fat achieved through resistive or aerobic training improve insulin resistance and complement dietary and pharmacological management of type 2 diabetes in the older adult with central obesity.22
Exercises designed to stimulate skeletal muscle hypertrophy in congestive heart failure provide benefits that counteract the catabolic effects of circulating cytokines in this disease and are not achievable with cardiac medications alone. Indeed, regular exercise induces antiatherogenic adaptations in vascular function and structure, irrespective of traditional cardiovascular disease (CVD) risk factors. Muscle‐derived myokines are responsible for many of the beneficial effects of exercise, particularly by promoting a healthy anti‐inflammatory milieu.21
Functional improvements in individuals with arthritis who are given lower‐extremity exercises include improved joint stability and may thus add to the benefits of anti‐inflammatory and analgesic medications. It is not possible in this chapter to review every disease in which exercise has beneficial effects, and therefore we will use type 2 diabetes as one example of the diseases outlined in Table 7.7.
Exercise in the treatment of type 2 diabetes
The prevalence of type 2 diabetes appears to be rising precipitously, linked to the rise in obesity throughout the world. Most of the individuals concerned have scope for lifestyle modification, particularly for suboptimal levels of physical activity. Cardiovascular disease accounts for half of the mortality in older adults with type 2 diabetes,150 emphasising the complex clinical syndrome represented by this cohort.
The value of tight regulation of glucose in adults with type 2 diabetes has been convincingly demonstrated in the UK Prospective Diabetes Study, among others.151,152 This is particularly relevant to older adults, who may have glucose intolerance and then diabetes for many decades and are therefore at extremely high risk for end organ damage due to glycosylation of body proteins. Although glycaemic control has been proven to be highly effective in controlling diabetes, the deleterious effects of central obesity and lack of exercise can undo the benefits of proper medical management and therefore may hasten the emergence of disease complications in susceptible individuals with insulin resistance. Insulin itself is associated with significant weight gain, thus exacerbating one of the underlying causes of the disease. Weight‐loss diets are clearly central to the management plan of obese individuals with type 2 diabetes and may be aided by the use of metformin as an appetite suppressant or acarbose to decrease the extent of carbohydrate absorption. However, the difficulty of long‐term weight management via dietary restriction is well known in the clinical setting due to various factors that impede such behavioural change in older adults. In addition, weight cycling due to repetitive attempts at sustained weight loss leads to losses of lean tissue (muscle and bone) and decreases in metabolic rate, thus worsening the energy balance equation in the end and making dietary management more and more difficult. Therefore, the standard care of type 2 diabetes leaves most individuals sub‐optimally managed in relation to their primary metabolic derangement: insensitivity to the action of insulin.
All consensus statements1,153 and position stands154 recommend aerobic exercise as part of the management plan in type 2 diabetes. Moderate‐ or high‐intensity aerobic exercise of 3–4 h per week results in improved insulin sensitivity and glucose homeostasis, assists in attaining or maintaining lower body weight, reduces visceral fat depots, modestly improves blood pressure and lipids, and lowers the risk of cardiovascular morbidity and mortality. However, the clinical management of the obese elderly patient with this disease is often complicated by increasing insulin resistance and resultant polypharmacy, in addition to multiple other comorbid health conditions that impede compliance with both diet and aerobic exercise and reduce quality of life.22 For example, it would not be unusual for an older adult with diabetes to present with obesity, osteoarthritis, ischaemic heart disease, hypertension, gout, hyperlipidaemia, peripheral vascular disease, sleep apnoea, peripheral neuropathy, a gait and balance disorder, functional impairment, renal disease, postural hypotension, bladder dysfunction, retinal disease, and depression. Such disease clustering makes the application of standard dietary and exercise recommendations in addition to intense pharmacological management a challenge to practitioner and patient alike. It is not surprising that aerobic exercise recommendations, endorsed by all international consensus statements,154 are often difficult or impossible to implement in such patients. In particular, obesity, osteoarthritis, amputations, visual impairment, foot problems, fall risk, orthostatic hypotension, peripheral vascular disease, and a low threshold for ischaemia may make aerobic exercise at the volumes and/or intensities shown to produce metabolic benefits in clinical trials unrealistic in practice.
Table 7.7 Exercise and disease treatment.
| Disease state | Exercise modality of choice | Considerations for the prescription |
|---|---|---|
| Arthritis | Aerobic Resistance training | Low impact. Sufficient volume to achieve a healthy weight if obese. |
| Chronic insomnia | Aerobic Resistance training | Time of day does not consistently influence efficacy. Effect is immediate. |
| Chronic obstructive pulmonary disease | Aerobic Resistance training | Resistance training may be more tolerable in severe disease; combined effects complementary if feasible. |
| Time exercise sessions to coincide with bronchodilator medication peak. Use oxygen during exercise as needed. | ||
| Chronic renal failure | Aerobic Resistance training | Exercise reduces cardiovascular and metabolic risk factors, improves depression. |
| Resistance training offsets myopathy of chronic renal failure. | ||
| Congestive heart failure | Aerobic Resistance training | Resistance training may be more tolerable if dyspnoea severely limits aerobic activity. |
| Cardiac cachexia is targeted by resistance training. | ||
| Coronary artery disease | Aerobic Resistance training | Complementary effects on exercise capacity and metabolic profile from combined exercise modalities. |
| Resistance training may be more tolerable if the ischaemic threshold is very low due to lower heart rate response to training. | ||
| Depression | Aerobic Resistance training | High‐intensity resistance training and adequate volumes of aerobic exercise are more efficacious than low‐intensity/low‐volume exercise in major depression. |
| Hypertension | Aerobic Resistance training | Small to moderate reduction in systolic and diastolic pressures is seen. |
| Larger changes are seen if weight loss occurs. | ||
| Obesity | Aerobic Resistance training | Sufficient energy expenditure to induce a deficit. |
| Resistance training but not aerobic exercise maintains lean tissue (muscle and bone) during dietary weight loss. | ||
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Osteoporosis
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