AGEING  / MUSCLES  /  EXERCISE

A number of people have produced some excellent research papers on muscles and ageing. and summaries of their research is widely available on the internet. See the separate papers of: W. Frontera, H. Larson, M.A Fiaterone, D. A. Skelton, S. Melov, P.H.Fentem and many others. Modern thinking is that we are not pushing elderly participants hard enough and early approaches had assumed older people could not withstand anything beyond very low intensity training.

The Health Education Authority has a number of courses and articles on the types of exercises best suited for people over the age of 55. The papers and books by Dr Dawn Skelton are recommended reading.

A  summary of their findings is given below:

From age 20 on you can lose up to 10 percent of fast twitch muscle fibres for each decade of life ~ three kilos of lean body mass every ten years This means by age 50 you can lose 30% of the muscles used to get you in and out of a car, up out of a chair, allow faster walking speeds, loading groceries and lifting and carrying smaller children. The change occurs so gradually you don’t get a chance to put your finger on it until the fibre loss is significant enough to affect your quality of life. In Dr D Skelton’s book Exercise for Healthy Ageing the figure for muscle loss is quoted as sometimes being higher (1-2% per annum), The loss accelerates after the age of 60.

Your muscles are also made up of individual cells. No study has ever shown that it is possible to increase the total number of muscle cells that you have, although vigorous exercise can cause individual muscle cells to grow larger.

As well, with age, the muscle cells that remain start to atrophy. Each individual cell gets smaller and as a consequence the muscles can't contract with as muscle force. The end result; decreased muscular strength. A decline in muscle strength and size is not however inevitable.

In 1984 P.H.Fentem [Physio Dept, Nottingham Hospital] reported increases in muscle tone and 10% increases in bone density with people aged seventy and over by simple exercises in movement and bone loading.

In more recent times, the work carried William Frontera' saw people aged between 60 to 72 years regularly exercise and concentrating  on the thigh muscles [the quadriceps and the hamstrings]. Bearing in mind that the participants, before the start of the project, had lost a high percentage of their muscle tissue, he encouraged participants to train at 80 percent of their One Repetition Maximum (1RM ). [ 1RM is defined as the most weight a person can lift with one try ]. The amount of weight lifted was increased every week as participants were getting stronger. The research results showed the strength of the participants' quadriceps more than doubled and the hamstrings tripled.

Another specialist in geriatric medicine, Maria A Fiatarone M.D, expanded on Frontera's research by working with frail, institutionalised elderly people. Her research study was conducted at the Hebrew Rehabilitation Centre for the Aged, a chronic care hospital. The group consisted of ten men and women ranging in age from 87 to 96 years. Fiatarone's goal was to improve the participants quality of the life by making them stronger, thereby increasing their functional capacity. The study concentrated on the relationship between leg muscle strength and how fast participants could walk, based on the premise that the weaker a person's legs are, the longer it will take them to walk 20 feet.

Once again the results were startling; changes to the muscle size using the CT scan indicated that the participants muscle strength almost tripled and the size of their thigh muscles grew by more than 10%.

Both research studies offer conclusive evidence that muscle mass and strength can be regained no matter what your age and no matter what the state of your body's musculature before you start your exercise program.

There are some handouts on Exercise and Ageing BWY Eastern Regions website: www.yoga-east.org

SUMMARY OF AGE RELATED CHANGES IN MUSCLES

Muscle loses size and strength as we get older. This is caused by a number of factors working in combination, including:   

•    Individual muscle fibres shrink in size.

•   The size and shape of muscles cells alter as we get older.

•   Muscle fibres reduce in number.

•   Lost muscle fibres are replaced by non-functioning fibrous tissue.

•   The energy ‘powerhouse’ within each muscle cell, called the mitochondria, reduces its output.

•   Enzyme changes within each muscle cell reduce the amount of available energy.

•  The nerve impulses that control muscle cells aren’t transmitted as efficiently.

•   The ratio of fast twitch/slow twitch muscles alter as we get older.