International society of sports nutrition position stand: nutrient timing

Abstract

Position statementThe 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: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.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.If rapid restoration of glycogen is required (< 4 h of recovery time) then the following strategies should be considered:aggressive carbohydrate refeeding (1.2 g/kg/h) with a preference towards carbohydrate sources that have a high (> 70) glycemic indexthe addition of caffeine (3–8 mg/kg)combining carbohydrates (0.8 g/kg/h) with protein (0.2–0.4 g/kg/h) Extended (> 60 min) bouts of high intensity (> 70% VO2max) 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.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.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.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).Pre- and/or post-exercise nutritional interventions (carbohydrate + protein or protein alone) may operate as an effective strategy to support increases in strength and improvements in body composition. However, the size and timing of a pre-exercise meal may impact the extent to which post-exercise protein feeding is required.Post-exercise ingestion (immediately to 2-h post) of high-quality protein sources stimulates robust increases in MPS....

Macronutrient Intake for Physical Activity

“…It may sound like simple carbohydrates are vastly inferior to complex, but a mix of carbohydrate types is benefi cial for supplying athletes with energy. While the majority of the sedentary population should cut back and even avoid sugar-sweetened beverages, the athletic population has better use of shortterm simple sugar-containing beverages to enhance training adaptations and exercise performance during competition [ 13 ]. With that said, athlete should consume simple sugars before, during, and after exercise training (this will be further discussed in the nutrient timing section).…”

<p>Whey protein supplementation and muscle mass: current perspectives</p>

“…), whey protein supplements possess a higher digestibility, leading to a rapid rise in the postprandial aminoacidemia. Even though muscles remain sensitized to protein ingestion for at least 24 hrs following exercises, 76 from a practical viewpoint some athletes may struggle, particularly those with high body masses, to consume enough protein to meet their required daily needs (>1.6 g/kg). Therefore, the pragmatic recommendation is for an athlete to eat as soon as possible after a workout, ingesting >0.24 to~0.4 g/kg of high-quality protein sources, eg, WPI, WPC or WPH.…”

Efectos de los suplementos de proteína y aminoácidos de cadena ramificada en entrenamiento de fuerza: revisión bibliográfica

“…Respuesta anabólica en la recuperación muscular: Después del ejercicio, la ingesta de diferentes tipos de suplementos de proteína aumenta las tasas de síntesis de proteí-nas musculares (SPM), estimula el crecimiento del balance proteico neto y facilita la respuesta adaptativa del músculo al entrenamiento prolongado 57,58 . También se ha observado que la ingesta de suplementos de proteína, antes y durante el ejercicio prolongado, puede ser una estrategia eficaz para facilitar la SPM y mejorar la respuesta adaptativa del músculo esquelético 57,59 .…”

“…También se ha observado que la ingesta de suplementos de proteína, antes y durante el ejercicio prolongado, puede ser una estrategia eficaz para facilitar la SPM y mejorar la respuesta adaptativa del músculo esquelético 57,59 . Es a partir de aquí que se intenta dar respuesta a toda una serie de proteínas y enzimas que intervienen en la respuesta anabólica del músculo y que tienen una estrecha relación entre ellas.…”