Aging impairs the skeletal muscle's ability to regulate oxidative stress during exercise, characterized by reduced mitochondrial DNA copy number, increased DNA mutations, and aberrant redox protein responses. This disconnect between preserved aerobic capacity and compromised stress-response signaling explains why older adults may show diminished training adaptations despite completing the same exercise stimulus.
Key Points
- Older adults show lower mtDNA copy number and higher mutation frequency
- Exercise triggers excessive oxidation of antioxidant proteins in aged muscle
- Mitochondrial DNA stability predicts quality of exercise-induced redox response
Longevity Analysis
The capacity to interpret and resolve exercise-induced oxidative signals deteriorates with age, independent of baseline aerobic function. This represents a decoding failure: the muscle receives the same stimulus but misinterprets it, triggering maladaptive redox remodeling rather than beneficial adaptation. The findings indicate that older adults may require different exercise modulation strategies—intensity timing, duration, or recovery protocol—to restore appropriate stress-response signaling and preserve training responsiveness. Restoring mitochondrial genomic stability emerges as foundational to reclaiming the body's ability to respond to physical challenge.
Original published by Wiley Aging Cell, by Bradley A. Ruple, Nicholas A. Carlini, Jason S. Kofoed, Helya Rostamkhani, Brady E. Hanson, Jesse C. Craig, Shelby C. Osburn, Allison M. Manuel, Paul A. Stewart, Jonathan Wanagat, Ryan M. Broxterman, Joel D. Trinity .