HILTON HEAD, SC--Anabolic steroids are synthetic hormones derived from the human male hormone testosterone. The use of steroids has been suspected in professional baseball and other sports where building muscle strength, rather than endurance, is paramount. Power lifting is such a sport. A team of researchers has examined the impact of anabolic steroid use on power lifters years after the athletes had ceased to take the drugs. The researchers found that while physical traces of the drug no longer remained, changes in the shoulder and quadriceps still gave lifters an advantage years later.

The research was conducted by Anders Eriksson and Lars-Eric Thornell, Department of Integrative Medical Biology, Section conducted the study for Anatomy, Umea University, Umea, Sweden; Christer Malm, Umeå University and Winternet and Patrik Bonnerud, Department of Health Science, Section for Medical Science, Lulea University of Technology, Lulea, Sweden; and Fawzi Kadi, Department of Physical Education and Health, Orebro University, Orebro, Sweden.

Dr. Eriksson will discuss the team's study, "Anabolic Steroids Withdrawal in Strength Trained Athletes: How Does It Affect Skeletal Muscles?," at a conference sponsored by the American Physiological Society (APS; www.The-APS.org). The conference, The Integrative Biology of Exercise V, will be held September 24-27, 2008 in Hilton Head, SC.

Background

Power lifting is a strength sport, requiring the use of a heavy dumbbell to perform three repetitions each of a squat, a bench press and a dead lift. It is in some ways similar to weight lifting, but where weightlifting is a dynamic sport, power lifting is a static one.

Power lifters focus on body strength, which relies heavily on muscle. The body's main muscle fiber types: type I, type IIA and type IIB. Type I is the weakest and slowest, but has the most endurance. Type IIA is the strongest and fastest, but has the least endurance. Human muscles occur along a continuum of fiber types. For power lifters, type IIB fiber, the most powerful, is most frequently used. The use of anabolic steroids can add more nuclei to the muscle, and enhance muscle fiber size.

The researchers examined data in two muscles: the vastus lateralis, found in the quadriceps, and the trapezius, a part of the shoulder-neck muscle. Each muscle is key to power lifting.

Three groups were examined. One group was comprised of seven power lifters who had previously used anabolic steroids for long periods of time but stopped their usage some years ago (PREV). One group was currently power lifting but did not use steroids (P). The third group was power lifting and taking steroids (PAS). The researchers examined muscle fiber distribution, fiber area, subsarcolemmal and internal myonuclei number per fiber, myonuclei expressing androgen receptors, satellite cell numbers per fiber, and proportion of split fibers in each muscle for each individual.

Findings

The researchers found that several years after anabolic steroid withdrawal, and with no or low current strength-training, the muscle fiber area intensity, the number of nuclei per fiber in the quadriceps was still comparable to that of athletes that were currently performing high intensity strength-training. They also discovered that the shoulder-neck fiber areas were comparable to high-intensity trained athletes and the number of nuclei per fiber was even higher than found in the current steroid-using group.

Conclusions

According to the lead researcher, Dr. Eriksson, "It is possible that the high number of nuclei we found in the muscle might be beneficial for an athlete who continues or resumes strength training because increased myonuclei opens up the possibility of increasing protein synthesis, which can lead to muscle mass." He added, "Based on the characteristics between doped and non-doped power lifters, we conclude that a period of anabolic steroid usage is an advantage for a power lifter in competition, even several years after they stop taking a doping drug."

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Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS; www.The-APS.org/press) has been an integral part of this discovery process since it was established in 1887.

NOTE TO EDITORS: The APS Conference, The Integrative Biology of Exercise V, is being held September 24-27, 2008 in Hilton Head, SC. Members of the media are invited to attend. To register, or to schedule an interview with Dr. Eriksson, please contact Donna Krupa at 301.634.7209 (office), 703.967.2751 (cell) or DKrupa@the-APS.org. There will be an APS newsroom onsite.