A recent study by scientists from the University of Oslo have found that athletes' muscles can retain the performance-enhancing benefit of anabolic steroids years, or even decades, after taking them.
The research was conducted last October by Professor of Physiology, Kristian Gundersen, who told the BBC: "I think it is likely that effects could be lifelong or at least lasting decades in humans.
"Our data indicates the exclusion time of two years is far too short. Even four years is too short."
The study, conducted on mice, throws into doubt the results of post-ban dopers in athletics, but also highlights the need for research into the long-term effects of using other substances in endurance sports such as cycling.
Further research undertaken by Dr Jo Bruusgaardat the University of Olso – published last December – showed that mice given a 14-day treatment of testosterone rapidly developed the myonuclei within muscle cells that allows the muscle cells to grow bigger and stronger when trained. Even once the treatment had been finished, the number of myonuclei remained for three months, making it easier to return to strength even after de-training.
Pertinent to both studies, Gundersen told the BBC: “I would be very surprised if there were any major differences between humans and mice in this context.
"The fundamental biology of muscle growth is similar in humans and in mice, and in principle any drug that builds muscle mass could trigger this mechanism.
"If you exercise, or take anabolic steroids, you get more nuclei and you get bigger muscles. If you take away the steroids, you lose the muscle mass, but the nuclei remain inside the muscle fibres.
"They are like temporarily closed factories, ready to start producing protein again when you start exercising again."
Three months for a mouse equates to around 10 human years. Such a period of time again calls into question whether post-ban dopers still benefit from their illegal practices years after returning to sport. Further analysis relating to endurance sport is ongoing, but it appears the unfair advantage could be much further reaching than time-penalties served up for being caught.
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