Valine
The third BCAA. Valine is one of the three branched-chain amino acids, alongside leucine and isoleucine. While less researched individually, valine plays important roles in muscle maintenance, energy production, and interestingly, mental alertness—by competing with tryptophan for brain entry, it can affect serotonin levels and fatigue perception.
Key Functions
Muscle Maintenance
Provides nitrogen for muscle tissue. Helps prevent muscle breakdown during exercise or fasting.
Energy Production
Metabolized in muscle for ATP. Can serve as direct fuel during prolonged exercise.
Mental Alertness
Competes with tryptophan for brain entry. May reduce exercise-induced mental fatigue.
Nervous System
Important for proper nerve function and coordination. May help with tremors.
Tissue Repair
Supports wound healing and tissue regeneration. Important post-injury or surgery.
Blood Sugar
May help maintain stable blood glucose levels. Less potent than isoleucine for this.
The Tryptophan Connection
BCAAs (including valine) and tryptophan compete for the same transporter across the blood-brain barrier:
Less serotonin made. May reduce perception of fatigue during exercise. Can feel more alert.
More serotonin made. May feel sleepy or fatigued. This is why carb-heavy meals cause drowsiness.
Food Sources
Animal Sources
Meat, poultry, fish, eggs, dairy. All animal proteins are complete with good valine content.
Plant Sources
Soy, beans, lentils, peanuts, mushrooms. Combine varied plant proteins for complete profile.