There is an interesting review on Ketogenic diets and physical performance by Stephen D Phinney in Nutrition & Metabolism, an online journal published by BioMed Central.
The following three factors that can help us explain the paradox presented by studies showing superior performances with high carbohydrate diets:
- Adaptation period: a keto-adaptation period of 3-4 weeks (or more) is absolutely required.
- Sodium & potassium: the intake of sodium and potassium must be taken care of.
- Protein constraint: the optimal protein dose is approximately 1.5 g/kg/day, for athlete weights 60-80 kg this translates into total daily protein intake of 90-120 g.