Physical function (ie, aerobic capacity, gait speed, and muscle strength) has been proposed as a biomarker of healthy ageing, as it is predictive of adverse health events, disability, and mortality. The role of physical exercise as a therapeutic strategy for prevention of both disease and the associated decline in functional capacity has been emphasised repeatedly. Supervised exercise interventions in hospitalised older people (aged ≥75 years) have been proved to be safe and effective in preventing or attenuating functional and cognitive decline. Unfortunately, few studies have explored the potential role of tailored physical activity guidelines to maximise exercise-related effect on function. Also, exercise has not been fully integrated into primary or geriatric medical practice and is almost absent from the core training of most medical doctors and other health-care providers. Physical trainers should be included in health-care systems to help manage physical exercise programmes for older patients. Taking into consideration current evidence about the benefits of exercise for frail older adults, it is unethical not to prescribe physical exercise for such individuals. To promote healthy and dignified ageing, it is therefore essential to help health-care systems to more efficiently implement evidence-based exercise programmes for frail older adults in all community and care settings.
This Personal View asserts that increased knowledge about the effects of exercise interventions to improve age-related intrinsic capacity domains and functional ability in people with frailty would enable an increasingly coherent and holistic approach to treating both fit and frail older (≥65 years) patients. We believe that the physiological justifications for using exercise treatments to increase muscle mass and reduce symptoms of frailty are an example of medical, scientific, and pharmaceutical industry failures to appreciate exercise's major role as a therapeutic agent to prevent and treat both disease and loss of functional capacity.
The World report on ageing and health: a policy framework for healthy ageing. Comparative approaches to understanding the relation between aging and physical function. A short physical performance battery assessing lower extremity function: association with self-reported disability and prediction of mortality and nursing home admission. Reference values for handgrip strength and their association with intrinsic capacity domains among older adults. Association of walking pace and handgrip strength with all-cause, cardiovascular, and cancer mortality: a UK Biobank observational study. Comparative relevance of physical fitness and adiposity on life expectancy: a UK Biobank observational study. Physical function and all-cause mortality in older adults diagnosed with cancer: a systematic review and meta-analysis. Gait speed as a mediator of the effect of sarcopenia on dependency in activities of daily living. Gait speed as a mediator of the effect of sarcopenia on dependency in activities of daily living. Rethinking the association of high blood pressure with mortality in elderly adults: the impact of frailty. Functional ability (defined as retention of autonomy that promotes wellbeing as people age), a term established by WHO in its first world report on ageing and health, is the cornerstone of healthy ageing. The interactions between an individual's intrinsic capacity (ie, their mental and physical capacity: cognition and mental health, sensory function, metabolic rate, mobility, and muscle strength) and their socioeconomic and physical environments are crucial in achieving the optimum trajectory to maintain a person's functional ability throughout their life course. Objective physical function tests have been proposed as reliable indicators of overall health and functional status, which is predictive of adverse health events and disability, and is strongly linked to all-cause mortality in older populations (aged ≥65 years) and to functional outcomes in clinical trials. Such tests include gait speed, used alone or in combination with other measures such as the Short Physical Performance Battery (a set of physical function tests including standing balance, normal gait speed, and timed sit-to-stand). In the same way, higher handgrip strength is associated with lower odds of adverse events in most of the intrinsic capacity domains, and with a lower rate of hospitalisation (in men) compared with their peers with a weaker handgrip after adjustment for disease burden. Thus, multimorbidity, including cardiovascular disease, might not be the most important factor modulating individual domains of intrinsic capacity that are responsible for functional decline and diminished ability to complete activities of daily living. Moreover, physical performance measures such as gait speed are not only powerful markers of longevity, but also appear to have a more important role in moderating cardiovascular mortality and all-cause mortality compared with other measures of physical activity or function. Thus, monitoring and preserving functional capacity in older adults is now a primary focus for clinicians in the management of cardiovascular diseases. Gait speed has been shown to play a mediating role in the adverse effect of sarcopenia (ie, decline in muscle mass and function) on functional dependence, after adjusting for age, sex, and body-mass index. Older adults who presented with characteristics of sarcopenia, but also had a faster gait speed than their fitter peers, showed better functional ability in activities of daily living than those peers, because gait speed mediates the relationship between sarcopenia and ability to complete activities of daily living. However, physical performance measures in mortality studies might have been biased by pre-existing illness (possibly through mechanisms other than decreased physical function related to illness or mortality), given that older participants who reported fast walking speed showed an association between higher systolic blood pressure and mortality, whereas there was no such association in slower walkers. For these reasons, physical function could be a simple and easily collected measure of overall physical health status.
Frailty is another important clinical syndrome used in geriatric medicine. It refers to a distinctive ageing-related health state in which multiple body systems gradually lose their innate capacity, resulting in decreased physiological reserves and resilience in the face of stressors. Physical inactivity is a key contributing factor for sarcopenia, which appears to be a key contributor to frailty. Over the past few years, frailty has attracted increased interest because of its direct relationship with adverse health outcomes such as physical and functional decline, hospitalisation, disability associated with institutionalisation, reduced quality of life, excess morbidity, and increased mortality. Accordingly, an important understanding about frailty is that, as with chronic diseases, the focus with older patients should be on functionality and not on the diagnosis of disease.
Recovery of activities of daily living in older adults after hospitalization for acute medical illness. Effect of exercise intervention on functional decline in very elderly patients during acute hospitalization: a randomized clinical trial. Inter-individual variability in response to exercise intervention or usual care in hospitalized older adults. Hospitalization-associated disability: “she was probably able to ambulate, but I'm not sure”. Effect of exercise intervention on functional decline in very elderly patients during acute hospitalization: a randomized clinical trial. Inter-individual variability in response to exercise intervention or usual care in hospitalized older adults. Assessing the impact of physical exercise on cognitive function in older medical patients during acute hospitalization: secondary analysis of a randomized trial. Recovery of the decline in activities of daily living after hospitalization through an individualized exercise programme: secondary analysis of a randomized clinical trial. Recovery of the decline in activities of daily living after hospitalization through an individualized exercise programme: secondary analysis of a randomized clinical trial. Inter-individual variability in response to exercise intervention or usual care in hospitalized older adults. Hospitalization-associated disability: “she was probably able to ambulate, but I'm not sure”. In older adults, particularly those who are prefrail and frail, hospitalisation is strongly linked to functional and cognitive decline, which in turn are associated with sustained disability, institutionalisation, and death. This decline in the ability to complete activities of daily living has been called hospital-associated disability, defined as the loss of ability to complete one or more activities of daily living, such as using the toilet, bathing, dressing, transferring from bed to chair, or walking independently following acute hospitalisation. In older people who are hospitalised, supervised exercise interventions have been proved safe and effective for attenuating functional decline and preventing cognitive decline. Physical function improvements are mediated by cognitive function enhancements, which highlights the essential role of cognition, specifically executive functions, for maintaining or promoting physical function (eg, balance, gait, and muscle strength) in older people, especially in the case of in-hospital exercise-training programmes. Similarly, it was reported that an individualised multicomponent exercise-training programme for older adults could reverse the loss of ability to complete activities of daily living (ie, toilet use, transfers, mobility, and stair climbing) that frequently occur during hospitalisation. This training-induced modification of the disability trajectory associated with hospitalisation was shown to be independent of changes in the inpatient's physical function as quantified by the Short Physical Performance Battery. Each patient, therefore, whatever their functional level, should receive an individualised prescription of exercise during hospitalisation. Thus, improving or maintaining function becomes the ultimate mission for the medical care of older people. Exercise should be considered as a leading treatment strategy to prevent the functional and cognitive decline in older people that are often associated with prolonged bed rest during hospitalisation. Indeed, it has been shown that the best strategy is to prevent functional decline in the first place, rather than trying to recover function after it has been lost.