A very interesting study was published last year involving the supplement Conjugated linoleic acid (CLA) and its effect on muscle mass during training. This report has been overlooked by the bodybuilding community. However, its results are very relevant to all strength athletes, for a number of reasons.
Firstly, this study is one of very few that have examined the effects of supplementation with CLA during a structured training program. Secondly, it utilized a large group of resistance-trained participants. Using this protocol, the results obtained with CLA were quite simply, remarkable.
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 study, its 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 obtained from CLA in this research.
However, these important findings have been overlooked or ignored by most bodybuilding journalists that bother to take a look at the research. This is probably because of the conclusions made by the authors of this study. In the published manuscript the authors conclusions of the findings were quite different – subdued to say the least. Within the the discussion section of this paper, 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. The data was as clear as night and day.
- 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.
While the cross-over part of the trial did not tend to yield supportive results, 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, within this cross-over part of the study (that used a much smaller number of participants) the data still showed a consistent benefit from CLA on reducing muscle catabolism. Now, despite these outstanding results the scientists suggested that the findings have little relevance. How they came to that conclusion is beyond me. Where is the common sense?
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 presented by the authors boarders on the ridiculous. It makes me think there may have been a hidden agenda involved.
- 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.
Based on the authors recommendations, some health professionals have presented a very watered down version of this research in the media. 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 whether 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.
