International society of sports nutrition position stand: nutrient timing.
Level 5 - mechanism / opinion, no new human data
Narrative review and expert consensus position stand with no systematic search methodology
PubMed 28919842 · doi:10.1186/s12970-017-0189-4
What was done
The International Society of Sports Nutrition (ISSN) conducted a critical narrative review of existing literature to establish an official position stand regarding macronutrient timing for exercise performance, recovery, and body composition in healthy exercising adults and highly trained individuals.
What was found
The position stand provides specific nutrient intake guidelines: - Glycogen stores are maximized with a baseline high-carbohydrate diet (8-12 g/kg/day). - Rapid glycogen resynthesis (<4 h recovery) requires 1.2 g/kg/h of high glycemic index carbohydrates, adding 3-8 mg/kg caffeine, or combining 0.8 g/kg/h carbohydrate with 0.2-0.4 g/kg/h protein. - Extended exercise (>60 min at >70% VO2 max) requires 30-60 g carbohydrate/h in a 6-8% solution every 10-15 min. - Maximal muscle protein synthesis (MPS) occurs with ingestion of ~10 g essential amino acids or 20-40 g high-quality protein (0.25-0.40 g/kg/dose) spaced every 3-4 h, including pre- or post-exercise (0-2 h post). - Pre-sleep casein protein ingestion (~30-40 g) increases overnight MPS and metabolic rate without affecting lipolysis.
Why it matters
This position stand synthesizes practical macronutrient timing protocols for athletes to optimize recovery, muscle protein synthesis, and exercise adaptations.
Limits
The paper is a narrative position stand rather than a systematic review or meta-analysis, with no pooled effect sizes, risk-of-bias evaluations, or total participant counts reported in the abstract. Recommendations are primarily tailored to athletic cohorts and may not generalize to sedentary populations.
Cited by
- context The macronutrient composition of a meal consumed immediately prior to a resistance training workout is unlikely to be used as fuel during that workout.