Successful maintenance activity remains a challenging area of research because of the multifactorial contributions of age, nutrition, hormones, medical comorbidities, and activity level to changes in muscle over time.
There is a spectrum of changes in aging muscle, some of which are normal and some of which are not.
Sarcopenia has been more quantitatively defined as relative muscle mass less than 2 standard deviations below a sex-matched control group aged 18 to 40 years, but the lack of a clear definition has resulted in a wide range of prevalence from 8% to 40%. The 2010 European Working Group on Sarcopenia in Older People defined 3 stages of this process: presarcopenia is simply loss of muscle mass, sarcopenia is muscle loss that occurs …show more content…
Our understanding of aging muscle is limited in several respects.
Mitchell compared changes in muscle mass as a factor of global changes in body composition with age.
Muscle mass decreases with advancing age, with men losing more absolute and relative muscle mass.
Mitchell's group reported a 0.5% to 1.0% loss of muscle mass per year after 70 years of age and a 4.7% loss compared with peak mass in men and 3.7% decrease for women per decade.
Frontera presented one of the more thorough descriptions of aging skeletal muscle mass.
Enzymatic changes in energy production occur with age; anaerobic enzymes seem to remain constant with age, while aerobic energy production is decreased with age. Age-related changes in muscle fiber distribution have been identified.
While there is no consensus as to the exact numbers, it is clear that aging leads to an increasing percentage of type I fibers compared to type II. Similarly, general muscle strength decreases with age, possibly related to decreased contribution from the progressively smaller numbers of large tension-producing type II
There is a spectrum of changes in aging muscle, some of which are normal and some of which are not.
Sarcopenia has been more quantitatively defined as relative muscle mass less than 2 standard deviations below a sex-matched control group aged 18 to 40 years, but the lack of a clear definition has resulted in a wide range of prevalence from 8% to 40%. The 2010 European Working Group on Sarcopenia in Older People defined 3 stages of this process: presarcopenia is simply loss of muscle mass, sarcopenia is muscle loss that occurs …show more content…
Our understanding of aging muscle is limited in several respects.
Mitchell compared changes in muscle mass as a factor of global changes in body composition with age.
Muscle mass decreases with advancing age, with men losing more absolute and relative muscle mass.
Mitchell's group reported a 0.5% to 1.0% loss of muscle mass per year after 70 years of age and a 4.7% loss compared with peak mass in men and 3.7% decrease for women per decade.
Frontera presented one of the more thorough descriptions of aging skeletal muscle mass.
Enzymatic changes in energy production occur with age; anaerobic enzymes seem to remain constant with age, while aerobic energy production is decreased with age. Age-related changes in muscle fiber distribution have been identified.
While there is no consensus as to the exact numbers, it is clear that aging leads to an increasing percentage of type I fibers compared to type II. Similarly, general muscle strength decreases with age, possibly related to decreased contribution from the progressively smaller numbers of large tension-producing type II