What is it supposed to do

The metabolism of AA is extremely complicated and far beyond the scope of this section.The many biologically active downstream metabolites of AA mentioned above are still under investigation, with new roles for each being discovered all the time. Relating to the issue that concerns the reader of this e-book (e.g., effects on strength, performance, and body composition), AA plays a role in the inflammatory response, which appears to have direct effects on protein synthesis. In particular, the prostaglandin PGF2a has been identified as an important mediator of protein synthesis. In theory, an increase in the tissue levels of PGF2a (via ingestion of AA) might alter the anabolic to catabolic balance which would increase muscle mass.

'achidoni^ Acid J

Other lines of evidence that support AA metabolites as being essential for protein synthesis come from studies that found that the cyclooxygenase (COX) enzyme inhibitors ibuprofen and acetaminophen greatly diminish the anabolic response to resistance exercise by inhibiting the normal postexercise increase in levels of PGF2a. As these OTC drugs exhibit their antiinflammatory actions by inhibiting the synthesis of prostaglandins, and it's been found they reduce protein synthetic rates in response to weight training, it's additional support for the concept that prostaglandins play an essential role in the anabolic response to exercise. Again, that's a generalization of an extremely complicated system.

The essential take home of the above is, prostaglandins are derived from dietary and in-vivo conversion of AA and appear up-regulate recovery mechanisms including: inflammation and protein synthesis within skeletal muscle in response to resistance training. What does the research have to say?

Most of the research that suggests AA has anabolic and or anti-catabolic effects via its conversion to PGF2a (and perhaps other metabolites yet to be elucidated) has been in-vitro (test tube) research. Other then intellectually interesting, very little can be concluded as it applies to living systems. Although there have been studies that examined the effects of humans ingesting AA, these studies did not examine the effects on whole body protein synthesis or skeletal muscle mass or tissue levels of PGF2a. However, one recent study did look directly at the effects of AA on strength and body composition.

The 50 day study consisted of thirty-one resistance-trained males who were randomly assigned to a placebo (P: n = 16; 1 g capsulated corn oil/day) or AA group (AA: n = 15; 1 g capsulated AA/day). Although diet was not controlled for (a major flaw of this study, BTW), they were given supplemental protein powder to assure an adequate protein intake while participating in a 4-day per week resistance training regimen which consisted of a twice per week upper/lower split.

The researchers examined various downstream metabolites of AA, such as: prostaglandin E2 (PGE2), prostaglandin F2a (PGF2a), interleukin-6 (IL-6), as well as hormonal effects on free testosterone, total testosterone and cortisol. They also took muscle biopsies to look at any changes in myosin heavy chain isoform. The study did not find statistically significant differences between the group getting the AA and the placebo group. There was a trend in the changes of some of the outcomes examined, but none of them reached statistical significance which equates to no differences between groups. The researchers concluded:

"Results suggest that AA supplementation during resistance training may exert some potentially favorable alterations IL-6 levels and prostaglandin levels and that additional research is necessary to further examine this hypothesis. "

Five Foods That Build Muscle

Five Foods That Build Muscle

How to properly fuel your body before and after your workouts, with the right nutrients and in the right way, for maximum results week after week! Find out why protein and hardwork is not enough...and why your results will suffer unless you add these other 5 foods to your muscle-building plan.

Get My Free Ebook

Post a comment