Sarcopenia muscle loss with aging
November 13, 2011
by Gabe Mirkin, MD

Competitive masters athletes, 40 to 81 years old, who 
trained four to five times per week did not lose any 
muscle size or significant strength with aging (The 
Physician and Sportsmedicine, October 2011;39(3):172-8). 
This shows that loss of muscle size and strength in 
older people is caused by lack of exercise, not just 
with aging. The athletes did gain fat in spite of 
exercising. Those in their 70s had almost as much 
strength and thigh muscle size as those in their 40s.
 
MOST PEOPLE LOSE MUSCLE: Recent studies show that after 
age 40, men lose more than eight percent of their muscle 
size each decade, and this loss of muscle increases 
after age 70. The people who lose the most muscle are 
usually the ones who die earliest. They are also most at 
risk for falls and broken bones.
 
HOW EXERCISE PREVENTS MUSCLE LOSS WITH AGING: Muscles 
are made up of thousands of individual muscle fibers. 
Each muscle fiber is innervated by a single nerve. With 
aging, humans lose the nerves that innervate muscle 
fibers, and with each nerve loss, they lose the 
associated muscle fiber so muscles become smaller. 
We used to think this happens because of aging. However, 
this new study and others show that lifelong competitive 
athletes do not lose the nerves that innervate their 
muscles with aging. They retain the nerves and therefore 
retain most of the muscle fibers that they would have 
lost if they were inactive.
 
MESSAGE: If you exercise regularly, continue to do so. 
If you dont, check with your doctor and then get 
instructions on how to start an exercise program.