International Society of Sports Nutrition position stand: Nutrient timing

Previous research has demonstrated that the timed ingestion of carbohydrate, protein, and fat may significantly affect the adaptive response to exercise. The overall concept of macronutrient ratio planning for the diets of athletes is not addressed directly within this position stand, as there is no one recommendation which would apply to all individuals. However, the ISSN refers the reader to the latest Institute of Medicine Guidelines for Macronutrient intake as a source of more general information [1]. The purpose of this collective position statement is to highlight, summarize, and assess the current scientific literature, and to make scientific recommendations surrounding the timed ingestion of carbohydrates (CHO), protein (PRO), and fat. The enclosed recommendations are suitable for researchers, practitioners, coaches and athletes who may use nutrient timing as a means to achieve optimum health and performance goals. This position stand is divided into three primary sections: pre-exercise, during exercise and post-exercise. Each section concludes with several bullet points that highlight the key findings from each of the areas.Nutritional considerations prior to exercise have traditionally examined the administration of CHO to maximize endogenous glycogen stores [2-6] and maintain serum glucose levels during endurance exercise [4,7]. More recently, studies have begun to provide data supporting the contention that pre-exercise ingestion of CHO, amino acids, PRO, and creatine (Cr) prior to resistance training are effective modalities for enhancing exercise training adaptations [8-12] and decreasing exercise associated muscle damage [12,13].Body stores of glycogen are limited [7,14], and will last a few hours at best during moderate to high intensity levels (65 – 85% VO2max) of exercise [15]. As glycogen levels diminish, exercise intensity, and work output decrease [14], and frequently muscle tissue breakdown and immunosuppression ensues [16,17]. Due to the well-