Resistance training and glycogen content in ovariectomized rats

Area of Science:

• Exercise Physiology
• Endocrinology
• Skeletal Muscle Biology

Background:

• Ovariectomy in rats mimics menopause, leading to hormonal changes.
• Estrogen and progesterone influence muscle metabolism and mass.
• Resistance training is known to impact muscle adaptations.

Purpose of the Study:

• To examine resistance training effects on glycogen and muscle cross-sectional area (CSA) in ovariectomized rats.
• To determine if resistance training can counteract ovariectomy-induced changes.
• To assess the role of hormones in exercise-induced muscle adaptations.

Main Methods:

• Wistar rats were divided into four groups: sedentary, ovariectomized sedentary, resistance trained, and ovariectomized resistance trained.
• A 12-week resistance training program involved vertical ladder climbing.
• Glycogen content (cardiac, liver, muscle) and soleus muscle CSA were measured.

Main Results:

• Resistance training significantly increased hepatic and muscle glycogen content compared to controls.
• Soleus muscle CSA was higher in trained groups, including ovariectomized rats, versus sedentary ovariectomized rats.
• Ovariectomy partially reduced the gains in liver and muscle glycogen from training.

Conclusions:

• Resistance training enhances glycogen storage and muscle CSA, even in the absence of ovarian hormones.
• Exercise may be a valuable intervention for maintaining muscle function during hormonal decline.
• These findings highlight the potential of resistance exercise for mitigating menopausal-related muscle changes.