Researchers from the Norwegian School of Sport Sciences have determined that muscles possess a molecular memory capable of recording periods where physical activity was absent. Furthermore, the mechanisms underpinning this memory differ between younger and older subjects.
The investigators, as reported by the journal Advanced Science, examined how temporarily restricting mobility in the lower limbs affected skeletal musculature. Young human volunteers participated in the study, and to assess age-related differences, elderly rats were observed concurrently.
The findings indicated that in young individuals, subsequent periods of inactivity resulted in a decrease in muscle mass comparable to the initial instance. However, at the molecular level, they developed a form of defense. During the second period of low activity, alterations in the genes governing cellular energy metabolism were less pronounced. This suggests an adaptation process leading to enhanced resilience in the muscle tissue.
Conversely, in aging muscles, a detrimental memory regarding the lack of loading emerged. Reintroducing restricted mobility triggered more substantial atrophy, suppression of energy production pathways, and the activation of DNA damage mechanisms. The scientists observed similar genetic-level shifts across different species, implying that molecular markers of muscle weakening persist over extended durations.
Professor Adam P. Sharples, a co-author of the study, emphasizes that muscles retain recollections of both periods of strength and decline. These molecular imprints can accumulate and influence how the body responds to periods of inactivity. According to him, comprehending these processes is vital for developing more effective recovery strategies following injuries, illnesses, and age-related degeneration. The team is currently investigating which specific types of physical exercises are most effective at promoting beneficial memory within cells, particularly for older populations.
About the Author
