If you have followed the supplement industry as long as I have then you will have seen a number of supplements which were hyped at the time end up consigned to the rubbish bin of history. Few people today still talk about or use OKG, Bee Pollen, AKG, Chromium Picolinate, Vanadyl Sulfate or Ginseng to name a few well known supplements which, at one time or another, appeared on virtually all supplement store shelves. The reason for their eventual disappearance is the lack of real world or clinically based results in these supplements for producing positive outcomes for users.
A supplement which came out at roughly the same time as these was much less well known at the time but its continued research backed support from a multitude of studies has meant it is by now the most well known ergogenic of our time. I am of course talking about creatine.
Apart from creatine few supplements have met the dual requirement of evidence from real world users as well as studies. Partly this is due to the impossibility of conducting studies on nutrients such as testosterone boosters or prohormones due to university review boards being unlikely to publish them but also it is due to the fact that the cost of funding studies can be excessive.
A nutrient which has been around in the supplement industry for some time is Citrulline Malate which, while having many users praising its benefits, has not undergone much study on its effects on human performance. The increasing popularity of Citrulline deserves to be assessed scientifically and a recent study (1) in the Journal of Strength and Conditioning Research did just that.
Methods: The study investigated the ability of Citrulline Malate to boost performance and muscle recovery by taking a group of 41 men and randomising them to two groups following a double-blind, 2-period crossover design. The men performed two consecutive chest workouts comprising 8 sets per session. The subjects took 8 grams of Citrulline Malate in one of the two training sessions and a placebo in the other. Their resistance to fatigue was tested by measuring how many reps at 80% of their 1RM they could perform during their 8 sets of flat barbell bench presses.
Results: The number of reps performed showed a large increase from placebo to the CM treatment from the third set onwards. This increase was positively correlated with the number of sets such that by their final set the subjects were able to perform an average of 52.92% more repetitions. In short, the longer they trained the more the CM helped them. This was seen universally in all the subjects.
In addition to the increased number of reps performed, the CM supplemented group reported an average decrease of 40% in muscle soreness at 24 and 48 hours after the training session. The only negative reported was a feeling of stomach discomfort reported in 14.63% of the CM treated subjects.
Conclusion: The authors concluded that use of CM may be helpful for increasing athletic performance in high intensity activities and to lower post workout muscle soreness.
This study was only conducted recently and represents unambiguous support for the empirical results reported by many bodybuilders. The difference in results is very stark and lends support to the short term impact of dosing Citrulline Malate at a high level. Future research is warranted to see how the dosing of Citrulline Malate could improve body composition but given the performance gains in this study the suggestion that it can improve body composition should be taken seriously.
Further weight supporting the benefit of Citrulline Malate was provided by another study, conducted in 2010 (2) which divided trained cyclists into two groups, one given 6 grams of CM while the second was provided a placebo. The cyclists then raced over 137km and afterwards the measurements of the CM group showed higher levels of non-essential amino acids as well as an elevated level of growth hormone compared to placebo. If these results are allied to the acute performance enhancing benefits of Citrulline Malate then the argument in favour of supplementing Citrulline Malate becomes compelling.
One final thing to note is that the makers of Xtend have funded a study (3) which showed a clear advantage for supplementing their product during training compared to whey protein. Although we cannot distinguish to what extent this was due to the higher BCAA content of the Xtend supplemented group, it is certainly possible, in light of the peer-reviewed studies discussed, that part of the reason for the superiority of the Xtend group was the presence of Citrulline Malate in their product.
As we continue to see more research conducted into Citrulline Malate we should be able to ascertain more clearly exactly how beneficial it can be for users.
Products featuring Citrulline Malate
Author: Reggie Johal
1. Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010 May;24(5):1215-22.
2. Sureda A, et al. L-Citrulline-malate influence over branched chain amino acid utilization during exercise. Eur J Appl Physiol. 2010 Sep;110(2):341-51. Epub 2010 May 25.
3. Stoppani J, et al. Consuming a supplement containing branched-chain amino acids during a resistance-training program increases lean mass, muscle strength and fat loss. Proceedings of the Sixth International Society of Sports Nutrition (ISSN) Conference and Expo. June 2009
© 2012, Reggie Johal. All rights reserved.