You may or may not have noticed that citrulline is not always written the same on supplement labels. Sometimes, you will see 'L-Citrulline', other times 'Citrulline Malate'. These two ingredients are not the same thing. So, how do the two compare and which should you look out for?
L-Citrulline is an amino acid which is sometimes combined with another acid, malic acid, for use in pre-workouts. Citrulline Malate is commonly a 1:1 or 2:1 ratio of citrulline to malic acid, so you will often need double the dose for the same amount of citrulline than when 'L-Citrulline' is the ingredient of choice.
How it works
L-Citrulline is a non-essential amino acid found naturally in watermelon. When consumed, is converted to arginine which the body uses to produce nitric oxide. Nitric Oxide causes vasodilation, for better blood flow during workouts. This means a better pump, better delivery of nutrients to the muscles, and faster removal of waste. It might appear that supplementing arginine from the off might be more efficient, but this is actually not the case. Studies have shown citrulline to be more effective at raising blood arginine levels than taking arginine itself.
Malate is an important intermediate in the Kreb's Cycle, which is important for the synthesis of ATP. Shortages of malic acid have been associated with chronic fatigue from the reduction in cellular energy. Along with its own benefits, it is thought to increase the absorption and bioavailabilty of citrulline.
L-Citrulline has been studied well in an aerobic exercise setting. One cycle trial found improved tolerance to severe-intensity exercise and increased total amount of work completed in the exercise performance test with supplementation.
Citrulline Malate,on the other hand, has been more tied to anaerobic performance. Supplementation resulted in significant reduction in fatigue, a 34% increase in the rate of oxidative ATP production during exercise and a 20% increase in the rate of phosphocreatine recovery after exercise in one 2002 study. Another study on resistance trained men, found a significant increase in reps performed and a significant 40% decrease in post training soreness
Which is better?
There aren't currently any major studies comparing the efficacy of the two head to head. Both seem to improve performance when tested independently. however, there is some discussion that Citrulline Malate might be the more appropriate choice for strength athletes, whereas L-Citrulline may be more applicable to endurance work.
Remember that Citrulline Malate is Citrulline cut with another amino acid, so look for a higher dosage compared to L-Citrulline on supplement labels for the best effects. Gram for gram, citrulline malate is often cheaper for companies to get a hold of, don't be caught out!
In conclusion... both can yield great performance benefits. Generally, we would recommend a product well dosed with citrulline malate over one with L-Citrulline, but you might want to try both and make up your own mind!
Dosage (per day):
6-8g Citrulline Malate
3-5g of L-citrulline
Stacks well with: creatine, beta-alanine, caffeine.
Total War provides 6g Citrulline Malate at the preferred higher ratio