Recent study reports remarkable muscle gains with CLA!
by Paul Cribb, B.H.Sci HMS
AST Director of Research
A very interesting study involving supplementation with Conjugated linoleic acid (CLA) was published last year. The results have been largely overlooked by the bodybuilding community however, they are very relevant to all strength athletes. This study is one of very few that have examined the effects of supplementation with CLA during a structured training program utilizing a large group of resistance-trained participants. The results obtained with CLA were quite simply, remarkable.
However, even more astonishing were the comments and conclusions made by the authors of the published manuscript. Let me give you a brief rundown of the protocol and results so you can see exactly what I mean.
The aim of this study was to examine the effects of CLA supplementation during a resistance training program on strength gains, body composition and markers of muscle catabolism (breakdown). In this study seventy-six resistance-trained participants were randomized to receive CLA (5 grams per day) or placebo for 7 weeks while training 3 days per week. Seventeen of the subjects then crossed over to the opposite group for an additional 7 weeks. All assessments were completed before, and then at 7 and 14 weeks.
The major findings from this study were that after the first 7 weeks the group given CLA demonstrated a significantly greater increase in lean mass (+1.4 vs +0.2 kg) and a greater reduction in fat mass (-0.8 vs +0.4 kg) compared to the placebo group. The group given CLA also showed a small but significant reduction in 3MH (a marker of muscle protein breakdown) compared to treatment with the placebo. Additionally, the males given CLA demonstrated significantly greater gains in bench press strength. In the crossover part of the study, CLA again had a significant impact on 3MH and muscle catabolism.
Based on the findings, supplementation with CLA during resistance training clearly resulted in a significantly better improvement in body composition. CLA also appeared to reduce the catabolic effect of training on muscle protein. This would explain the better gains in lean (muscle) mass from CLA.
However, in the published manuscript the authors conclusions were rather subdued to say the least. Within the first sentence of the discussion, the researchers concluded “…although the results were statistically significant, the changes in the CLA group were small, and one could question their clinical significance.”
I was very surprised by these comments. So I re-read the results and checked the data again.
The group given CLA demonstrated a gain in lean mass that was seven fold better than the placebo-treated group. Yes, 700% greater!
Whereas the placebo group gained almost half a kilogram of body fat, the CLA group lost almost a kilogram (2 pounds) of pure body fat.
These differences were apparent after just seven weeks!
The correct statistical assessments were utilized on the data to ascertain significance. Most importantly, significance was achieved utilizing a large group of resistance-trained participants.
The bottom line is, results don’t get any clearer or more compelling.
The cross-over part of the trial did not tend to yield supportive results. However, it’s important to remember that CLA is a bioacitve lipid, its beneficial effects on the metabolism could remain for weeks or even months. Also, only 17 subjects participated in this part of the study, as opposed to the 76 that completed the initial 7 week trial. Even so, the data still showed a consistent benefit from CLA on reducing muscle catabolism throughout both trials. Despite these outstanding results, the scientists suggested the findings have little relevance.
A seven-fold greater gain in lean mass and a loss of almost one kilogram of body fat in seven weeks is darn relevant in my book. I’m sure that virtually any bodybuilder would agree with me.
I understand that scientists have to be conservative when interpreting findings. However, the interpretation of the results by the authors boarders on the ridiculous. It makes me think there may have been a hidden agenda involved.
Some media and health professionals have presented the watered down version of this research. However, I’ve highlighted some key aspects of this study to provide you with the clear facts. The data doesn’t lie.
I’m sure you can make up your own mind as to where or not a 700% better gain in muscle mass combined with a one kilogram loss of body fat in just seven weeks is “relevant”.
Source: Pinkoski C, et al.The effects of conjugated linoleic acid supplementation during resistance training. Med Sci Sports Exerc. 38(2):339-48, 2006.