance events.

Do not use a high-fat diet followed by carb loading to try to improve your race time. While this strategy successfully teaches your body to burn more fat and save glycogen, it does not make you faster or help you finish endurance events sooner. Stick to standard carbohydrate strategies for performance.

GoodRefutesHIGH confidence
fat-adaptation/CHO restoration strategies do not provide clear benefits to the performance of prolonged endurance exercise.
Louise M. Burke et al. · Medicine & Science in Sports & Exercise · 2002

Why this rating

Based on a review of multiple controlled studies (Tables 1-3) with consistent findings on metabolism, though performance results are mixed/null.

Source

Effects of short-term fat adaptation on metabolism and performance of prolonged exercise

Louise M. Burke et al. · Medicine & Science in Sports & Exercise · 2002

DOI 10.1097/00005768-200209000-00015

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DOI resolved against Crossref · corpus check 2026-06-10

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