This is the first scientific evidence identifying changes in protein secretion as a major reason for the reduced efficacy of exercise in aging individuals

"Exercise is good for your health" is a well-known phrase, but few people can clearly explain how and why it benefits the human body. 

A joint research team has discovered a key protein, CLCF1 (cardiotrophin-like cytokine factor 1), that plays a central role in mediating the health benefits of physical activity.

June 20, 2025

Exercise-induced protein revives aging muscles and bones, researchers discover

by National Research Council of Science and Technology

edited by Gaby Clark, reviewed by Robert Egan

 

 

 

CLCF1 inhibits osteoclast differentiation and stimulates osteoblast differentiation. Credit: Natu

 

The work is published in the journal Nature Communications. The team was led by Dr. Yong Ryoul Yang of the Aging Convergence Research Group at the Korea Research Institute of Bioscience and Biotechnology (KRIBB, President: Seok-Yoon Kwon) and Professor Nak-Sung Kim of Chonnam National University. . .

The team found that CLCF1 is secreted by muscles during exercise, where it helps strengthen both muscles and bones, thereby suppressing musculoskeletal aging.

 > Further analysis showed that CLCF1 

• enhances mitochondrial function in muscle cells, 
• inhibits the formation of bone-resorbing osteoclasts, and 
• promotes the differentiation of bone-forming osteoblasts. 

This is the first scientific evidence identifying changes in protein secretion as a major reason for the reduced efficacy of exercise in aging individuals.

 

Dr. Yang from KRIBB said,  

"This research provides a biological basis for why exercise becomes less effective with age, and it lays the groundwork for developing new therapeutic strategies for healthy aging. In particular, the findings offer new directions for treating age-related sarcopenia and osteoporosis."