Enhancement of skeletal muscle in aged rats following high-intensity stretch-shortening contraction training

Details

• Personal Author:
  Baker BA ; Chetlin RD ; Ensey J ; Layner KN ; Naimo MA ; Rader EP ; Triscuit AM
• Description:
  Exercise is the most accessible, efficacious, and multifactorial intervention to improve health and treat chronic disease. High-intensity resistance exercise, in particular, also maximizes skeletal muscle size and strength-outcomes crucial at advanced age. However, such training is capable of inducing muscle maladaptation when misapplied at old age. Therefore, characterization of parameters (e.g., mode and frequency) that foster adaptation is an active research area. To address this issue, we utilized a rodent model that allowed training at maximal intensity in terms of muscle activation and tested the hypothesis that muscles of old rats adapt to stretch-shortening contraction (SSC) training, provided the training frequency is sufficiently low. At termination of training, normalized muscle mass (i.e., muscle mass divided by tibia length) and muscle quality (isometric force divided by normalized muscle mass) were determined. For young rats, normalized muscle mass increased by approximately 20% regardless of training frequency. No difference was observed for muscle quality values after 2 days versus 3 days per week training (0.65 +/- 0.09 N/mg/mm vs. 0.59 +/- 0.05 N/mg/mm, respectively). For old rats following 3 days per week training, normalized muscle mass was unaltered and muscle quality was 30% lower than young levels. Following 2 days per week training at old age, normalized muscle mass increased by 17% and muscle quality was restored to young levels. To investigate this enhanced response, oxidative stress was assessed by lipid peroxidation quantification. For young rats, lipid peroxidation levels were unaltered by training. With aging, baseline levels of lipid peroxidation increased by 1.5-fold. For old rats, only 2 days per week training decreased lipid peroxidation to levels indistinguishable from young values. These results imply that, appropriately scheduled high-intensity SSC training at old age is capable of restoring muscle to a younger phenotype in terms of lipid peroxidation levels and muscle quality. [Description provided by NIOSH]
• Subjects:
  Age Factors Aging Animals Laboratories Lipids Musculoskeletal System Occupational Health Safety Staff Development
• Keywords:
  Activity Levels Adaptation Age-factors Age-groups Author Keywords: Dorsiflexor Muscles Dynamometer Fisher 344XBrown Norway Rats Intervention Intervention Effectiveness Laboratory-animals Laboratory Testing Lipid Peroxidation Models Muscle Contraction Muscle Physiology Muscles Muscle Tension Oxidative Stress Physical Exercise Physiology Repetitive Exposure Skeletal System Training

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• ISSN:
  1549-1684
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  93-102
• Volume:
  20
• Issue:
  2
• NIOSHTIC Number:
  nn:20048686
• Citation:
  Rejuvenation Res 2017 Apr; 20(2):93-102
• Contact Point Address:
  Erik P. Rader, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, MS L3014, 1095 Willowdale Road, Morgantown, WV 26505
• Email:
  wlz4@cdc.gov
• Federal Fiscal Year:
  2017
• Peer Reviewed:
  True
• Source Full Name:
  Rejuvenation Research
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3e711488090ab400ad5ac59920224feef152b047b62039a2ab8bf8325c4227b33a5991cc1bb92846446ea0967796293629ccb07290707b061d80b8cccad49918
• Download URL:
  https://stacks.cdc.gov/view/cdc/203382/cdc_203382_DS1.pdf
• File Type:
  [PDF - 667.44 KB ]