Why can exercise delay muscle aging and help elderly people maintain strength? The research team led by Duke National University of Singapore School of Medicine has provided the answer at the molecular level. Research has found that exercise can help aging muscles restore protein renewal and self-healing abilities by regulating key genes DEAF1 and growth signaling pathway mTORC1. The relevant results were published in the latest issue of the Proceedings of the National Academy of Sciences in the United States. One of the key issues of muscle aging is the imbalance of protein "renewal". Under normal circumstances, the mTORC1 signaling pathway is responsible for regulating protein synthesis and clearance, maintaining muscle structure and function. However, as age increases, this pathway tends to become overactive and more inclined towards synthesizing new proteins, which slows down the clearance of damaged proteins, leading to increased cellular pressure and gradual muscle decline. The study identified the core role of gene DEAF1 in this process. It was found that an increase in DEAF1 levels in aging muscles will continue to push mTORC1 into an "overloaded" state, accelerating protein metabolism imbalance. Normally, DEAF1 is inhibited by the FOXO protein family, but FOXO activity decreases with age, causing DEAF1 to lose its restraint and exacerbating muscle degeneration. Research shows that as long as this regulatory system still has the ability to respond, exercise can reverse the aforementioned imbalance. Exercise can activate related proteins, reduce DEAF1 levels, restore balance of mTORC1 activity, help muscles clear damaged proteins, and restore repair function. The team metaphor is that exercise is equivalent to sending a "reset" signal to muscles. However, when DEAF1 remains at a high level for a long time or FOXO activity severely decreases, it may be difficult to fully restore muscle repair ability solely through exercise, which may explain the limited effectiveness of exercise interventions in some elderly people. (New Society)