One of the best decisions I have made was to start exercising at a young age. The next best decision was to include resistance training. The evidence to support the benefits of physical activity on both physical and mental health are outstanding, however, this research only began in the latter part of the 20th Century.
Early Research of Physical Activity
The focus of early research was that of the effects of a sedentary lifestyle on coronary heart disease (CHD). Much of the early research involved self-reporting of leisure time physical activity, making it difficult to determine health benefits in terms of frequency, intensity, time and type (FITT). Cardiorespiratory fitness became the objective to determine improved health outcomes for CHD.
Since 2000, overall health promotion has been highlighted but what does this mean in terms of ageing?
An Ageing Population
According to the Australian Bureau of Statistics (ABS) (2003), 18% of our population will be over 65 years of age by 2020, compared to 13% in 2001. Since 1995, the participation rates of physical activity for those over 65 years of age had declined slightly. (ABS, 2006) The introduction of a higher retiring age could be responsible for a more sedentary lifestyle. In other words, we are living longer but with more associated health problems. These include bowel cancer, Type II diabetes, ischaemic heart disease and stroke.
The focus of health promotion and physical activity in older adults is to improve the quality of life, both at an individual level and at an economic level. The potential positive outcomes are:
- Delayed Disease
- Improved Immunity
- Increased Endurance
- Increased Strength
- Improved Social Interaction
- Improved Functional Movement
- Increased Self Worth
- Enhanced Cognitive Function
- Reduced Expenditure (individual and as a society)
Loss of Lean Muscle Mass and Ageing
The most prominent sign of ageing is a loss of muscle mass known as sarcopenia. In a young adult, lean muscle mass accounts for about 50% of body weight. This can decrease to about 25% by the age of 75. This has negative consequences at a mechanical/functional level as well as chronic diseases. Improving mobility may decrease the risk of falls. Joint stability is weakened as surrounding muscle tissue deteriorates. Research also shows that osteoporosis or loss of bone density is also proportional to the loss of muscle fibres.
Metabolic rate also decreases with the loss of muscle mass by approximately 30% between the ages of 20 and 70. The combined effect of sarcopenia, a less efficient metabolism and lowered anabolic hormone levels leads to a decreased ability to burn fat as well.
So a decrease in muscle mass is offset by an increase in body fat. Obesity, high cholesterol and high blood pressure often result. Research shows that for both men and women over 60, those with significant muscle loss and increased body fat, there is a significantly increased risk of having three or more physical disabilities than those with either sarcopenia or obesity alone (1).
The diagram below shows the relationship between all these factors.
A decrease in muscle mass may also lead to an increase in blood sugar levels. Less surface area of lean muscle tissue provides less surface area for glucose transport from the blood and increased resistance to insulin.
A cycle is created and may result in an acceleration of muscle loss and resulting in Type II diabetes.
Resistance training, in combination with good nutrition, is the perfect answer for increasing and maintaining muscle mass and strength by increasing protein synthesis. Be increasing muscle mass, you can expect a simultaneous lowering of blood sugar levels and a decrease in insulin resistance as well. Metabolic rate increases resulting in more efficient oxidisation of fats. Ligaments and joints are in turn better supported and the stress on bone tissue increases bone density.
77-year-old Ernestine Shepherd is the world’s oldest female bodybuilder
In essence, resistance training has the potential to reverse the effects of ageing on many levels.
Research has found that performing 8-10 exercises, at least twice a week, consisting of 1-2 sets of 10-15 repetitions, can increase muscle mass by 1% per week of resistance training in older adults who were once sedentary. (Nelson et al., 2007)
The positive effects of strengthening the body physically for older adults are many.
Increased confidence in performing daily tasks improves, as does self-esteem. Being physically strong improves social interaction, as they are able to participate in activities that they may not otherwise have been physically able to if not exercising.
Cognitive function also improves as certain brain areas are involved in the process of performing physical activity and there is much evidence to support the prevention and/or delay of the onset of dementia. (Laurin et al, 2001).
Being physically active has been a part of my life since my teens. Throughout my pregnancies and child rearing, I allowed time for my exercise, incorporating it in my day either with my children or having some time to myself. This has taught my children to look after their bodies and appreciate the value of physical activity. They have played representative soccer, hold records in various school sports and now that they are young adults they also include keeping physically active in their lives. I am now in my 50’s and enjoy sharing with my son the love of resistance training. We discuss our programs, he watches me compete and loves it that his mum ‘lifts’.
As we can see, the benefits of physical activity are many and varied and the ultimate aim of any form of exercise program should be overall health, not merely aesthetic benefits. As we age, physical activity and especially maintenance of muscle mass play an important role in improving, maintaining health and even preventing many chronic diseases that can rob individuals of the quality of life.
It is never too late to start.