Citrulline is the most important ingredient in a great preworkout supplement.
Yeah, I said it.
More useful than caffeine. More effective than creatine. More powerful than beta-alanine.
Sadly, it’s an ingredient which is usually just “thrown in” to pre workout formulas, often under-dosed and not truly maximized for performance benefits. But make no mistake about it, citrulline is the first thing I get my clients to look for when buying a new pre workout supplement.
Today, you will learn why.
If you are unsure what citrulline is, or what it actually does, then today’s article will give you a handy comprehensive guide.
WHAT IS CITRULLINE?
Commonly found in watermelon, citrulline is an amino acid.
When found in supplements, you’ll usually hear it referred to as citrulline malate. This is citrulline with a malic acid molecule attached to it (malate).
Occasionally, you’ll hear supplement companies attaching these molecules in a different ratio, such as two citrulline molecules to one malic acid molecule (“a 2:1 ratio”, as seen in Pre Jym).
Before we get stuck into the nitty gritty of today’s post, if you prefer your information in video form then checkout the video below, taken from my YouTube channel, where I discuss the main advantages to using citrulline malate before workouts:
- Increased muscular endurance
- Increased pump
- Increased levels of growth hormone
Pretty good, right?
This is why citrulline features prominently in my article How To Make Your Own Pre Workout.
If you are wondering how a simple substance like this can enhance your ability to train harder for longer, it doesn’t give you super powers. Instead, it’s all about lactic acid build-up.
Beta-alanine possesses the ability to temporarily buffer the onset of lactic acid. Citrulline, however, widens the blood vessels (more on this later) and enables your body to shuttle away lactic acid while you train. In doing so, you unlock the ability to train at your peak levels for longer than usual.
The inclusion of the malic acid molecule will also boost your body’s production of ATP, which enables you to recover slightly faster between sets.
Let’s look further into this, as it’s something I’m sure is exciting you as a weight lifting enthusiast.
A fabulous 2010 study published in the Journal of Strength and Conditioning Research looked at the effects of citrulline before a heavy chest workout. By providing one group of subjects with a preworkout serving of citrulline and another group with a placebo, the researchers wanted to see whether the citrulline would result in greater muscular endurance and recovery.
They found something quite startling…
From the third set of the workout, the group who used citrulline were able to perform an average of 1 more rep in every single set. (1)
One more rep on every single set?
Holy cow, Batman!
If you’re training as hard as Rocky in a Russian barn, this should have you feeling rather intrigued by the possibilities of using citrulline. After all, with continued supplementation, this could add some serious increases to your performance in the squat rack!
CITRULLINE VS ARGININE
If you know your pre workout supplements, you may recognize some of the training benefits touted above.
The substance you are thinking of is arginine.
Just like citrulline malate, arginine is another ingredient which is very commonly found in pre workout supplements and you are correct in noticing that it performs many of the same tasks.
After all, supplementing with arginine allows your body to increase nitric oxide levels, allowing your blood cells to widen and deliver more nutrients during training. (2)
Furthermore, due to the fact that our blood cells have widened to allow for greater delivery of nutrients, they are also receiving greater blood flow than usual. Seeing as blood is 50% water, this is why you get a great pump.
Increased blood flow and more nutrients delivered to your working muscles = greater training endurance!
It’s kinda like when Joey wore his Thanksgiving pants.
That’s the basis which every N.O. supplement on the market has been based upon since their introduction to the supplement world more than a decade ago. And back then, arginine was the king.
But times change…
We now know that arginine isn’t absorbed very well.
In fact, using citrulline malate is actually a superior way of getting the full benefits of arginine than using arginine directly!
Before your head explodes with that statement which doesn’t make any logical sense, allow me to explain.
An interesting 2002 study form Germany discovered that using citrulline caused higher blood levels of arginine than using arginine. (3)
This was then re-confirmed elsewhere, this time published in the British Journal of Pharmacology, where it was shown that citrulline is 50% more potent than arginine supplementation for raising blood levels of arginine. (4)
It all comes down to breakdown and transportation.
You see, once inside your body, arginine lasts about as long as a child abuser in gen pop.
Most of it will be destroyed in the liver and intestines (one study even suggested that as little as 1% makes it to the muscle cells) meaning we would need a f**king huge dose to achieve the kind of training results arginine is capable of. (5)
In comes citrulline, like the 1994 Arnold re-make of True Lies versus the 1991 original.
Bigger. Badder. Sexier.
Citrulline gets straight to work, bypassing the liver and intestines.
In a 2012 study published in Medicine and Sport Science, a team of Spanish researchers found that around 80% of citrulline actually makes it beyond the liver and intestines, into your kidneys, where it gets converted to arginine. (6)
Those numbers are much better, aren’t they?
That’s why your pre workout should include citrulline malate instead of arginine (although plenty of them still do use arginine, so keep your eye out).
It will also boost growth hormone levels, as mentioned in the bullet points above, but I’m not a fan of supplements which claim to boost GH levels. This is because it’s an over-hyped benefit. Temporarily boosting your levels of growth hormone while training simply does not give you any real edge when it comes to building more lean muscle. (7)
HOW MUCH CITRULLINE MALATE SHOULD YOUR PRE WORKOUT CONTAIN?
This is where most supplement companies get it dead wrong.
Manufacturers want to make the huge marketing claims on their packaging (i.e. increased pump, greater endurance) but they also want to keep production costs down.
This results in:
- use a proprietary blend
- use l-citrulline instead of citrulline malate
- using a combination of citrulline malate and arginine
By using a proprietary blend, a supplement manufacturer can basically tell you which ingredients are inside the product without disclosing any of the dosages. Meaning you know you’re getting some citrulline, but you have no idea how much.
They’ll claim this is to “protect their formula from rival companies looking to rip them off”, but in truth, this is a sign of a company who know they have under-dosed their formula and don’t want to admit it.
The fact that they’ve included the ingredient is enough to enable them to fill their tub with all those bold statements about the training benefits it offers, even if they’ve provided an under-dosed serving size which isn’t going to yield those benefits (it’s wrong, but that’s how the industry works).
Using the standard form of citrulline (known as l-citrulline) in place of citrulline malate is another option for keeping production costs down. But in doing so we lose some potency (remember, the malic acid molecule is important).
And I’ve already shown you why we do not need to use a combination of citrulline malate and arginine. Arginine shouldn’t be in there in the first place, unless you’ve mastered time travel and are reading this in 2004.
To get the full training benefits on offer (increased endurance, faster recovery, great pump) we need a dose of 6-8 grams of citrulline malate. Anything less, and you are being sold short.
SHOULD YOU START USING CITRULLINE MALATE?
I have one questions for you:
Do you perform endurance based training or a heavy weights-based routine?
Citrulline malate would be a great addition to your diet, whether as part of a pre workout or via a standalone product (it’s cheap enough).
It’s one of the few pre workout ingredients to be genuinely as useful as it claims to be, and it’s the first thing I get clients to look for when they are considering buying a new pre workout supplement.
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- Pérez-Guisado, J., et al. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010 May;24(5):1215-22. doi: 10.1519/JSC.0b013e3181cb28e0.
- Alvares, T. S., et al. Acute l-arginine supplementation increases muscle blood volume but not strength performance. Appl Physiol Nutr Metab. 2012 Feb;37(1):115-26.
- Kuhn, K. P., et al. Oral citrulline effectively elevates plasma arginine levels for 24 hours in normal volunteers. Circulation 2002; 106: II1–766S.
- Schwedhelm, E., et al. Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism. British Journal of Clinical Pharmacology, 65(1):51-9, 2008.
- Castillo, L., et al. Splanchnic metabolism of dietary arginine in relation to nitric oxide synthesis in normal adult man. Proc Natl Acad Sci USA 1993; 90: 193–7.
- Sureda, A., et al. Arginine and citrulline supplementation in sports and exercise: ergogenic nutrients? Med Sport Sci. 2012;59:18-28. doi: 10.1159/000341937. Epub 2012 Oct 15.
- West, D. W., et al. Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training. Eur J Appl Physiol. 2012 Jul;112(7):2693-702. doi: 10.1007/s00421-011-2246-z. Epub 2011 Nov 22.