Citrulline

What is Citrulline?

Citrulline is a non-essential amino acid that plays an important role in the body, especially for athletes and people who exercise regularly. It occurs naturally in certain foods, such as watermelon, and is known to increase levels of arginine and nitric oxide more effectively than arginine itself. Nitric oxide is a gas produced in the body that helps dilate blood vessels, improving blood flow and oxygen delivery to muscles during exercise.

How does it work in the body?

Citrulline is metabolised in the kidneys to arginine, which in turn is converted to nitric oxide. This means that citrulline can have a more prolonged effect on nitric oxide levels compared to direct intake of arginine. When blood vessels dilate, blood flow increases, which can lead to better performance and recovery after exercise.

Scientific benefits

Several studies have investigated the effects of citrulline on physical performance:

• Increased endurance: A study published in The Journal of Strength and Conditioning Research showed that citrulline supplementation can improve endurance and reduce fatigue during prolonged exercise.
• Improved pump: Another study in Nutrition demonstrated that citrulline increased blood flow to muscles, thereby enhancing the "pump" during resistance training.
• Recovery: Research has also shown that citrulline can reduce muscle soreness after exercise, which may lead to faster recovery.

These studies indicate that citrulline is a promising amino acid for those looking to maximise their training and improve performance.

Dosage and recommendations

The most common dosage of citrulline ranges between 6-8 grams per day to achieve maximum effect. It is recommended to take citrulline approximately 30-60 minutes before exercise for best results. There are also products with citrulline malate, which combines citrulline with malic acid, potentially providing additional endurance benefits.

Best sources and forms

Citrulline is available in various forms, including:

• Citrulline malate: A common form of citrulline often used in supplements to increase endurance and reduce fatigue.
• Pure citrulline: Also available in powder and capsule form, making it easy to dose.
• Natural sources: Watermelon is one of the best-known natural sources of citrulline, but it is also found in smaller amounts in other fruits and vegetables.

Side effects and warnings

Citrulline is generally considered safe for most people when taken at recommended doses. Some may experience mild side effects such as gastrointestinal discomfort or diarrhoea. It is important to consult a doctor before starting supplementation, especially if you have underlying health conditions or are taking other medications.

Frequently asked questions

What is the difference between citrulline and arginine?

Citrulline is converted to arginine in the body, which allows citrulline to raise nitric oxide levels more effectively than taking arginine directly.

Can citrulline help with recovery after exercise?

Yes, several studies have shown that citrulline can reduce muscle soreness and improve recovery after intense exercise.

Is citrulline safe to take daily?

Yes, citrulline is generally safe for most people, but it is always advisable to consult a doctor before starting new supplements.

How long does it take to see results from citrulline?

Results may vary, but many users report improved performance and pump during exercise within a few weeks of starting citrulline supplementation.

Can I get citrulline through diet?

Yes, citrulline occurs naturally in foods like watermelon, but supplements can provide a more concentrated dose for those looking to maximise their training effects.