Ribosomes are the cellular “machines” that construct new proteins from amino acids. The instructions for how to create a certain protein are provided by molecules called RNA. Ribosomes read RNA molecules and use those instructions to link amino acids in a way that creates the type of protein specified by the RNA molecule. When we talk about muscle protein synthesis, we’re talking about the work of ribosomes - they are the ones that synthesize the proteins which become muscle tissue. Ribosomes have only a temporary existence and are constantly being produced and replaced in a process called ribosome biogenesis. Following strength training, ribosome biogenesis increases above baseline so that a higher number are present to synthesize the proteins necessary for repairing and growing the muscle fibers. But the increase in ribosome production following training appears to vary between people. Some individuals create more ribosomes than others and this allows them to synthesize protein at a higher rate, leading to faster muscle recovery and growth.