Steroids' Benefits Could Ripple for Months, Years Current bans on athletes who test positive might not be enough By Ruth Brown, Newser Staff Posted Oct 30, 2013 9:50 AM CDT 14 comments Comments (Shutterstock) (Newser) – Steroids may give athletes a competitive edge way longer than previously thought—as long as their entire professional careers. A new study from Norway found that mice given steroids were able to regrow muscle mass more rapidly months after the drug was withdrawn. After three months "clean," the 'roided-up mice grew their muscles 30% after six days of exercise. Mice who took no drugs only gained 6% more muscle, the BBC reports. Three months may not sound like a lot, but it is 15% of a mouse's average lifespan, notes the Australian. The new research raises the question of how long athletes should be banned from competing after being caught doping. Standard doping bans are two to four years, but the leader of the study says that may not be nearly long enough. "If it is sufficient to build muscle mass, I think it would be sufficient to give you this long-term effect," he says, per the BBC. "I think it could last 10 years but I don't have the data to back that up. It would be my speculation."