for People with Chronic Conditions

CHAPTER TWELVE Exercise for People with Chronic Conditions

This chapter considers common chronic conditions which will be encountered by the physiotherapist. Physiotherapists should be aware of the impact of these conditions on exercise ability, the benefits of exercise and special considerations for prescribing exercise in these conditions. Patients with one of these chronic conditions may present for physiotherapy treatment to manage the condition itself, or the chronic condition may be a co-morbidity which requires consideration when prescribing exercise.

In view of the current healthcare priorities this chapter also considers exercise prescription for patients who are referred for exercise programmes to reduce the risk factors associated with the development and progression of some chronic conditions.

EXERCISE FOR PEOPLE WITH OBESITY

Obesity is defined as an accumulation of excess fat to the extent that it has a negative effect on health and is often quantified using the measurement of body mass index (BMI). The World Health Organization defines a BMI of >25 as overweight, and a BMI of >30 as obese.

This section will discuss the role of exercise in the prevention and management of obesity, as well as considerations for exercise in the obese population.

Benefits of exercise for obesity prevention and management

Obesity is caused when more energy is consumed than expended. There are many factors contributing to the cause of obesity; however obesity tends to occur after several years of inactivity as physical activity plays an important part in maintaining the amount of energy expended. Physical activity levels often decline from childhood to adult life; however there is not usually an accompanying decline in energy intake through the diet – this leads to a gradual increase in body weight.

Obesity can lead to many other health problems, most notably non-insulin-dependent (type 2) diabetes, cardiovascular disease and some types of cancer; therefore any intervention that can manage obesity is important for health.

In terms of exercise, the management of obesity can be approached from two perspectives: exercise for health and exercise for weight loss.

Regular physical activity reduces many of the health risks associated with obesity regardless of weight loss. Active obese individuals have lower morbidity and mortality than normal weight individuals who are sedentary; it appears that cardiorespiratory fitness is an important predictor of morbidity in obese individuals. Therefore it is important to educate people that regular exercise has health benefits in the absence of weight loss.

The management of weight loss tends to focus primarily on diet, and exercise is often recommended as a secondary activity. This may be due to the fact that exercise alone produces a somewhat modest weight loss of 0.5–1.0 kg per month; however implementation of an exercise programme and dietary intervention together have been demonstrated to produce greater weight loss than either intervention alone. Exercise in combination with diet affects the body composition by producing a greater loss of body fat and conservation of muscle. The inclusion of exercise is important for long-term weight loss, as diet in combination with exercise has been shown to produce long-term weight loss in comparison with diet alone.

When prescribing an exercise programme it should be remembered that individuals have differing responses to exercise for weight loss. This is thought to be due to genetic make up and gender – whereby men lose more weight in response to exercise than women.

In the guidelines below ‘physical activity’ can be exchanged for ‘exercise,’ as exercise to prevent obesity and/or to maintain long-term weight loss needs to be incorporated into the person’s lifestyle and carried out on an ongoing basis. Although some people do get into the habit of attending a gym on a regular basis many people will not, and adapting their daily routine to include such activities as walking to work or taking the stairs may be more effective than a formal exercise programme.

Special considerations for exercise in people with obesity

If the person has been sedentary for some time the exercise programme will need to be staged to produce a gentle increase in duration.

Before embarking on an exercise programme the person should be screened for co-morbidities that may have an influence on the exercise prescription, such as diabetes or cardiac conditions.

High-impact activities such as jogging should be avoided due to the excessive strain that is placed through the joints.

Before using exercise equipment with morbidly obese people the individual’s weight should be checked against the maximum weight limit of the equipment to ensure safe use.

Fluid balance is not well regulated in people who are overweight and they are more susceptible to dehydration; therefore they should be advised to drink regularly.

Temperature regulation is also affected in obesity, and people should be advised to wear light clothing and exercise in a cool environment.

Recommended exercise prescription

Exercise in the management of obesity

EXERCISE FOR PEOPLE WITH DIABETES

This section will discuss the role of exercise in the prevention and management of types 1 and 2 diabetes and consider the effect of exercise on the control of diabetes.

The impact of non-insulin-dependent (type 2) diabetes on exercise ability

Exercise increases insulin sensitivity and helps with glycaemic control. Glucose levels drop during moderate-intensity exercise, as during activity there is a decrease in glucose production at the liver. The amount of change in glucose level varies with the intensity and duration of exercise. When people with obesity perform a period of short-term intense exercise, glucose levels often rise during the exercise and remain raised for an hour afterwards. The increases in insulin sensitivity following a single bout of exercise are relatively short-lived; therefore regular exercise is recommended.

The benefits of exercise in non-insulin-dependent (type 2) diabetes

Type 2 diabetes is defined as a combination of insulin resistance and insulin deficiency and is caused by a combination of factors. Insulin resistance is manifested as a decreased amount of glycogen stored in the liver and muscle, and decreased insulin transport and receptor substrate in the muscle restricting the amount of phosphorylation that can occur. The insulin deficiency is due to abnormal secretion of insulin and reduced secretion of insulin due to hyperglycaemia.

Type 2 diabetes can lead to the development of many co-morbid conditions, such as cardiovascular disease, neuropathy, cerebrovascular disease and susceptibility to infection. There appears to be a genetic tendency to develop the disease and other factors such as older age, ethnicity and obesity are also linked to developing diabetes.

If normal blood glucose levels can be maintained, then the onset of these conditions can be delayed.

Exercise increases insulin sensitivity and helps with glycaemic control. Glucose levels drop during moderate-intensity exercise, as during activity there is a decrease in glucose production at the liver. The amount of change in glucose level varies with the intensity and duration of exercise. When people with obesity perform a period of short-term intense exercise, glucose levels often rise during the exercise and remain raised and for an hour afterwards. The increase in insulin sensitivity following a single bout of exercise is relatively short-lived; therefore regular exercise is recommended.

Special considerations for exercise in people with type 2 diabetes

Regular exercise at low to moderate intensity is recommended to increase insulin sensitivity and lower glucose levels.

If insulin dependent, it may be preferable to exercise on a daily basis to allow a regular and stable insulin dosage to be established.

Although additional cardiovascular fitness may be achieved by working at higher intensity, the low to moderate level recommended optimizes the risk/benefit balance for people with type 2 diabetes.

Heart rate may not be a suitable means of monitoring exercise intensity in this group as development of autonomic neuropathy will affect the heart rate (HR) response to exercise.

Patients with complications such as peripheral neuropathy may require modified exercises so that they can be safely performed without causing themselves injury.

In people with advanced stages of cardiovascular or retinal complications resistance exercises should be modified to reduce the weight lifted, reduce the number of repetitions to avoid exhaustion and limit the amount of sustained grip time to prevent an untoward increase in systemic blood pressure.

Recommended exercise prescription

Resistance training

Although there is little direct evidence for the use of resistance training in type 2 diabetes it is thought to produce similar benefits in maintaining fat-free mass, increasing muscle strength and endurance and reducing glucose levels and insulin resistance as seen in the non-diabetic population. It is recommended that a minimum of 8–10 resistance exercises involving the major muscle groups should be performed as part of an exercise programme.

Frequency: At least 2 days a week.

Repetitions: A minimum of one set of 10–15 repetitions to near fatigue.

The impact of type 1 diabetes on exercise ability

In type 1 diabetes the pancreas does not produce insulin, which must be replaced by injections of insulin to regulate blood glucose levels. The response to exercise in people with type 1 diabetes needs to be understood so that a physiotherapist prescribing exercise to manage a co-morbid condition can take them into consideration. In addition people with type 1 diabetes may wish to take part in sports and exercise for pleasure or at a competitive level.

Blood glucose levels tend to decrease during and after aerobic exercise in people with type 1 diabetes; there are several factors which contribute to this. During aerobic activity there is an increase in the rate of absorption of subcutaneously injected insulin due to the increase in circulation. In addition the increase in body temperature produced during exercise leads to an increase in the rate of insulin absorption. Plasma levels of insulin do not decrease during exercise; therefore any insulin injected prior to exercise will remain present and impair glucose production. Exercise produces an increase in the insulin sensitivity of skeletal muscles, which may be sustained for several hours. Finally there is an increase in glucose uptake through non-insulin-mediated pathways, which leads to a decrease in insulin requirement. This produces an imbalance between glucose depletion and insulin levels, resulting in low blood glucose levels. If a person has repeated hypoglycaemic episodes, then the counter-regulation of insulin response becomes dampened, which makes a person who has been experiencing hypoglycaemia more prone to further episodes.

The combination of the factors above may lead the person to become hypoglycaemic both during and for several hours after the exercise. As hypoglycaemia can be fatal in extreme cases it is vital that both the physiotherapist and the person with diabetes are aware of the signs and symptoms of hypoglycaemia.

High-intensity, short-burst, anaerobic exercise in people with type 1 diabetes tends to cause blood glucose levels to rise, as it stimulates over-production of glucose from the liver and impairs glucose utilization. Blood glucose levels often stay raised for some time. The resulting hyperglycaemia and ketoacidosis leads to dehydration and an increase in the acidity of the blood, both of which can impair exercise performance.

These effects are seen at an exercise intensity of over 75% of maximum heart rate.

The benefits of exercise in people with type 1 (insulin-dependent) diabetes

There is no evidence to support the recommendation of exercise to improve the control of blood glucose levels in people with type 1 diabetes. People with type 1 diabetes are, however, at a much increased risk of cardiovascular disease, and regular exercise can reduce the risk of developing cardiovascular disease in this group as in any other population.

Consideration for exercise prescription in type 1 diabetes

As with type 2 diabetes.

Prevention and management of hypoglycaemia: particular attention to monitoring blood glucose before, during and for several hours after exercising should be given when establishing an exercise programme. It may be necessary to reduce the insulin dose or increase the intake of carbohydrates before exercise, which should be done in proportion to the intensity of the exercise to be undertaken.

Ensure that there is an immediate source of sugar to hand. Fruit juice or glucose tablets are recommended, and anyone with type 1 diabetes should carry these sugar sources with them when exercising.

Be aware of the signs and symptoms of hypoglycaemia in the early stages of diabetes:

excessive sweating

Be aware of the signs and symptoms of hypoglycaemia in the later stages of diabetes:

slow speech/movement

Prevention and management of hyperglycaemia: blood glucose should be monitored before and for some period after high-intensity exercise.

If blood glucose levels are found to be high then supplementary insulin may be required.

Be aware of the high incidence of cardiovascular disease in this population and ensure that any cardiac conditions are stable before exercising.

Recommended exercise prescription

For guidelines for exercise for health see type 2 diabetes.

EXERCISE FOR PEOPLE WITH CARDIOVASCULAR DISEASE

Cardiovascular diseases are the most common type of diseases which affect the population of the United Kingdom. These diseases include coronary heart disease, angina and myocardial infarction, heart failure and hypertension. As these diseases are so common, physiotherapists will come across patients suffering from these types of disorder either as a primary reason for referral for treatment, for example to a cardiac rehabilitation class, or as a co-morbidity when a patient has been referred for treatment for another condition, for example back pain. Much has been written about exercise in relation to people with cardiovascular disease and so this section of the chapter will give only a broad overview of this area to allow the physiotherapist to safely prescribe exercise to patients with cardiovascular disease.

The impact of cardiovascular disease on exercise ability

People with cardiovascular disease may suffer from a variety of symptoms depending on the nature and severity of their disease. Symptoms can include angina, dyspnoea and fatigue, all of which can cause discomfort whilst exercising and so reduce the patient’s activity levels. Patients can become fearful of exercising because of bringing on symptoms and this can lead to a decrease in activity and further reduction in exercise tolerance. If this process is left unchecked, the reduction in exercise tolerance will start to affect the patient’s ability to carry out normal daily activities. Physical inactivity is also a major risk factor in the development of coronary heart disease.

Benefits of exercise in cardiovascular disease

There is a large evidence base to support the therapeutic benefits of exercise in those with cardiovascular disease. These include reductions in symptoms and cardiovascular mortality and improvements in exercise tolerance and well-being. Most research in this group has been carried out using aerobic or endurance training. As a result, cardiac rehabilitation programmes are offered to those with coronary heart disease and controlled, chronic heart failure. Exercise is the cornerstone of these programmes but they also include an education component.

There is a large amount of evidence which supports using exercise to reduce the risk of onset of cardiovascular disease. Those who participate in exercise regularly reduce their risk of suffering from coronary heart disease and hypertension.

Cardiovascular training

This has been specifically shown to affect both central and peripheral physiology. Centrally an increase in myocardial perfusion and a decrease in myocardial oxygen consumption at a sub-maximal workload have been shown. This will lead to a reduction in heart rate and systolic blood pressure at sub-maximal workload. An increase in end diastolic volume and subsequent increase in stroke volume have also been shown. VO₂ peak improves during exercise and there is a reduction in resting blood pressure. Peripherally an increase in capillary beds and mitochondrial enzymes in muscles allows more efficient use of oxygen during exercise. The changes seen will be subject to the frequency, intensity and duration of exercise. This in turn will be affected by the severity of the patient’s symptoms, due to their cardiovascular disease. These patients will be limited maximally by their cardiovascular symptoms.

Cardiovascular training also confers benefit on blood cholesterol levels. Raised blood cholesterol is another risk factor for the development of coronary artery disease. Regular exercise has been shown to increase levels of high-density lipo protein (HDL) cholesterol and reduce triglycerides and low-density lipo protein (LDL) cholesterol. Coronary artery disease is associated with raised levels of triglyceride and LDL cholesterol, which deposits on the endothelial wall of the arteries. HDL cholesterol is thought to move cholesterol away from the arterial wall to the liver, where it is catabolized.

Psychological benefits including an enhanced sense of well-being, reduced anxiety and improvement in self-confidence have been shown in people with cardiovascular disease who have undergone a cardiac rehabilitation programme.

Resistance training

As resistance training is associated with increases in blood pressure and the possibility of straining manoeuvres if an incorrect technique is used, it has not been used as widely as aerobic training for those with cardiovascular disease. More recently resistance training, using moderate loads, has been used safely in cardiac rehabilitation programmes for those with normal left ventricular function and good cardiorespiratory fitness. Improvements in muscle strength will help with functional activities such as carrying shopping. Resistance training should not be used for high-risk patients with coronary artery disease or those with severe hypertension. Resistance training to fatigue is not recommended for high-risk patients. Fatigue should be kept to a moderate level (Borg scale < 15). Little research has been carried out to support the use of resistance training in those with chronic heart failure and current recommendations suggest using aerobic exercise only in this group.

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Tags: The Physiotherapists Pocket Guide to Exercise Assessment

Nov 7, 2016 | Posted by admin in MANUAL THERAPIST | Comments Off

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