The Overlooked Culprit Behind Age-Related Muscle Loss
Using your muscles might be the anti-aging hack you need.
Sarcopenia (i.e., muscle loss due to aging) might not be inevitable. While many assume that aging naturally causes sarcopenia, research suggests that a decrease in resistance training could be the actual culprit. There are several factors that contribute to sarcopenia, including under-eating, which impacts protein intake, slowing metabolism, and chronic inflammation, but training consistently could meaningfully curb that trajectory.
What You Should Know About Aging Muscle
Sarcopenia is a significant concern for adults over 50. After that point, muscle mass drops by roughly 1 to 2% a year, and muscle strength declines about 1.5% a year through your 50s and closer to 3% a year after 60. Part of that is insufficient protein intake. Many older adults fall short of the 1 to 1.3 grams of protein per kilogram of body weight that research suggests they need to protect muscle — a higher target than the standard RDA.
A second contributor to sarcopenia is reduced levels of hormones that stimulate skeletal muscle mass, including growth hormone, testosterone, estradiol, and Vitamin D. At the same time, catabolic hormones — chief among them cortisol — can rise with age and speed up muscle breakdown.
A third contributor to sarcopenia is reduced activity, which is directly associated with increased body fat and decreased lean body mass. This combination reduces strength and force output, increasing the risk of falls and related injuries.
Going Deeper on the Culprit
The study by Andrew P. Wroblewski et al., published in The Physician and Sportsmedicine, challenges other sarcopenia studies for relying on sedentary older adults as participants.
The study examined whether chronic exercise combats the loss of lean muscle mass and strength by testing 40 Masters athletes aged 40 to 81 who trained four to five times a week, using MRI scans of their thighs and tests of how much force their quadriceps could produce.
Although they found that body fat percentage did increase with age, loss of force output and strength in the quadriceps did not. Maintaining force output was tied to muscle area, meaning that maintaining lean muscle mass also maintained strength.
Ultimately, their findings suggest that declining muscle mass and strength is not solely the result of aging. Instead, they suggest muscle disuse (i.e., lower physical activity) is the more significant factor in sarcopenia.
Although the sample size is small and more robust testing is needed to confirm that assertion, the potential for consistent training to combat aging is promising.
The Takeaway
The research suggests there are meaningful actions within your control when it comes to fighting age-related muscle loss. Aim to strength-train your major muscle groups at least twice a week, and spread your protein across the day — a solid dose at breakfast and lunch, not just dinner. Exposing your body to stimuli that remind it to retain lean muscle mass, combined with the fuel to maintain it, could help prevent muscle fragility that may lead to falls or other accidents.
Bottom Line
Though more robust evidence is needed to confirm that consistent resistance training and sufficient daily protein intake can prevent sarcopenia, their benefits remain worth leaning into. Always consult a physician before starting any training or dietary program. Whether future science confirms that sarcopenia results more from muscle disuse than aging, the latter is inevitable, but the former you can control now.
