Although steroids and training are a bit outside of the lab's research interests, they appear to be a topic of great general interest.
All anabolic steroids are chemical derivatives of the male sex hormone, testosterone.
Due to testosterone's short biological half-life, pharmacological use requires the steroid be modified to slow metabolism by the liver. Like all steroids, the steroid-receptor complex has a strong affinity for the nucleus. It is also possible that the steroid and receptor dissociate in the nucleus and act on DNA separately. The rate limiting factor in this process appears to be the cytoplasmic concentration of the receptor, rather than the concentration of the steroid or translocation of the complex. Once in the nucleus, the steroid appears to enhance transcription of specific genes.