input: [Recommendation] Make fat work for you [Why] 
output: Some athletes have found success following a high-fat diet for a number of days and then briefly eating a high-carbohydrate diet prior to an endurance event. Some athletes have speculated that consuming a high-fat diet for two or more weeks prior to endurance competition might cause the body to shift its fuel utilization toward more abundant fat stores ("fat adaptation").39 However, neither short-term nor long-term use of high-fat diets has been found to improve endurance performance compared with high-carbohydrate diets, and may even be detrimental due to depletion of glycogen stores.40 , 41 Following a high-fat diet with at least 24 hours of high carbohydrate intake has been suggested as a way to achieve fat adaptation while restoring glycogen levels before endurance competition.42 , 43 While this concept is supported by physiological studies on athletes, no actual performance enhancement was shown when athletes were tested in competitive situations after a five- to six-day high-fat diet followed by 24 hours of high carbohydrate intake.44 , 45 , 46 However, one controlled study found a small, significant benefit of ten days of high fat intake followed by three days of high carbohydrate intake.47