Volitional Weight-Lifting in Rats Promotes Adaptation via Performance and Muscle Morphology prior to Gains in Muscle Mass

Details

• Alternative Title:
  Environ Health Insights
• Personal Author:
  Rader, Erik P. ; Miller, G. Roger ; Chetlin, Robert D. ; Wirth, Oliver ; Baker, Brent A.
• Description:
  Investigation of volitional animal models of resistance training has been instrumental in our understanding of adaptive training. However, these studies have lacked reactive force measurements, a precise performance measure, and morphological analysis at a distinct phase of training - when initial strength gains precede muscle hypertrophy. Our aim was to expose rats to one month of training (70 or 700 g load) on a custom-designed weight-lifting apparatus for analysis of reactive forces and muscle morphology prior to muscle hypertrophy. Exclusively following 700 g load training, forces increased by 21% whereas muscle masses remained unaltered. For soleus (SOL) and tibialis anterior (TA) muscles, 700 g load training increased muscle fiber number per unit area by ∼20% and decreased muscle fiber area by ∼20%. Additionally, number of muscle fibers per section increased by 18% for SOL muscles. These results establish that distinct morphological alterations accompany early strength gains in a volitional animal model of load-dependent adaptive resistance training.
• Subjects:
  Fiber Cross-sectional Area Fiber Number Operant Conditioning Original Research Resistance Exercise Stereology
• Source:
  Environ Health Insights. 2014; 8(Suppl 1):1-9.
• Document Type:
  Journal Article
• Volume:
  8
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:ff4982b045955fae7255293c6145d2ea8da6ae5c023a0b9a55393b64eca92e03
• Download URL:
  https://stacks.cdc.gov/view/cdc/26072/cdc_26072_DS1.pdf
• File Type:
  [PDF - 1.71 MB ]