From the time you are born to around the time you turn 30, your muscles grow larger and stronger. But at some point in your 30s, you begin to lose muscle mass and function, a condition known as age-related sarcopenia or sarcopenia with aging. People who are physically inactive can lose as much as 3% to 5% of their muscle mass per decade after age 30. Even if you are active, you will still experience some muscle loss.
Although there is no generally accepted test or specific level of muscle mass for sarcopenia diagnosis, any loss of muscle mass is of consequence, because loss of muscle means loss of strength and mobility. Sarcopenia typically accelerates around age 75 -- although it may happen in people age 65 or 80 -- and is a factor in the occurrence of frailty and the likelihood of falls and fractures in older adults.
In Nora Ephron's best-selling book, I Feel Bad About My Neck, she laments the sorry state of her 60-something neck: "Our faces are lies and our necks are the truth. You have to cut open a redwood tree to see how old it is, but you wouldn't have to if it had a neck," she writes.
"Every so often I read a book about age, and whoever's writing it says it's great to be old. It's great to be wise and sage and mellow; it's great to be at the point where you understand just what matters in life. I can't...
Although sarcopenia is mostly seen in people who are inactive, the fact that it also occurs in people who stay physically active throughout life suggests there are other factors involved in the development of sarcopenia.
Researchers believe the following factors play a role:
Age-related reduction in nerve cells responsible for sending signals from the brain to the muscles to initiate movement
A decrease in the body's ability to synthesize protein
Inadequate intake of calories and/or protein to sustain muscle mass
Treatments for Sarcopenia
The primary treatment for sarcopenia is exercise. Specifically, resistance training or strength training -- exercise that increases muscle strength and endurance with weights or resistance bands -- has been shown to be useful for both the prevention and treatment of sarcopenia.
Resistance training has been reported to positively influence the neuromuscular system, hormone concentrations, and protein synthesis rate. Research has shown that a program of progressive resistance training exercises can increase protein synthesis rates in older adults in as little as two weeks.