When you talk about growth-promoting effects in skeletal muscle, glutamine and branched-chain amino acids seem to get the vast majority of attention from the iron-pumping crowd. Lysine, however, is an amino acid that can't he ignored, and a group of researchers from the
University of Illinois in Urbana has examined the role of lysine supplementation on growth and protein accretion in skeletal muscle of rats.
Male rats in one of five diet groups were fed either a wheat gluten-based diet or a wheat gluten-based diet with adequate levels of lysine. Gluten is a protein prepared from wheat or other grains. The rats were fed either as much as they wanted (ad lihitum) or at a 75% restricted level. After six weeks, researchers found that lysine supplementation produced higher levels of protein, RNA and DNA in skeletal muscle and liver of the animals fed ad lihitum. Food restriction produced a drop in protein and RNA from the liver and skeletal muscles, yet supplementation with lysine didn't seem to help. In the rats fed ad lihitum (the condition that most closely resembles how bodybuilders eat), lysine helped increase the weight of the soleus and plantaris muscles by approximately 50%! In addition, the body weights of these rats increased by 33% over those of the non-supplemented group. Study authors believe lysine helps increase protein levels in the tissues studied in one of two ways:
An increased efficiency by which RNA is used to make proteins or a decrease in protein degradation (an anticatabohc effect).
Lysine plays a potentially significant role in the strength athlete's anabolic process. Whether you're a competitive or recreational bodybuilder, perhaps it would be a wise idea to consume a lysine supplement to maximize the growth-promoting processes.