Macro partitioning
Ingesting 10–12.5 g carbohydrate per kg body mass per day for 1–7 days prior to competition increases muscle glycogen to 170–180 mmol/kg wet mass and enhances endurance performance in events lasting 90 minutes or more.
If you are competing in an event longer than 90 minutes, start eating 10–12.5 grams of carbohydrates per kilogram of your body weight daily for 1–7 days before the race. You do not need to do extreme exercise during this time; light activity is fine. This maximizes your muscle glycogen stores, which is the primary fuel for long endurance efforts.
Increased dietary carbohydrate intake in the days before competition increases muscle glycogen levels and enhances exercise performance in endurance events lasting 90 min or more.
Why this rating
Supported by multiple classic studies (Bergstrom, Sherman, Coyle) and consistent findings across decades.
Source
Pre-exercise carbohydrate and fat ingestion: effects on metabolism and performance
Mark Hargreaves et al. · Journal of Sports Sciences · 2003
DOI 10.1080/0264041031000140536
More from this paper
- Ingesting 200–300 g of carbohydrate 3–4 hours before exercise enhances endurance performance by increasing muscle and liver glycogen and maintaining blood glucose, with effects persisting for up to 6 hours.Good
- Ingesting carbohydrate 30–60 minutes before exercise does not impair performance and may enhance it, despite causing metabolic shifts like increased carbohydrate oxidation and inhibited fat oxidation.Good
- Increasing fat availability before exercise (via high-fat diet or fat infusion) reduces carbohydrate utilization but does not improve exercise performance.Good
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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