JAN 06, 2023

Exercise Preserves Physical Fitness During Aging: Scientists Are Beginning to Understand Why

WRITTEN BY: Zoe Michaud

Regular exercise is known to have numerous health benefits for people who are aging. Exercise can help to improve strength, flexibility, and balance, which can, in turn, improve overall physical function. Many of the health problems that seem to come with age can be delayed by exercise. 

Though the cellular mechanisms underlying the relationship between exercise, fitness, and aging have historically been poorly understood, scientists are beginning to understand them. In a paper published in the Proceedings of the National Academy of Sciences, a group of researchers investigated one of the cellular mechanisms involved in improving physical fitness by exercise. 

The Joslin Diabetes Center research group believes that understanding the underlying mechanisms of how exercise benefits the aging process could offer future research pathways. Co-corresponding author T. Keith Blackwell, MD, PhD, says that “our data identify an essential mediator of exercise responsiveness and an entry point for interventions to maintain muscle function during aging.” 

The researchers found that the cycle during which mitochondria fragment and repair is key to understanding the benefit of exercise on aging. After a person exercises, their mitochondria undergo a cycle of fragmentation and repair. 

“As we perceive that our muscles undergo a pattern of fatigue and restoration after an exercise session, they are undergoing this mitochondrial dynamic cycle. In this process, muscles manage the aftermath of the metabolic demand of exercise and restore their functional capability,” Blackwell adds.  

The group’s research took place using the model organism C. elegans, a species of worm that is frequently used in metabolic and aging research. During the animals’ 15 days of adulthood, the researchers observed their age-related decline in physical fitness. They found that in aging C. elegans, there was a significant increase in fragmented or disorganized mitochondria. 

“We determined that a single exercise session induces a cycle of fatigue and physical fitness recovery that is paralleled by a cycle of the mitochondrial network rebuilding,” said study author Juliane Cruz Campos. “Aging dampened the extent to which this occurred and induced a parallel decline in physical fitness. That suggested that mitochondrial dynamics might be important for maintaining physical fitness and possibly for physical fitness to be enhanced by a bout of exercise.”  

Sources: Centers for Disease Control and Prevention, Proceedings of the National Academy of Sciences