Wait atleast 12 months before attempting a cycle after being out for awhile. Your brain and muscles have to learn to have a "conversation" again. You can however supplement with the basics to help the process out - protein - BCAA's - multi-vitamin - fish oil... and even a stack of RPM / DRIVE / POWERFULL would be great. Here's a bit of information on muscle memory that I hope does you some good.
"Muscle memory" actually has nothing to do with weight training or anything of the topic. Muscle memory is the when repetitious actions performed by any muscle become faster and more effortless on the brain and eventually are done on almost a "subconcious" level (such as an assembally line worker reaching for an item hundreds of times daily and is able to do it with out having to "think" about it). This is due to the brain getting somewhat used to the nervous system sending the same impulses to the brain and the brain giving priority to it. The fact is that muscles dont actually attrophy, turn to fat or dissapear. Attrophy is possible but not due to the normal weight trainer stopping lifting under normal conditions. The muscles actually shrink in a sense. Your body builds muscle on a supply and demand concept. If a person lifts an object with his left hand over and over, day after day, the amazingly adaptable human body will grow new strands of muscle tissue in the muscles used for this type of lifting. Its not scar tissue, contrary to what most people think. If that was the case cutting your muscles with a scalple would strengthen you. The cells in a frequently used muscle are filled with more blood than other muscles. This is because blood carries oxygen to the muscle which it needs to keep up with the demand on it. When its priority changes so does its state. THis is the "shrinkage" you see when someone comes out of a cast and the extremity looks almost deathly. The reason an athelete can recover his/her muscle size/strength back after a bad injury is because the growth process has already taken place and the muscle simply needs to be "re-vascularized" and the body needs a bit of repetition to understand that the stress you are placing on it, is going to happen often and thus it will need to "wake" that part up again.
I hope this information helps you out. Being that I am in the process of becoming a DR specializing in PHY. Therapy and Sports Rehab - any questions that you may have please feel free to ask and I will help out as much as possible! Good Luck!
