Athletes caught using anabolic steroids to enhance their performance are currently excluded from competing for up to two years. However, the findings of a Norwegian study suggest that performance-enhancing drugs may lead to long-lasting, perhaps even permanent effects even after brief exposure to them. Professor Kristian Gundersen, leader of the research team from the University of Oslo, said that the study results could spark a debate over the existing code of the World Anti-Doping Agency (WADA).
The Norwegian researchers used mice as subjects for their investigation. According to the report, which has been published in the current issue of The Journal of Physiology, the mice were given brief exposure to steroids, the result being increased muscle mass and growth in the number of cell nuclei in their muscle fibres. Drug intake was stopped after three months, which amounts to roughly 15% of the longevity of a mouse. The researchers established that load exercise resulted in a 30% increase in muscle mass within six days. In contrast, the mice that did not get drugs showed insignificant growth.
So far, muscle mass re-acquisition after inactive periods has been ascribed to motor learning. But the findings of this study suggest the existence of a cellular “memory mechanism” in the muscles of brief steroid users. As Gunderson explained, the time recorded for mice could correspond to decades in a human lifespan provided the same mechanism is present. Future studies need to focus on human muscles and look deeper into the cellular and molecular mechanism for muscle memory, Gunderson added.