Lil Miss Fitness Freak

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Citrulline Malate…Fitness Friday 38

My friends! It’s March can you believe it? Seems like it was just New Years and now we are three months in already and Spring is in close reaching distance. Guess that is what the internship/Masters application process does to you…makes time fly.

Sidenote: I saw robins yesterday! I was partially excited (cuz spring sign!) but more so concerned because this was after a full on 20-25 degree reduction in temperature in one day. Please don’t be baby-makin yet birdies!


I’d be making that face too if it was 16 one day then I woke up to -10.In fact, I probably did look like that yesterday…

So coming back to another active ingredient in pre-workouts and also BCAA’s, I have always really wondered what this guy was good for. I mean, my coach said it was a good thing and it provided benefits, but apparently I was too busy to think about educating myself on why. I don’t like that….

I always stand for the whole ‘know what and why you are putting something into your body” philosophy and I obviously didn’t follow through with that on this one.

Time to take a scientific looky at it to settle my conscience.

Citrulline Malate

What is it?

Citrulline malate is the quite simply the combination of citrulline and malate. Pretty obvious eh? Citrulline is an important component of the urea cycle, which is where urea is formed from ammonia in the liver. This conversion is important because ammonia is actually toxic in the body if it builds up, while urea is a bit less harmful. Malate, on the other hand, is an intermediate in the  Kreb’s cycle, which is the cycle that releases energy from our macronutrients through oxidizing acetyl CoA.


What does it do?

It has been used in the past as an aid to decrease muscle fatigue and increase functionality. Many studies have shown these effects, whether human or animal (I will present some of the human ones below), in addition to speculating other benefits such as higher clearance of ammonia from the blood post exercise, a possible role in lactate metabolism and some effect on acid-base balance. The mechanism behind all of this remains unknown at this point however.

So, although it has shown benefits for athletic performance, particularly with respect to a more efficiently functioning muscle , we don’t have a strong conclusions as to how it is doing it.

So, below I will highlight a few studies and provide their findings, conclusions and hypotheses regarding a potential mode of action.

Bendahan et al (2002). “CM ingestion resulted in a significant reduction in the sensation of 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, indicating a larger contribution of oxidative ATP synthesis to energy production.” Their conclusion? The mechanism of CM’s action that reduces weakness and fatigue could be that it increases aerobic ATP production through providing more of the intermediates to replenish those that were lost more quickly than if you weren’t supplementing. [6g CM used]

Perez-Guisado et al (2010). Their study found that males athletes supplemented with CM saw more than 50% increases in the number of repetitions for barbell bench and a significant decrease in muscle fatigue 24 and 48 hours following the study’s training regime in a double blind, within subject study. In their research, they stated that studies have begin to speculate a role of ammonia in in “blocking cellular energy processes” and causing earlier fatigue. It has also been seen that it plays a role in NO reactions, which has been associated with recovery. Overall they concluded that the results from their study showed that one dose of CM helped with recovery and performance in high-intensity anaerobic activities with short rest times. [8g CM used]

Sureda et al (2010). They took subjects and had them cycle for ~137km with one difficult hill. All were given the same amount of food and fluid. They measured all variables (amino acids and all important exercise related metabolites) 3 hours prior to the race, 15 minutes following and 3 hours following. Overall, they found that the CM group showed a significant decease in the amount of the branched chain amino acids post race, which they said was due to the BCAAs being more effectively used for energy, than the control and higher arginine concentrations, which would contribute to many arginine derived metabolites such as nitrite, urea, creatinine and hormones like growth hormone that are beneficial for muscle growth and function. Finally, they also saw greater nitrogen availability in the CM group, which they stated could increase protein synthesis and protein concentrations in the muscle during exercise leading to better use of the amino acids (particularly the BCAAs). [6g CM used]

Overall, although I only highlighted a few interesting studies I found, I will say that the vast majority of studies I saw (which, I couldn’t have seen them all obviously…) showed significant improvements with its usage, so I have some confidence that it could provide a benefit to those who are looking (and can afford) to get a supplement that may actually do something useful and perhaps give a slight edge with recovery. Is it required to be a better athlete? Well no. Like all supplements, its not a magic powder that will give you huge energy bursts or make your recovery happen in 5 seconds. It is simply supplementing your routine and could provide some little bits of assistance and/or performance enhancements.

Happy Friday Friends!