Changes in neuromuscular performance and muscle fiber characteristics of elite power athletes self-administering androgenic and anabolic steroids.

Abstract

The influence of androgenic-anabolic steroid-induced changes in measures of body composition, muscle fiber characteristics and various aspects of the neuromuscular performance of the leg extensor muscles was investigated in five experimental and six control power athletes during the 24-week programmed strength training followed by the additional six week training without hormone drugs. The mean values of the dosages of self-administration during the 24-week period were 31.0 +/- 14.3 mg/day for anabolic steroids (methandienone, stanozolol, nandrolone) and 178.4 +/- 82.7 mg/week for testosterone. During the 24-week hormone period the experimental group gained in fat-free weight (p less than 0.01) and in the mean muscle fiber areas (p less than 0.01) of the vastus lateralis muscle while the corresponding gains in the control group were minor (NS). The increases of maximal isometric force in the experimental and control groups were 14.7% (p less than 0.01) and 6.1% (NS), respectively, and the values obtained in average load-vertical jumping height curves were improved significantly (p less than 0.05) only in the experimental group. Increases of 18.2% (p less than 0.001) and 12.9% (p less than 0.01) took place in the squat lift in the experimental and control groups, respectively. Both groups demonstrated similar (p less than 0.05) improvements in isometric fast force production. During the additional six week programmed training without hormone drugs significant (p less than 0.05) increases were observed in the experimental group in addition to maximal isometric force and the squat-lift but also in isometric fast force production, while the corresponding changes in the control group were minor (NS). It is suggested that strength training in combination with administration of androgenic-anabolic steroids causes improvements in selected neuromuscular parameters. These changes may be greater than those of caused by the strength training alone.