Resistance exercise in older adults boosts levels of cardiotrophin-like cytokine factor 1—a myokine released during exercise—by nearly 70%, improving muscle strength, bone density, and metabolic functions. Digest
Aging compromises muscle strength and bone density, altering the signaling pathways that coordinate their function. These pathways involve myokines—hormone-like proteins released by muscle during exercise that help regulate metabolism, enhance muscle performance, and support bone formation. A recent study found that levels of a myokine called cardiotrophin-like cytokine factor 1 decline sharply with age but rise by nearly 70% following resistance exercise in both humans and mice.
Researchers measured cardiotrophin-like cytokine factor 1 levels in muscle and blood samples from young and older adults before and after single and long-term resistance training sessions. In younger participants, a single session triggered a sharp rise in cardiotrophin-like cytokine factor 1 levels. In older adults, however, levels only increased after 12 weeks of consistent training. The researchers linked this diminished response to a decline in cytokine receptor-like factor 1, a companion protein required for the myokine’s release.
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Then they restored cardiotrophin-like cytokine factor 1 levels in older mice and found that muscle strength, glucose tolerance, and mitochondrial activity improved. Bone density also increased as the myokine reduced bone-resorbing cells and boosted bone-forming cells. Blocking the myokine prevented these exercise benefits, confirming its essential role in maintaining musculoskeletal health.
These findings suggest that aging limits the body’s ability to produce key exercise-related proteins, potentially explaining why older adults respond more slowly to training. However, regular training counters these effects. Dietary protein intake influences the body’s response to training, too. Learn more in this clip featuring Dr. Stuart Phillips.