Anabolic steroids increase exercise tolerance

Area of Science:

• Exercise Physiology
• Muscle Biology
• Pharmacology

Background:

• Anabolic androgenic steroids (AAS) are performance-enhancing drugs.
• Weight lifting causes muscle damage and affects protein synthesis.
• The effects of AAS on muscle recovery post-exercise are not fully understood.

Purpose of the Study:

• To investigate the influence of nandrolone decanoate (an AAS) on muscle recovery after weight lifting.
• To assess thymidine and amino acid uptake, and myosin synthesis in rat skeletal muscles.
• To evaluate the impact of AAS on muscle damage and fatigue resistance.

Main Methods:

• Adult male rats were divided into Control and Steroid groups, with the Steroid group receiving nandrolone decanoate.
• Exercise was induced via a single exhaustive bout of weight lifting.
• [3H]thymidine and [14C]leucine labeling were used to measure cellular mitotic activity and amino acid uptake.
• Serum creatine kinase (CK) activity was measured as an indicator of muscle damage.
• In situ isometric mechanical properties of the plantaris muscle were assessed.

Main Results:

• Steroid group rats lifted more weight and had lower CK levels post-exercise, indicating less muscle damage.
• [3H]thymidine uptake was significantly lower in Steroid rats, suggesting reduced muscle damage.
• [14C]leucine uptake was higher at rest and recovered faster post-exercise in Steroid rats, indicating enhanced protein synthesis.
• Steroid group rats exhibited higher fatigue resistance in the plantaris muscle.

Conclusions:

• AAS treatment ameliorates muscle damage and enhances protein synthesis during recovery from weight lifting.
• AAS treatment improves work capacity and muscle fatigue resistance.
• These findings suggest potential benefits of AAS in muscle repair and performance, alongside reduced muscle damage.