It’s Part of the Aging Process
An age-related muscle mass loss is an inevitable part of growing older. Interestingly, it seems to occur in 2 phases. The first or “slow” phase of muscle loss is when about 10% of muscle mass is lost. This occurs between the ages of 25 and 50. The majority of muscle loss occurs thereafter… where an additional 40% is lost from the ages of 50 to 85. Overall, the human body loses 50% of its muscle mass by the age of 80.
The problems with decreasing strength can be seen in its contribution to the osteoporotic decline in bone density, arthritic joint pain, and an overall reduced functional capacity. With the loss of muscle mass evidently comes a decrease in muscular strength. Often noted is a decline in leg strength which precedes upper extremity strength loss, in the elderly. This likely contributes to most falls leading to injuries in the later years. An important and interesting fact to note is that strength, rather than cardiovascular function, is considered to be the most physically limiting factor in the elderly.
Slow Down the Loss and Enjoy Life
Regular exercise is the most effective way to slow and counteract the effects of age-related muscle and strength loss. Comparisons between active and sedentary older adults suggest that much of the strength loss with aging is due lifestyle factors. For example, individuals who continue to use certain muscles on a regular basis do not show the same age-related decreases in strength. In general, muscle atrophy, and thus strength loss, will occur any time the muscles are not required to work against a given load.
Building Muscles Strengthens Bones
Although there are certain unavoidable changes that occur with aging, it is possible to delay or lessen the loss of muscle mass and strength normally accompanying these changes. Encouraging studies have consistently shown that regular exercise can improve muscular endurance and strength in the elderly, in a manner similar to that observed in younger people.
The general weakening of both muscle tissue and our bones themselves, is a critical aspect of aging. One of the surest ways to reduce the stress on our weakening bones is to increase the muscles mass through strength training. Strength training has repeatedly been shown to be a safe and effective method of reversing muscle loss in the elderly.
It’s Not Too Late to Get Started
Since the muscles in older adults maintain their ability to adapt, implementing a program of regular exercise is top priority! 
This program should include resistance training perhaps (2-3x/week), into the lifestyle of such individuals. The regularity would benefit them greatly. As a matter of fact, younger adults should also be encouraged to follow a similar strength training protocol. Especially if their desire is to attain and maintain a fit and healthy body throughout their “golden years”.