Research
Macro partitioning
Co-ingesting protein with carbohydrate during endurance exercise does not improve performance or glycogen resynthesis when carbohydrate recommendations are met.
Do not rely on adding protein to your in-exercise nutrition for performance or glycogen storage. Stick to recommended carbohydrate intakes. Save protein for post-exercise recovery.
GoodRefutesHIGH confidence
there remains no compelling evidence that co-ingesting protein with carbohydrate before or during endurance exercise confers any performance advantage, nor facilitates the resynthesis of liver or muscle glycogen stores during recovery, at least when carbohydrate recommendations are met.
Why this rating
Based on multiple metabolic studies comparing CHO vs CHO+Protein.
Source
Protein Nutrition for Endurance Athletes: A Metabolic Focus on Promoting Recovery and Training Adaptation
Oliver C. Witard et al. · Sports Medicine · 2025
DOI 10.1007/s40279-025-02203-8
narrative_reviewCited 19×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Endurance athletes require a daily protein intake of approximately 1.8 g/kg body mass per day, which may increase to >2.0 g/kg/day during carbohydrate-restricted training or on rest days.Good
- Post-exercise protein ingestion stimulates myofibrillar muscle protein synthesis (MPS) but has little to no effect on mitochondrial MPS rates during recovery from endurance exercise.Moderate
Related findings · Macro partitioning
- Total daily protein intake of 1.6 g/kg/day is sufficient for maximizing resistance training-induced muscle gains, with an upper confidence interval of 2.2 g/kg/day.Strong
- Resistance exercise training combined with sufficient dietary protein intake acts synergistically to maximize skeletal muscle hypertrophy, with protein intake saturating around 1.6 g/kg/day for general populations and potentially requiring 2.0-2.2 g/kg/day for resistance-trained individuals.Strong
- Trans fats should be completely eliminated from the diet, as they increase LDL cholesterol, decrease HDL cholesterol, and are directly associated with increased coronary risk.Strong
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