REVIEW Open Access International society of sports nutrition position stand: nutrient timing Chad M. Kerksick 1 , Shawn Arent 2 , Brad J. Schoenfeld 3 , Jeffrey R. Stout 4 , Bill Campbell 5 , Colin D. Wilborn 6 , Lem Taylor 6 , Doug Kalman 7 , Abbie E. Smith-Ryan 8 , Richard B. Kreider 9 , Darryn Willoughby 10 , Paul J. Arciero 11 , Trisha A. VanDusseldorp 12 , Michael J. Ormsbee 13,14 , Robert Wildman 15 , Mike Greenwood 9 , Tim N. Ziegenfuss 16 , Alan A. Aragon 17 and Jose Antonio 18* Abstract Position statement: The International Society of Sports Nutrition (ISSN) provides an objective and critical review regarding the timing of macronutrients in reference to healthy, exercising adults and in particular highly trained individuals on exercise performance and body composition. The following points summarize the position of the ISSN: 1. Nutrient timing incorporates the use of methodical planning and eating of whole foods, fortified foods and dietary supplements. The timing of energy intake and the ratio of certain ingested macronutrients may enhance recovery and tissue repair, augment muscle protein synthesis (MPS), and improve mood states following high-volume or intense exercise. 2. Endogenous glycogen stores are maximized by following a high-carbohydrate diet (8–12 g of carbohydrate/kg/ day [g/kg/day]); moreover, these stores are depleted most by high volume exercise. 3. If rapid restoration of glycogen is required (< 4 h of recovery time) then the following strategies should be considered: a) aggressive carbohydrate refeeding (1.2 g/kg/h) with a preference towards carbohydrate sources that have a high (> 70) glycemic index b) the addition of caffeine (3–8 mg/kg) c) combining carbohydrates (0.8 g/kg/h) with protein (0.2–0.4 g/kg/h) 4. Extended (> 60 min) bouts of high intensity (> 70% VO 2 max) exercise challenge fuel supply and fluid regulation, thus carbohydrate should be consumed at a rate of ~30–60 g of carbohydrate/h in a 6–8% carbohydrate- electrolyte solution (6–12 fluid ounces) every 10–15 min throughout the entire exercise bout, particularly in those exercise bouts that span beyond 70 min. When carbohydrate delivery is inadequate, adding protein may help increase performance, ameliorate muscle damage, promote euglycemia and facilitate glycogen re-synthesis. 5. Carbohydrate ingestion throughout resistance exercise (e.g., 3–6 sets of 8–12 repetition maximum [RM] using multiple exercises targeting all major muscle groups) has been shown to promote euglycemia and higher glycogen stores. Consuming carbohydrate solely or in combination with protein during resistance exercise increases muscle glycogen stores, ameliorates muscle damage, and facilitates greater acute and chronic training adaptations. 6. Meeting the total daily intake of protein, preferably with evenly spaced protein feedings (approximately every 3 h during the day), should be viewed as a primary area of emphasis for exercising individuals. 7. Ingestion of essential amino acids (EAA; approximately 10 g)either in free form or as part of a protein bolus of approximately 20–40 g has been shown to maximally stimulate muscle protein synthesis (MPS). (Continued on next page) * Correspondence: ja839@nova.edu 18 Department of Health and Human Performance, Nova Southeastern University, Davie, FL, USA Full list of author information is available at the end of the article © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Kerksick et al. Journal of the International Society of Sports Nutrition (2017) 14:33 DOI 10.1186/s12970-017-0189-4