Exercise as therapy

Published on 16/03/2015 by admin

Last modified 22/04/2025

Print this page

This article have been viewed 1285 times

chapter 9 Exercise as therapy

INTRODUCTION

Exercise science is a large and growing body of knowledge about the acute and chronic effects of physical activity on health, structure and function. A Medline search for ‘exercise’ in the title returns 57,000 scientific journal articles. This discipline has truly come of age and is a key component of any integrative approach to patient care.

EXERCISE DEFINED

Physical exercise involves the voluntary movement of the body, incorporating large muscle groups, with the goal of enjoyment, relaxation and physical exertion to improve the body’s structure and function. The different types of exercise will be discussed shortly, but the avenues for exercise include sport participation, recreational activities such as bushwalking, fitness training such as resistance training, aerobic classes, yoga, Pilates, occupational and recreational work such as gardening, and incidental exercise such as walking to the shops or cycling to work.

WHY IS EXERCISE ESSENTIAL FOR HEALTH?

The renowned exercise biologist, Professor Frank Booth, described in great detail the importance of exercise for maintaining normal function and health, in his extensive review of the research literature.¹ The basic tenet is that the human genome has not changed appreciably in the past 45,000 years and developed in an environment of high levels of physical activity. While our lifestyles have become predominantly sedentary in our working and leisure environments, our underlying biology expects stimuli involving physical work for extended periods, possibly dawn until dusk, as well as high-force and high-power activities such as would have been required to carry water, children, food, construction materials and tools as well as to run after animals that we sought to kill, or run away from animals desiring to eat us.

Contemporary humans are flying in the face of our genome, which dictates every biochemical process in our bodies. The result is progressive disease and disability from early adulthood, or even earlier in the case of sedentary and often overweight children. Our physical health, apart from injury or infection, is dictated by four interacting factors: genetic predisposition, physical activity, nutritional intake, and environmental factors such as toxins and sun exposure.

Chronic disease is now being described as an epidemic currently accounting for some 70% of our total health burden. This is being driven principally by the three most significant risk factors for chronic disease: tobacco use, inappropriate nutrition and physical inactivity.

EXERCISE TRENDS IN AUSTRALIA AND ELSEWHERE

Despite the strong research evidence indicating that regular physical exercise is essential for human health, rates of sedentary and low exercise levels in Australia remain very high, at around 70% of the population over 15 years of age.² This has not changed appreciably in the past 10 years despite the best efforts of government and organisations such as the Cancer Council and Heart Foundation to address this societal problem. The rate of no or low physical exercise is higher in females (73%) than in males (66%), and higher in the oldest age group of 75 years and over, at 83%. The rate is lowest in people aged 15–24 years but still frighteningly high at 62%.

The 2007 Australian National Children’s Nutrition and Physical Activity Survey is one of the most extensive investigations of exercise patterns in children aged 2–16 years conducted to date, with some 4487 participants. It was encouraging that most children aged 9–16 years met the Department of Health and Ageing recommendation that children aged 5–18 years accumulate at least 60 minutes, and up to several hours, of moderate to vigorous physical activity every day. According to the survey, there was a 69% chance that any given child would achieve this recommendation. With regard to gender, girls met the guidelines less frequently than boys, both boys and girls were less likely to meet the requirement as they got older, and this drop-off was much higher in older girls.³

Internationally the data are similar for the developed nations; however, physical inactivity levels appear to be increasing markedly in developing countries with modernisation. One trend that is clear throughout the world is the increasing use of screen-based technologies such as television, computers and mobile phones, which appears to have the direct effect of reducing physical activity.

GENERAL HEALTH, QUALITY OF LIFE AND LONGEVITY

The application of exercise for prevention and management of some specific health problems will be described later in this chapter. To establish the importance of exercise for general health, quality and quantity of life, the overall effects of exercise are summarised in Table 9.1.

TABLE 9.1 Effects of regular exercise on health

Health parameter	Effect of regular exercise	Preferred exercise mode
Hypertension	Reduction of systolic and diastolic blood pressure	Aerobic predominantly but some research indicates anabolic also effective
Cardiac function	Increased stroke volume and maximum cardiac output	Aerobic exercise
Cardiorespiratory fitness	Increased efficiency and maximum capacity	Aerobic exercise
Haemoglobin	Increased	Aerobic exercise
Cholesterol	Reduces LDL, elevates HDL, lowers total cholesterol and triglycerides	Aerobic exercise
Glucose metabolism	Glucose tolerance and insulin sensitivity improved	Aerobic and anabolic exercise
Bone density	Increased bone mineral density, bone mineral content, cortical thickness and fracture threshold	Anabolic and ground-based impact exercises (e.g. skipping, bounding, jumping)
Body fat	Reduced percentage body fat	Aerobic and anabolic combined
Muscle mass	Increased muscle cross-sectional area, increased fibre size	Anabolic exercise
Strength	Increased	Anabolic exercise
Physical functioning	Gait speed, stair climb, sit to stand, balance, falls risk all improved	Anabolic and aerobic exercise
Quality of life	Improvement in both general and disease-specific QOL measures	Anabolic and aerobic exercise

HDL: high-density lipoprotein; LDL: low-density lipoprotein; QOL: quality of life.

With such beneficial effects one would expect active people to live longer and better-quality lives, and this is certainly borne out in the research.

TYPES OF EXERCISE

AEROBIC EXERCISE

Cardiorespiratory capacity or fitness relates to the ability to perform large-muscle-group, dynamic, moderate-to-high intensity exercise such as walking or cycling for prolonged periods.⁴ Exercise prescription for cardiovascular fitness is based on mode, intensity, duration and frequency of the activity. The activities prescribed most frequently are walking, cycling, jogging, running, rowing, swimming and hiking. It is suggested that individuals should choose activities that they enjoy and are enthusiastic about continuing, as this will increase program compliance.

ANABOLIC EXERCISE

The other major form of exercise critical to long-term health is anabolic exercise, which is also termed ‘resistance training’ or ‘weightlifting’. This form of exercise involves performing movements against resistance such as barbells, dumbbells, resistance machines or elastic resistance, such that the number of repetitions that can be completed is limited to 12 or less. This is a very important stipulation of intensity. If the movement can be completed more than 10–12 times then the resistance is too light and must be increased. Without such resistance the positive anabolic effects on muscle and bone will not be realised and the hormonal changes that are so neuro-protective will not result.

This concept may seem a little ‘out there’ for people who have not exercised previously or even lifted weights before but the research evidence in support of regular anabolic exercise is huge, demonstrating marked improvements in muscle mass, bone strength, functional capacity and positive effects on mental health and cognitive function. The recommendation of the American College of Sports Medicine is for people aged over 65 years to complete resistance training two to three times per week. The precise prescription is presented in Boxes 9.1 and 9.2.

BOX 9.1 Physical activity guidelines for healthy adults over 65 years, or those aged 50–64 with chronic conditions

Do moderately intense aerobic exercise 30 minutes a day, 5 days a week

Do vigorously intense aerobic exercise 20 minutes a day, 3 days a week

and

Do 8–10 strength-training exercises, 10–15 repetitions of each exercise 2–3 times per week

and

If you are at risk of falling, perform balance exercises

and

Have a physical activity plan

Source: Nelson et al 2006⁵

BOX 9.2 Physical activity guidelines for healthy adults under 65 years

Do moderately intense cardio 30 minutes a day, 5 days a week

Do vigorously intense cardio 20 minutes a day, 3 days a week

and

Do 8–10 strength-training exercises, 8–12 repetitions of each exercise, twice a week

Source: Haskell et al 2007⁶

For healthy adults over age 65 or adults aged 50–64 with chronic conditions, the physical activity guidelines in Box 9.1 are recommended.

FLEXIBILITY EXERCISE

Maintaining range of motion about our joints is also critical at all stages of life, and even more so as we age. Flexibility training involves taking the joints to a position which places the muscles on stretch—that is, they are at or near their maximal length. Holding the muscle at this stretched position when repeated over time causes the muscle to grow longer, which increases its length and results in increased joint range of motion.

MODE AND DOSAGE

The American College of Sports Medicine and the American Heart Association released a combined position stand in 2007. The recommendation on physical activity for healthy adults under 65 years of age is shown in Box 9.2.

ACCUMULATION OF EXERCISE IS THE KEY

One of the most common excuses people provide for their low level of physical activity is that they simply do not have the time. As can be seen in Boxes 9.1 and 9.2, the total commitment required is only 150 minutes of aerobic exercise per week and 90 minutes of strength training. This is less than 4% of a person’s total waking minutes per week. The key is to be flexible in how this is scheduled. Exercise can be undertaken at any time of day or night, and organised into any preferred blocks of effort, with little decrement in health benefit. So whether the patient completes a single bout of 30 minutes of aerobic exercise in a given day or three blocks of 10 minutes, the effect is essentially the same.

INCIDENTAL EXERCISE

While structured exercise sessions are very important in assisting people to meet the minimum recommended physical activity guidelines and in ensuring that all aspects of exercise modes are addressed, the importance of physical activity accumulated during a normal day should also be recognised. Such physical activity is termed ‘incidental exercise’ and recent research has demonstrated considerable benefit for weight control and diabetes management. The overall goal is to accumulate as many minutes each day of non-sedentary time and in particular to reduce the time spent sitting. Importantly, recent research indicates that increasing the time spent standing rather than sitting increases the overall energy usage through the day. Another effective strategy to increase physical activity is to take 5–10 minutes break each hour, stand up and take a walk. This provides benefit by increasing metabolic rate, and work efficiency will probably be improved overall.

There are a myriad ways to increase one’s incidental exercise each day. For example, instead of desperately trying to find a car park close to the bank or shopping centre, park a couple of hundred metres away and walk. Take the stairs instead of the lift or escalator. Walk to your next meeting if it is only down the road, rather than driving or catching a taxi.

GETTING STARTED

The first step on any great journey is often the hardest, and initiating an exercise program can also be daunting. If a person has never been involved in an ongoing exercise program, how to begin, what to expect, whether one is overdoing it or not working hard enough, are all questions the new exerciser faces. For many of us the experience of our bodies responding to exercise with increased heart rate, increased breathing, body temperature rising, muscles aching and the discomfort that can accompany exercise, is foreign and unsettling. For the vast majority these experiences are not harbingers of illness or death. They are the normal adjustments that the body makes automatically to help us perform exercise. Of course if the discomfort is excessive then this is a warning sign, and the person experiencing it should consult their doctor or exercise specialist. Habitual exercisers come to enjoy these changes in their physiology—the sweat, heat and exertion—because they are often associated with positive changes in the brain chemistry and a feeling of exhilaration and success.

If the patient is over 35 years of age or has any primary risk factors for cardiovascular disease such as a family history of heart attack or stroke, high blood pressure, high cholesterol or existing cardiovascular disease, or is overweight, then it is important that they consult their doctor before starting an exercise program.

To begin, it is a good idea to consider seeking expert advice or joining a supervised exercise program. Some insurers provide limited cover for visits to many of these professionals and programs. General practitioners can provide referral to an exercise physiologist as these are the recognised allied health professional for the prescription and monitoring of exercise programs, particularly for people with existing chronic disease.

No matter which option the patients selects, if it has been a while since they have been active it is important to start slowly. Find a routine that suits them. If the person enjoys the activity they are much more likely to stick with it. Whenever possible they should exercise with a friend or relative. Many people find the social aspects of exercise the most enjoyable, and having someone else along also increases safety.

EXERCISE EQUIPMENT

Physical activity, or exercise, does not need expensive equipment. Exercise equipment is big business but it is not necessary to have all the latest gear.

Appropriate shoes are vital and help prevent injury. A podiatrist or reputable shoe shop can help the patient select the right shoes. It is also important that they wear flexible, comfortable clothes, such as shorts and a t-shirt, when exercising. If heat or cold are significant factors then clothing should be adjusted accordingly.

Other equipment, such as heart rate monitors and home-gym systems, can certainly be useful, but are definitely not necessary. Most exercises can be done without the need for any additional equipment.

SELECTING AN EXERCISE PROGRAM

There are many ways to be physically active without too much cost or inconvenience. A person might choose to exercise at home or they might prefer the structure and safety of a supervised exercise program. For many people the best option is a mix of exercising at home and a supervised exercise program.

If the patient chooses a supervised exercise program, ask about the level and quality of the supervision provided. Look for a program run by a qualified exercise physiologist. If it is convenient for the patient to exercise in a fitness centre or community facility, try to contact a local exercise physiologist to assess the patient’s level of risk and design an exercise program specifically for them.

Wherever the patient chooses to be physically active, it is important that the GP and the patient consider comfort, health and safety.

WHO TO TALK TO

Exercise physiologists are healthcare professionals specifically trained to give advice on exercise. An exercise physiologist will work with the patient and/or the doctor to ensure an appropriate exercise prescription. Many structured exercise programs will require the patient to seek a medical clearance before starting, and this is advisable.

Before taking part in any exercise program, particularly if the patient has been diagnosed with a chronic illness, it is important for the patient’s GP to discuss the exercise plan with the exercise physiologist. The GP should ensure that they convey any concerns and advise on additional precautions.

WHAT IS A PHYSIOTHERAPIST?

Physiotherapists are trained to assess the underlying causes of joint, muscle and nerve injuries and provide treatment to ensure that people can resume their normal lifestyle as soon as possible.

WHAT IS AN EXERCISE PHYSIOLOGIST?

An exercise physiologist specialises in the delivery of exercise, lifestyle and behavioural modification programs for the prevention and management of chronic diseases. Exercise physiologists are the most appropriate allied healthcare professionals for:

• exercise prescription and management

• prevention and wellness

• secondary management of chronic disease.

Many medical insurers and government-funded programs around the world include exercise physiologists and may require referral from the GP to the exercise physiologist for the patient to receive a medical insurance rebate, depending on the particular nationalised insurance system. Most private health insurers now cover exercise physiologist services.

COMPONENTS OF AN EXERCISE SESSION

Warm-up

Warm-up facilitates the transition from rest to exercise; it may reduce susceptibility to musculoskeletal injury by improving joint range of motion, and reduce the risk of adverse cardiovascular events.⁴ Regardless of training mode, exercise sessions should start with 5–10 minutes of low-intensity exercise incorporating stretching exercises and/or progressive lower-intensity aerobic activity. For example, participants who use 20 kg in a chest press exercise for 12 repetitions might have a warm-up set using 5–10 kg for 15 repetitions before initiating this particular exercise. Similarly, participants who use brisk walking or jogging might conduct a warm-up phase using a slow walk before initiating the training program. Implementing a gradual transition from rest to intense exercise is critical in reducing the risk of an adverse event, such as muscle strain or even a cardiovascular event. The body is much more comfortable with gradual changes in exercise intensity.

Specific phase

Cardiorespiratory training includes 20–60 minutes of continuous or intermittent (minimum of 10-minute bouts accumulated during the day) of aerobic activity training at 60–90% maximum heart rate (MHR) or 50–85% MHR reserve.⁷ Anabolic resistance exercises include performing 1–4 sets per muscle group training at 50–80% of 1 RM (repetition maximum) or 6–12 RM.⁷ Flexibility or range-of-motion training includes performing 2–4 sets per muscle group at 30–60 seconds stretching time.⁷

Exercise order

The ordering of anabolic exercises should generally follow these rules:

• large muscle groups first (e.g. legs)

• multi-joint exercises (e.g. bench press) before single-joint (e.g. elbow extension)

• abdominal and lower-back exercises after whole-body ground-based exercises such as squat, dead lift, bench press and so on.

This is to avoid pre-fatiguing the muscle groups that stabilise and support the trunk. However, it is also important not to program abdominal and lower-back exercises last, as the person may often be getting tired or bored and drop them from the program. These exercises are very important for posture and protecting the lower back and so must be completed during each session.

Cool-down

This phase provides a gradual recovery from the specific activity performed and includes exercises using lower intensities. For example, participants can use slow walking when completing higher-intensity aerobic activity or lower-intensity stretching when completing a resistance training session. The cool-down allows appropriate circulatory adjustment of heart rate and blood pressure to near-resting values, facilitates dissipation of heat, reduces potential post-exercise hypotension and promotes removal of lactic acid.⁴

BASIC PRINCIPLES OF EXERCISE

The aim of this section is to provide knowledge of the basic principles of exercise and in particular aerobic and anabolic exercise. Exercise programs may be implemented in a range of settings and may not always have personnel with qualifications and experience in exercise physiology. The following discussion provides a very basic level of knowledge necessary to understand the principles underlying the exercise programs presented in the later sections of this chapter.

EXERCISE PROGRAM VARIABLES

Monitoring exercise intensity

Training heart rate

Heart rate (HR) is used extensively as a guide to monitor exercise intensity due to its relationship between heart function and consumption of oxygen by the working body. The most simple and often-used HR assessment is the percentage of maximal HR (maxHR), which can be estimated as 220 – age. The proposed maxHR intensity range for older people during cardiovascular activities is 60–90% of maxHR.⁴ For example, if an individual is 40 years of age, their maxHR is 180. Their target training heart rate for 60–90% of the maxHR is 108–162 beats per minute.⁴

It is important to monitor heart rate during the exercise sessions to ensure adequate intensity but without working so hard as to induce excessive fatigue. The simplest method is to measure the pulse rate at the wrist, counting the number of beats for, say, 15 seconds and then multiplying by four to calculate beats per minute. However, electronic heart monitors available from any sports store are relatively inexpensive and very convenient.

Rating of perceived exertion

Rating of perceived exertion (RPE) is a valuable instrument in controlling exercise intensity in individuals who have difficulty with HR palpation and especially in cases where medication can alter the HR response to exercise (e.g. beta-blockers).⁴ The best known and established RPE scale is the Borg scale. This scale was developed to allow the participant to subjectively rate their feelings during exercise, taking into account fitness level, fatigue and environmental factors.⁴ More recently, Robertson and colleagues (2003)⁸ developed the OMNI scale, which uses verbal and pictorial descriptors along a numerical scale of 0–10 to rate an individual’s perceived exertion. This scale has been successfully validated with children and young adults from both sexes during cardiovascular⁹ and resistance exercise,⁸ and may also be an option for exercise sessions with older people and patients. RPE can be taken at different points during an exercise session—following each set of an exercise, for example. It can also be taken after the end of the session, which provides a global rating of the exercise session intensity. This measure of session RPE provides essentially the same information as taking multiple measures throughout the session. A sample RPE scale suitable for older people exercising is contained in Figure 9.1.

FIGURE 9.1 RPE scale for older people

The talk test

As a method of making exercise prescription more simple, an informal guideline, widely referred to as the talk test, has arisen within the exercise community. This guideline suggests that if the exercise intensity is such that the patient can just respond to conversation, then it may be just about right (that is, within accepted ranges of exercise training intensity). The ability to converse during exercise (that is, to pass the talk test) has been shown to produce exercise intensities consistently within the parameters suggested in clinical guidelines for exercise training in a variety of populations.¹⁰ The talk test appears to be a practical way for people to monitor their intensity during exercise, and an advantage of this method is that it does not require any equipment and no training is needed to understand your ability to speak based on how hard you are working. Because research has shown this method to be very consistent, people can use it in their everyday lives, in gyms or when working out at home, to meet their health and fitness goals while reducing the risk of injuries or other complications that can happen with over-exertion.

Intensity during resistance training

Intensity when resistance training refers to the relative load or resistance that the muscle is working against—or, looking at it another way, the percentage of the muscle’s maximum strength that is exerted during the training movement. This is often expressed as ‘% 1RM’, the load lifted as a percentage of the maximum that the individual can lift only once. Another common method for describing intensity is in terms of repetition maximum—that is, how many repetitions can be completed before muscular failure occurs and the load cannot be lifted again. Thus, a 6 RM load is a higher intensity than a 10 RM load. For the older population, the intensity must be sufficient to produce the structural and functional changes required or at least stem functional and structural decline. For resistance training, the intensity should be no lighter than 12 RM. For a person who has not performed resistance training in the past 12 weeks, the intensity in the initial few weeks should be kept low, to reduce muscle soreness. For this person an initial intensity of 8–12 RM is appropriate, increasing over the first 4 weeks to 6–10 RM.

FREQUENCY

The number of training sessions completed each week is termed ‘frequency’. For resistance training, one session per week, while better than none, is sub-optimal. The target should be at least two sessions per week and the ideal is three sessions per week.

An optimal training frequency for cardiorespiratory fitness in healthy adults has been proposed as three to five times per week, depending on the intensity of the exercise (see Boxes 9.1 and 9.2). However, de-conditioned individuals are likely to improve their condition with lower training frequencies.⁴

VOLUME

Volume indicates the total amount of work completed while training. For resistance training, it is usually weight × repetitions × sets. For the older population, each session should consist of 3–4 sets of 6–9 different exercises. However, lower training volumes (e.g. 1–2 sets) are more appropriate in the initial stages of training (e.g. the first few training sessions).

With regard to cardiorespiratory training, the combined duration and intensity of an exercise bout result in the expenditure of energy and calories, giving health benefits from the activity. The duration of cardiovascular activities recommended by the ACSM ⁴ for healthy older adults is 20–60 minutes of continuous or intermittent (minimum of 10-minute bouts accumulated during the day) of aerobic activity training.

MINIMUM INTENSITY

When training for strength there appears to be a load below which no training adaptation will result. This may vary depending on training state, muscle group and the individual; however, the lifting of very light loads without maximal effort seems to be ineffective for increasing maximal strength and muscle power. Reiterating the comments above, the intensity should be at least 12 RM and within the first 2–3 weeks progress to a load of 6–10 RM.

In terms of cardiovascular exercise, the minimum intensity for useful benefit is most likely 60% of maxHR.

PROGRESSIVE RESISTANCE TRAINING

In order to stimulate the neuromuscular system towards adaptations conducive to increased muscle strength and power, the training performed must place the system under a greater load than it is accustomed to. As previously defined, this is termed ‘overload’ and in strength development translates into using the muscles of the body to exert forces at or near their maximum potential. The neuromuscular system adapts to the training with increases in muscle size, improved coordination, better motor unit recruitment and at higher firing frequencies, and the result is an increase in strength. However, as strength increases, the initial overload becomes progressively less relative to the increased maximal strength capability, and thus the stimulus to adapt declines if the person continues to train with the same absolute loads. This brings us to the very important concept of progressive resistance training. To continue to elicit gains in muscle strength and power, the loads must be progressively increased so the relative intensity remains high enough to provide an adequate overload. By expressing intensity as % 1RM or specifying a load which can only be lifted a given number of times, the overload is progressive because as strength increases, so do the training loads and thus relative intensity is maintained.

REVERSAL

Just as the body adapts to overload by increasing performance, it also modifies capacity in response to a decrease in physical activity—this is known as ‘de-training’. For example, when a person stops regular resistance training, their strength level gradually returns to what it was prior to the commencement of the program. Importantly, the higher the level of strength attained through training, the longer it takes to return to pre-training levels. Further, one can reduce the amount of resistance training performed each week and still maintain strength at or near the level attained through training. In other words, the volume of training required for maintenance of strength is much less than that required to achieve a given strength level. Similar effects occur with aerobic fitness.

VARIATION IN TRAINING

Two foremost factors when designing training programs are: the principle of overload (already discussed); and variation in training. To provide an overload and thereby continue to stimulate the body to adapt, the training must be novel—it must change in character. The more novel the task, the greater will be the changes in performance capacity towards the new task.

Designing a resistance training program which involves performing, say, three sets of 6 RM with six different exercises is relatively straightforward. As strength increases, the 6 RM load lifted increases and the overload is maintained. However, such a program involves no variation and will not prove as effective as a program with greater variation in exercise selection, intensity and volume. The principle of variation relates to changes in program characteristics to match changing program goals as well as to provide a changing target for the body to adapt to. The careful planning and implementation of this variation is known as periodisation.

The importance of variation in training for maintaining motivation should not be underestimated either. Making the program novel and varying the program parameters is important to avoid boredom, staleness and over-training. It will also increase compliance with the program and help avoid people dropping out of the training program.

All program parameters can be modified to achieve variation in the training. Intensity and volume are obvious choices and it is well accepted that within a week there should be heavy and light days, and the volume should undulate over longer periods of 4–12 weeks or more. However, subtle changes to exercise may include:

• varying the depth of the squat or leg press exercise

• performing explosive exercises

• slowing the tempo down and using ‘super slow’ training

• combining supersets, pre-fatigue, and upper and lower body combinations

• heavy eccentric training, which involves using a heavier resistance during the lowering portion of an exercise

• performing circuit training rather than traditional resistance training

• multi-sport aerobic training, swapping between cycling, running, swimming, paddling and rowing exercise

• swapping sessions between continuous aerobic exercise and interval-type training.

The key is to alter the nature of the overload to encourage the neuromuscular and cardiorespiratory systems to continue to adapt. This becomes more critical as the person becomes more experienced with this mode of exercise.

PLANNING AN EXERCISE SCHEDULE

Maintaining an exercise habit throughout life can be difficult, especially when so many aspects of work and family life compete for our time. For this reason it is helpful to develop an exercise plan for the long-term with realistic goals in mind. This might be as simple as a calendar for the week listing the exercise sessions, start and end times, and the activity. Longer-term planning might entail preparing for a particular event such as a fun run, milestone birthday or the check-up with the family doctor. A 12-week plan is a workable strategy because it is long enough to allow variation in volume, intensity and activity type while also being sufficient to produce significant and observable improvements in health and fitness. This plan can then be repeated or modified according to the season, exercise opportunities and increasing fitness.

The exercise schedule in Table 9.2 provides sufficient exercise to meet the recommended guidelines for someone under 65 years of age. The intensity should be specific to the individual but within the range previously prescribed.

TABLE 9.2 Example of an exercise schedule for a person under 65 years of age

BARRIERS TO EXERCISE

No one said it was easy to start an exercise program and then stick to it. There are many barriers to exercise that must be overcome. The greatest by far is lack of motivation to change one’s behaviour. The GP can be a powerful influence in taking the patient through the stages of change necessary to make exercise a lifelong habit. Convincing the patient of the importance of exercise for their health and even instilling some fear of the consequences of a sedentary lifestyle can be all it takes to start the process. Other personal, financial, environmental and societal barriers can make it difficult to exercise. However, these can all be overcome if the motivation of the patient and the support of their family and friends is sufficient. Regardless of a patient’s illness or injury, there is still the potential to perform some form of physical activity. For example, research in patients with various cancers indicates that exercise can be tolerated, is effective for improving physical and mental health and may even be enjoyable. Lack of financial means is often cited as limiting exercise opportunities but effective exercise programs do not necessarily require expensive equipment and specialist trainers. A quality exercise program meeting the minimum recommended requirements can be achieved in the home with little or no equipment if the patient is given specialist advice to enhance their motivation to exercise. It has been demonstrated that the environment in which the patient lives can affect their opportunities for exercise. For example, a neighbourhood that appears to be unsafe, and has graffiti and broken and dangerous pathways is clearly not conducive to pursuing a walking program. Societal influences can also reduce a patient’s willingness to maintain an active lifestyle. Teenage girls are less likely to exercise, because of peer pressure. Certain religious and cultural groups devalue exercise or actively discourage it. Many children believe that their elderly parents should rest, not exercise, especially when ill. Exercise research indicates that this strategy is counterproductive.

All these barriers to physical activity can be overcome with education and support.

SAFETY AND AVOIDING INJURY

The most effective strategy for reducing injury risk is to seek appropriate expert advice prior to embarking on a new exercise program. For people under 35 years of age and with no cardiovascular risk factors or prior history, exercise can be performed with relative safety. If not, then a medical consultation with a GP is recommended to check family history and current health status, and assess possible risk. If risk is deemed low then the patient might join a health and fitness centre or take up a sport or recreational activity of their choosing. However, if there are issues of concern, a consultation with an exercise physiologist is recommended. The exercise physiologist will perform a more detailed assessment of exercise risk, perform various tests to determine the person’s fitness capacity and then design an appropriate exercise prescription. For individuals with existing chronic disease, consultation with an exercise physiologist is advisable to obtain safe and effective exercise guidelines. Patients with existing musculoskeletal or neuromuscular injuries should be treated initially by a physiotherapist and their exercise program modified.

Exercise can be performed in two broad categories of environment:

• controlled environments—conditions are relatively stable, appropriately qualified personnel are on hand, emergency equipment such as automatic defibrillation, oxygen and first aid are available, and emergency procedures are in place and effective, with immediate contact with ambulance or medical personnel if required; includes most health and fitness centres, exercise clinics and some sporting facilities

• uncontrolled environments—the listed facilities and personnel are not all available; includes exercise at a park or beach, sporting field or any other facility which does not have emergency procedures in place.

Millions of people in Australia exercise each day in ‘uncontrolled’ environments without incident. The issue is ameliorating risk, such that high-risk patients should either exercise only in controlled environments or reduce exercise intensity to lower the possibility of adverse events.

INJURY

The incidence of injury is relatively low, especially in controlled environments with a patient undertaking a program designed and delivered by an exercise physiologist. People often get injured when they begin exercising after being sedentary with no planning or gradual return to exercise volume. For example, lifting weights at home alone can be dangerous. Doing high-intensity exercise without warm-up and cool-down and building gradually in fitness to this level can be dangerous.

A final word on injury and safety: the consequences of being sedentary far outweigh the risks of exercise. It is a matter of a responsible and planned approach with appropriate support from medical and allied healthcare practitioners where required.

OVER-EXERCISING

Above a certain volume and intensity of chronic exercise, the body is not able to recover and repair sufficiently, resulting in ‘over-training’ syndrome. This is relatively rare in non-athlete populations, and even in athletes it is usually due to over-zealous coaches or parents rather than being volitional on the athlete’s part. In people who are not competitive athletes there are instances of excessive exercising to the point of ill health and injury. Exercise can become addictive and obsessive in certain individuals, to their detriment, but this is a very small minority. Signs include increased incidence of injury, very low body fat or sudden weight loss, increased incidence of upper respiratory infections, anaemia, sleep problems, increased resting heart rate, persistent muscle soreness, depression, irritability and decreased appetite.

The ACSM/AHA guidelines presented earlier ⁵ are recommended exercise to maintain health. The volume of exercise can be increased considerably before over-training becomes an issue, but some simple strategies to avoid the syndrome include:

• making one day each week exercise-free or very light recovery (e.g. walking, water exercise)

• avoiding repeating the same type of exercise on consecutive days

• allowing at least 48 hours between resistance training on the same muscle group

• measuring resting heart rate each morning on waking, to detect increases

• keeping exercise sessions to less than 60 minutes.

EXERCISE AND DISEASE

Meeting the recommended guidelines for physical activity has been demonstrated to markedly reduce the risk of most chronic diseases and so has a strong prophylactic benefit. Once chronic disease progression has produced clinical signs and symptoms there are other key roles for exercise in:

• slowing progression

• alleviating symptoms

• preventing or at least delaying the onset of other chronic diseases.

DON’T SUFFER THE SIDE EFFECTS

Treatment side effects are of concern to patient and doctor, and decisions have to be made regarding the relative risks and benefits. In some instances, exercise prescription as adjuvant therapy can alleviate some side effects and improve tolerance of pharmaceutical, radiation and other treatments. For example, testosterone suppression for prostate cancer results in muscle and bone loss and fat gain.¹¹ Fracture risk is increased and recent reports indicate a high incidence of cardiovascular disease and metabolic syndrome.¹² It is now well established that exercise can alleviate all these side effects (Figure 9.2).¹³ Muscular strength is strongly and inversely associated with incidence of metabolic syndrome and the effect is independent of age and body size. Potential benefits of resistance exercise training to increase muscular strength should be considered in primary prevention of metabolic syndrome.¹⁴

FIGURE 9.2 Potential benefits of exercise for metabolic syndrome

(from Jurca et al¹⁵)

CANCER

Much of the research to date on exercise and cancer has focused on cancer prevention, and there is strong benefit particularly for colorectal and breast cancers. Recently, research has begun to examine the effectiveness of exercise programs for patients undertaking therapy. All the evidence collected so far suggests that exercise plays a beneficial role for most patients during cancer treatment. The evidence also shows that there is very little risk of harm when precautions are taken and professional exercise advice is followed closely.¹⁶

Regular and vigorous physical exercise has been scientifically established as providing strong preventative effect against cancer, with the potential to reduce incidence by 40%. The effect is strongest for breast ¹⁷ and colorectal cancer,¹⁸ but evidence is accumulating for the protective influence on prostate cancer, although predominantly for more advanced disease and in older men.¹⁹

Following cancer diagnosis, exercise prescription can have very positive benefits in improving surgical outcomes, reducing symptom experience, managing side effects of radiation and chemotherapy, improving psychological health, maintaining physical function, reducing fat gain and reducing muscle and bone loss (see Table 9.3). There is now irrefutable evidence from large prospective studies that regular exercise post diagnosis actually increases survivorship by 50–60%, with the strongest evidence currently for breast²⁰ and colorectal cancers,²¹ over follow-up periods varying from 5 to 18 years (see Ch 24, Cancer).

TABLE 9.3 Summary of exercise-induced changes in cancer patients reported in 26 research papers reviewed by Galvão and Newton 2005 ⁷

Increased	Decreased
Muscle mass	Nausea
Muscle strength and power	Fatigue
Cardiorespiratory fitness	Symptom experience
Maximum walk distance	Lymphocytes and monocytes
Immune system capacity	Duration of hospitalisation
Physical functional ability	Heart rate
Flexibility	Resting systolic blood pressure
Quality of life	Psychological and emotional stress
Haemoglobin	Depression and anxiety
	Body fat

OSTEOPOROSIS

It has been suggested that the most effective way to avoid osteoporosis is to build as large a ‘bone bank’ as possible during life so as to be able to make ‘withdrawals’ as we age without depleting to an osteoporotic level.²² Physical activity is the most effective lifestyle factor to stimulate bone accretion but the activity needs to be ground-based and with higher loads and impacts. For example, bone mineral density in weightlifters is higher than for active controls and this continues into later life.²³ The effect is persistent, with one study showing that competitive sport early in life is associated with higher bone mineral density in 75-year-old men.²⁴ Swimming, which lacks impacts and the effects of gravity, does not appear to have a protective effect, and swimmers may actually have a lower bone mineral density than people participating in land-based physical activity.²⁵

Physical activity in later life can improve or at least slow bone loss with ageing, and the most effective activity appears to be anabolic exercise. Walking and similar exercises appear to be too low-intensity, with several studies reporting superior results from high-intensity resistance training,²⁶ and it is significantly more effective than calcium and vitamin D supplementation alone.²⁷

SARCOPENIA

Affecting 60% of people over 80 years old, sarcopenia is a major cause of disability and loss of independence for the elderly. Nutrition (under-nutrition and lack of vitamin D) and decreased hormone levels (growth hormone, testosterone) precipitate some of the muscle loss and the ageing process per se; however, it is clear that reduced physical activity, particularly anabolic exercise, is a major factor. The condition is reversible even in the very old, with appropriate anabolic exercise resulting in large increases in lean muscle mass, fibre cross-sectional area and strength.²⁸ It is well known in athlete and healthy populations that there are optimal combinations of anabolic exercise and nutrition. Specifically, glucose and amino acid intake can be manipulated before, during and after the exercise session to produce much stronger anabolic effects. Supplements such as creatine monohydrate are also effective when combined with anabolic exercise, and more research is being done on their application to patient populations.

ALZHEIMER’S DISEASE

It has now come to light that the genetic and lifestyle risk factors for Alzheimer’s disease are very similar to those for cardiovascular disease. This is encouraging in one respect in that exercise is beneficial; however, it is problematic in that the various populations of the world are becoming less active, or at least a high percentage are already sedentary, and obesity is increasing markedly. As a result of these lifestyle choices and an ageing demographic, the incidence of Alzheimer’s disease is predicted to increase greatly in the future. Exercise has several roles to play here. First, lifelong physical activity can delay the onset of Alzheimer’s even in those with high genetic predisposition. For example, in one population based-study (n= 1740) with 6.2 years follow-up, the reported incidence rate of dementia was 13.0 per 1000 person-years (exercise three or more times per week) compared to 19.7 per 1000 person-years (exercise fewer than three times per week).²⁹ In the early stages, regular exercise slows the progression of the disease, helping to maintain both physical and cognitive capacity. Interestingly, even a single bout of exercise results in an acute improvement in memory and cognitive function in patients with existing disease.

OBESITY

The evidence is clear that the only effective way to lose body fat when overweight or obese is a combination of habitual physical activity and reduction in energy intake. It appears that increased physical activity alone is not as effective as reduced caloric intake, but it is far easier to stick to a lifestyle in which a negative energy balance is achieved 50% through increased exercise and 50% through diet modification. But the application of exercise for weight management has other important benefits. Any fat-loss diet is also a muscle and bone loss diet as these tissues are also affected. Exercise, and in particular anabolic exercise, is critical for preventing these catabolic effects. Second, exercise increases muscle mass, which concomitantly increases resting metabolic rate, enhancing fat reduction. Finally, in terms of patient health, ‘fitness rather than fatness’ should be the focus, as research indicates that a person can be overweight but if they are physically fit then their risk of death is no greater than a person of normal weight.³⁰ The same cannot be said of someone who is of normal weight but sedentary.

ANXIETY AND DEPRESSION

A number of trials have reported reduced risk of anxiety and depression in children who exercise, compared with inactive controls.³¹ The evidence in adults is less convincing due to a lack of clinical trials, but there are indications of a positive effect.³² However, in older people diagnosed with clinical depression, certain types of exercise have been demonstrated to be more effective than routine GP care.³³ This was a single blind control trial which indicated that high-intensity resistance training could produce a 50% reduction in depression rating in 61% of the group. This compared to a similar drop in only 21% of patients in the GP-care group. A 29% reduction was observed in a low-intensity resistance training group, indicating that social interaction was not the only stimulus but the lifting of heavier weights produces some physiological effect benefiting the depressed elderly.

The effects of exercise build gradually but are sustainable throughout life. Initiating exercise in the acute stage will permit a transition to long-term control of depression, hopefully with reduced requirements for medication.