‘We do not stop exercising because we grow old – we grow old because we stop exercising.’ Kenneth Cooper, pioneer of aerobic exercise
Frailty in old age is a huge and growing problem, and the role of exercise in the prevention and treatment of frailty is one of the most important things I have to tell you about. This is an issue that affects all of us and decides the pattern not only of our futures but also of the social and financial health of the nation. The most important thing to understand is that frailty is not inevitable.
What is frailty?
Frailty has been defined as a ‘clinically recognisable state of increased vulnerability resulting from aging-associated decline in reserve and function across multiple physiologic systems such that the ability to cope with every day or acute stressors is compromised’! In brief, it means getting old and feeble. Frailty is the condition of general weakness and debility that is often seen as an inevitable consequence of the ageing process. Some of the essential features include low grip-strength, low energy, slowed walking speed, low physical activity, and/or unintentional weight loss.
Here is a test for frailty. Sit in an upright chair. Start your stopwatch, get up and walk 3 yards, turn round, return to your chair and sit down. A time of less than 10 seconds is normal, between 10 and 20 seconds is an indicator of encroaching frailty and more than 20 seconds is characteristic of frailty. Slightly more complicated is the five-repetition chair-rise test, which poses an increased risk of falling for those who take more than a minute to achieve the five up and downs. Walking speed is also an indicator of frailty – being capable of more than 13/4 mph rules out frailty; below 11/2 mph, the slower you are, the frailer you are likely to be. Among older people, those with a slow pace are three times more likely to need care than those who walk at faster speeds.
What causes frailty?
Frailty is closely allied to loss of muscle tissue. As we age we all lose muscle mass and strength, a condition called sarcopenia. A degree of age-related sarcopenia is unavoidable, but the rate at which we lose muscle is largely dependent on how much exercise we take. By the seventh and eighth decade of life, skeletal muscle strength is decreased, on average, by 20–40 per cent for both men and women. Most of this loss of strength is caused by decreased muscle mass. The resulting progressive loss of muscle power leads to increasing disability and loss of independence. The prevalence of sarcopenia increases with each five-year age group, from about 15 per cent among 65–70-year-olds to as much as 50 per cent in over-85s and probably becoming increasingly common thereafter. It accelerates with the passing of the years.
As the age of the population grows, so will the numbers with sarcopenia. The accelerated loss of aerobic capacity with advancing age has important clinical ramifications. The ability of older persons to function independently in the community depends largely on their maintaining sufficient aerobic capacity and muscle strength to perform daily activities. The perceived degree of effort and breathlessness of a given activity is determined by its oxygen cost relative to a person’s peak VO2. People who have lost muscle strength tend to avoid tasks they think will require a lot of effort, setting off a vicious circle of further reduction in aerobic capacity, causing further avoidance of physical activity and further loss of muscle mass and strength.’ This is what frailty is all about – and it is not an inevitable consequence of ageing but, at least in part, a lifestyle choice.
The English National Fitness Survey in 1994 highlighted the low level of fitness in the general population and the progressive further reduction with increasing age. Physical capacity becomes increasingly important as age increases. For 50-year-olds, not being as fit as they should be for that age will not make a substantial difference to their daily living (unless they are extremely unfit). But for an 80- or 90-year-old, poor fitness levels (relative to that age group) may mean that the individual is unable to maintain an independent life. The difference between being fit or unfit at this age means the difference between being able to get out of bed and dress unaided or relying on carers. Or the difference between being able to get up from a chair and put the kettle on or being dependent on others to do it for them. The level of VO2max (physical fitness) that predicts loss of independence has been calculated at about 18ml/min/kg for men and 15ml/kg/min for women. Personally, I believe that these figures are a deal higher than reflected by reality, but the point is well made that the lower your VO2max the less able you are to look after yourself. Old people are particularly liable to become dependent if they develop an age-related disease (e.g. osteoarthritis).
Frailty is usually the result of the accumulation of all the diseases discussed earlier – obesity, diabetes, heart disease, osteoporosis, osteoarthritis and general unfitness. All of these can be made much less likely by keeping physically active but failure to take exercise allows them to multiply with the inevitable outcome of weakness, unfitness and frailty in later life.
Frailty is avoidable!!!