Keep Moving and Slow Down the Aging Process

Sarcopenia, Aging, and the Role of Resistance Exercise

Loss of muscle mass and strength, known as sarcopenia, is a common feature of aging. Many older adults experience reduced appetite and consume less protein over time, which can contribute to progressive muscle loss and functional decline.

An article published in the Journal of the American College of Nutrition (2004; 23(6):601S–609S) reviewed the relationship between aging and muscle loss and highlighted the importance of resistance training. The authors noted that strength training increases muscle mass primarily through increased synthesis of contractile proteins. While the precise molecular mechanisms are not fully understood, resistance exercise—particularly eccentric (lengthening) muscle contractions—has been shown to cause microscopic muscle damage that may stimulate increased muscle protein turnover and growth.

More direct evidence comes from a study published in PLoS ONE (2007; 2(5):e465), which examined the effects of six months of resistance training in 25 healthy older adults compared with 26 younger adults. Prior to the intervention, muscle biopsies revealed that older adults exhibited gene-expression patterns consistent with mitochondrial impairment and aging. Functionally, older adults were 59% weaker than younger participants at baseline.

After six months of resistance training (completed by 14 of the older participants), strength improved substantially, with older adults now only 38% weaker than younger subjects. Remarkably, gene-expression analysis showed that many of the age-related transcriptional changes were reversed toward a more youthful profile. The authors concluded that resistance exercise can partially reverse muscle weakness at the physical level and substantially reverse age-related changes at the molecular level.

Exercise also appears to influence biochemical markers associated with aging. A study published in Experimental Gerontology (April 2014; 52:46–54) evaluated functional fitness and biochemical markers in elderly individuals. Physical performance was assessed using handgrip strength, a six-minute walk test, chair-stand tests, and timed mobility assessments.

Researchers found that individuals with better physical performance also demonstrated more favorable biochemical profiles. More active participants tended to have lower cholesterol levels and reduced lipid peroxidation, a marker of oxidative stress linked to tissue damage and aging. They also had higher plasma levels of coenzyme Q10. The authors concluded that physical activity at advanced age may increase CoQ10 levels and reduce oxidative stress, potentially slowing processes associated with cardiovascular disease and aging.