Age Related Muscle Loss
By: Dale J. Buchberger, PT, DC, CSCS, DACBSP
Sarcopenia is increasingly recognized as a serious health problem that afflicts millions of aging adults and places and continues to strain our health care system. Since the 1960’s the growth of the U.S. population over the age of 65 has doubled in size when compared to the general population. In the year 2000, the number of men and women over the age of 65 in the United States was projected to increase to 32 million people, which was approximately 20% of the population. The geriatric population, those over the age of 75, is increasing at an even faster rate.
From birth until you turn 30, your muscles continue to grow bigger and stronger. But at some point in your 30s, you will lose muscle mass, strength and function, a condition known as age-related sarcopenia. People who are sedentary or physically inactive can lose approximately 3% to 5% of their muscle mass per decade after the age of 30. Normally, adults who are sedentary beyond the age of 50 can expect a loss of muscle mass of up to 0.4 pounds a year. Unfortunately, even if you life an active lifestyle, the human body continues to lose muscle mass as we age.
Although there is no generally accepted test or specific level of muscle mass that leads to a diagnosis of sarcopenia, any loss of muscle mass is ultimately a problem, because lost muscle mass means a loss of strength and mobility. While sarcopenia typically begins after the age of 30 it picks up steam after age 50 and accelerates around the age of 75. Sarcopenia is also a factor in the occurrence of age related deterioration and an increase in the rate of falls and fractures in aging adults.
Symptoms of muscle loss include musculoskeletal weakness and loss of endurance, which can interfere with the ability to be physically active. Reduced physical activity then creates a cycle of deconditioning that further reduces muscle mass. Therefore, while engaging in regular physical activity is essential to avoiding sarcopenia, inactivity is not the only contributing factor to this condition. Although sarcopenia is commonly seen in people who are sedentary or 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. Like osteoporosis, sarcopenia is a multifactorial disease process that may result from dropping hormone levels, an inadequate amount of dietary protein, coexisting nutritional imbalances, lack of exercise, oxidative stress, age-related reduction in nerve cells responsible for sending signals from the brain to the muscles to initiate movement and chronic inflammation. Although sarcopenia is commonly seen in people who are sedentary or 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.
The question remains, “what can we do to slow the onset or progression of sarcopenia”. Through resistance training exercise adults can improve their ability to stand up from a seated position, walk household and community distances, safely climb a flight of stairs or anything that requires moving their own body weight through a range of motion during activities of daily living.
Current research shows that the most important factor in a person’s function is their strength capacity. Regardless of a person’s age, they can experience significant strength improvement with a progressive resistance exercise program even into their eighth and ninth decades of life. Progressive resistance training means that the amount of weight used, and the frequency and duration of training sessions is altered at various points in the program to accommodate for an individual’s improvements. An article published in The American Journal of Medicine, shows that after approximately 18-20 weeks of progressive resistance training, an adult can add 2.42 pounds of lean muscle to their body mass and increases their overall strength by 25-30 percent. Anyone over the age of 50 should strongly consider participating in progressive resistance exercise.
A good way for people to start on a progressive resistance-training program, especially for people who are relatively sedentary is to use their body mass as a source of resistance for a variety of exercises. Exercises you can do using your own body weight include squats, standing up out of a chair, modified push-ups performed on your knees or against a wall, lying hip bridges, as well as non-traditional exercises that progress through a full range of motion, such as Thai Chi or Pilates and Yoga. The simplest exercise is to go for a long walk with one or two pound weights in each hand. This is a form of weight bearing exercise combined with resistance. As we age it is natural to want to reduce our activity, but it is important to resist the urge to become sedentary and do the opposite; get active.