How exercise preserves physical fitness during aging

 

 Proven to protect against a wide array of diseases, exercise may be the most powerful anti-aging intervention known to science. However, while physical activity can improve health during aging, its beneficial effects inevitably decline. The cellular mechanisms underlying the relationship among exercise, fitness and aging remain poorly understood.  

In a paper published in the Proceedings of the National Academy of Sciences, researchers at Joslin Diabetes Center investigated the role of one cellular mechanism in improving physical fitness by exercise training and identified one anti-aging intervention that delayed the declines that occur with aging in the model organism. Together, the scientists’ findings open the door to new strategies for promoting muscle function during aging.  

“Exercise has been widely employed to improve quality of life and to protect against degenerative diseases, and in humans, a long-term exercise regimen reduces overall mortality,” said co-corresponding author T. Keith Blackwell, MD, PhD, a senior investigator and section head of Islet Cell and Regenerative Biology at Joslin. “Our data identify an essential mediator of exercise responsiveness and an entry point for interventions to maintain muscle function during aging.” 

That essential mediator is the cycle of fragmentation and repair of the mitochondria, the specialized structures, or organelles, inside every cell responsible for producing energy. Mitochondrial function is critical to health, and disruption of mitochondrial dynamics  the cycle of repairing dysfunctional mitochondria and restoring the connectivity among the energy-producing organelles — has been linked to the development and progression of chronic, age-related diseases, such as heart disease and type 2 diabetes.  

“As we perceive that our muscles undergo a pattern of fatigue and restoration after an exercise session, they are undergoing this mitochondrial dynamic cycle,” said Blackwell, who is also acting section head of Immunobiology at Joslin. “In this process, muscles manage the aftermath of the metabolic demand of exercise and restore their functional capability.”