If you want to perform well in sport, you need to be metabolically flexible. Metabolic flexibility is the body’s ability to use carbs at a high intensity when it needs to and switch over to fat when it doesn’t need to and go for much longer. Even endurance athletes go through high intensity periods throughout the race (finish line), so you still want to be able to use carbohydrates to provide quick energy. What you eat determines what fuel you will use during exercise. High-carb based diets and supplements bias your metabolism towards carbohydrate utilisation while simultaneously inhibiting fat mobilisation (“Metabolic inflexibility”). In order to sustain long periods of exercise under glycogen depletion, one must be keto-adapted (or fat-adapted) and metabolically flexible.
Possible benefits of a low carb/ketogenic diet in sport
- It is better for general health.
- A low carb diet has been shown to have anti-inflammatory effects and may produce less oxidative stress after exercise.
- Ability to use and mobilise fat to be utilised better during exercise
- Much less dependence on muscle glycogen as fuel
- Reduced need to reload carbohydrates after exercise
- Gut and immune functions improve
- Better body composition
- Increased power to weight ratio
- Potential improvement in central fatigue
- Improved risk of injury
- Improved recovery time
- Improved cognitive functioning
Keto-adaptation begins after 5 days (you may feel horrible during this period and performance decreases), peaks at 2-3 weeks, but may take 3-12 months to become fully fat adapted. More trained athletes will take longer to become fat adapted compared to recreational athletes.
