Recently I posted about a well-known fact, we now call “muscle memory”. Underneath this article you can find the links to these blog posts.
A high-level power-lifter from Sweden that happens to be a scientific researcher was fascinated by this process and wanted to know what long-term (10 years and longer) short-term (cycle of 20 weeks) did to muscles compared to natural power-lifters.
He compared his research with other similar studies. He also wanted to know what the difference could be of training with or without anabolic steroids long term or short term to an isometric contraction such as the dead-lift compared to a maximal explosive exercise such as the squat.
First an overview of the muscle fibers involved.
There are three primary muscle fiber types in humans -- Type I, Type IIA, and Type IIB. Type I are referred to as "slow twitch oxidative", Type IIA are "fast twitch oxidative" and Type IIB are "fast twitch glycolytic" As their names suggest, each type has very different functional characteristics. Type one fibers are characterized by low force/power/speed production and high endurance, Type IIB by high force/power/speed production and low endurance, while Type IIA fall in between. These characteristics are a result, primarily, of the fiber's Myosin Heavy Chain (MHC) composition, with Mysosin heavy chain isoforms I, IIa and IIx corresponding with muscle fiber types I, IIA, and IIB.