Exercise Prescription for Treatment of Obesity by Chad D. Bailey a Paper

Exercise Prescription for Treatment of Obesity

Chad D. Bailey

A paper submitted in partial fulfillment ofthe requirements for the degree of

MASTER OF NURSING

Washington State University Intercollegiate College ofNursing

December 2001 2

To the Faculty of Washington State University:

The members ofthe committee appointed to examine the manuscript of CHAD D. BAILEY find it satisfactory and recommend that it be accepted.

Lorna Schumann PHD, FAANP, ARNP, Chair

Ed Gruber, PHD, ARNP cJtl~A~ g(bn~£

Jackie Banasik PHD, ARNP 3

Exercise Prescription for Treatment of Obesity

Abstract

Chair: Lorna Schumann

The disease of obesity is a disorder characterized by excessive accumulation of

2 body fat defined as a body mass index (BMI, WT in KG/ Height in M ) greater than 30.

Secondary pathologies associated with obesity include sleep apnea, diabetes and heart disease. Researchers estimate the incidence of obesity to be 17% ofthe population in the

United States and rising. The etiology ofobesity stems from the continued daily accumulation of excess calories over a period of time. The primary treatments for this condition are exercise and calorie restriction. Exercise is underutilized and not well understood by health care providers. Proper exercise prescription implementation is essential in the effective treatment of obesity. 4

TABLE OF CONTENTS

Signature Page 2

Abstract 3

Table of Contents 4

List of Tables 5

List ofFigures 6

Introduction 7

Scope ofthe Problem 8

Definition and Pathopysiology of Obesity 9

Epidemiology 11

Clinical Findings 12

Obesity Screening Criteria and Diagnostic Tools 13

Pertinent History Data 14

Diagnostic Testing 16

Diagnostic Algorithm 16

Treatment 19

Exercise Prescription 20

Summary 26

References 36 5

LIST OF TABLES

Table 1 Suggested Differential Diagnostic Labs 28

Table 2 History Key Questions for Differential Diagnosis 29

Table 3 Clinical Findings 30 6

LIST OF FIGURES

Figure 1 Diagnostic Algorithm 31

Figure 2 BMI 19-24.9 33

Figure 3 BMI 25-29.9 34

Figure 4 BMI 30 35 7

Introduction

Unlike a variety of illnesses treated in our health care community, obesity is difficult to address or treat effectively. This article addresses issues related to identifying those at risk for developing obesity and appropriate exercise treatment guidelines using the theoretical framework of stages ofchange to facilitate treatment.

Stages of Change framework aids providers in understanding how and why people change lifestyle behaviors in helping to promote active changes in behavior towards a healthier lifestyle. Prochaska & Dichlemente developed the framework in

1981, and it is formally identified as a trans-theoretical model dealing with Stages of

Change (Prochaska, Norcross & DiClemente, 1994). Its relevance stems from the need to understand how the individuals' readiness to implement life style changes will impact how the provider approaches treatment ofthe individual's obesity. Eventual treatment and potential correction of obesity is primarily through life style modifications and maintenance ofthose modifications. The stages of change model consists of five stages

1. Pre-contemplation - Individuals not intending to change their current

behavior.

2. Contemplation - Individuals considering changing their current behavior.

3. Preparation - Individuals making small changes in current behavior in

preparation for a larger life style modification.

4. Action - Individuals actively engaging in new behaviors.

5. Maintenance - Individuals sustaining the changes in their current behavior

over a period of time. 8

These stages progress in a cyclical pattern, starting at a point and progressing

through the levels in a predictable manner. Progression through the stages is based on an

individual's preparedness for change ofcurrent health behaviors. The practitioner must

recognize that different individuals will present at varying stages of change. The patient

will progress predictably through all stages. At any point relapse may occur to a previous

stage, thus requiring the patient to progress through the stages again.

Scope ofthe Problem

Obesity is the most common nutritional disorder in the developed world and is

associated with significant metabolic diseases (Campfield, 1999). The percentage of

overweight individuals (BMI greater than 25) in the United States (US) is estimated to be

59.4% of men and 50.7% of women, a total of97.1 million people (Kuczmarski, Carroll,

Flegal & Troiano, 1997, Must et aI., 1999). Mokdad et aI., (1999) found that obesity has

increased in prevalence from 12.0% to 17.9%, an overall increase of 5.9% from 1991

1998.

The high prevalence ofobesity results in an associated cost, estimated to be 190 billion dollars every year (Bray, 2000). This cost of obesity is not only a direct result of its pathology, but also a result of secondary pathologies that develop with increased weight. Complications of obesity that can be attributable to the metabolic changes associated with obesity include diabetes mellitus, gallbladder disease, hypertension, cardiovascular disease and some forms ofcancer (Bray, 2000). Obesity makes people at risk for a number ofdiseases that are among the leading causes of death in the US. In

1999, 32,500 deaths were attributed to obesity in those individuals or patients with a body

2 mass index (BMI) ofgreater than or equal to 30 kg/m . Decreased quality oflife 9

associated with osteoarthritis, sleep apnea, and the mental difficulties (i.e. depression and poor self esteem) associated with increased BMI complicate the underlying issue of

obesity (Bray, 2000). These secondary pathologies are highly debilitating and largely preventable or modifiable with proper weight reduction and control.

Exercise prescription can help correct underlying behaviors that lead to the development of obesity. The rate ofphysician counseling about exercise is low (29-35%) nationally and may represent important missed opportunities for primary prevention

(Nawaz, Adams & Katz, 1999; Wee, McCarthy, Davis & Philips, 1999). Only 5-25% of the American population exercises regularly or vigorously enough to produce cardiovascular fitness and known epidemiological benefits (Tiffany, 2001).

Changing the current status ofthe obesity epidemic is further complicated by the large percentage ofthe population in the pre-contemplation stage. Obese patients are less open to the facts and gravity of the situation and its implications on their health. At any given time approximately 20% ofthe population is in the preparation or action stage

(Prochaska, Norcross & Diclemente, 1994).

Definition & Pathophysiology of Obesity

Overweight is defined as a BMI above 25 kg/m2 and opesity is defined as a BMI of 30 kg/m2 of body fat (World Health Organization, 1997). Obesity is an insidious process presenting painlessly over a period of months to years. A variety of contributing pathologies (see table1) include neuro-endocrine, Cushing's syndrome, hypothyroidism, polycystic ovary syndrome, growth hormone deficiency, pregnancy, drug induced, smoking cessation, sedentary lifestyle, nighttime eating syndrome, binge eating disorders, and progressive hyperphagic obesity (Bray, 2000). Though these pathologies may result 10 in the development of obesity, the incidence ofthese diseases as the primary cause fails to explain the incidence of obesity seen in our society.

The primary pathology behind the development ofexcess weight is related to a state of energy excess. Obesity results from an imbalance between the energy value of the food individual's eat and daily energy expenditure (Bray, 2000; Campfield, 1999;

Chisholm et aI., 1998; Weinsier, Hunter, Heini, Goran & Sell, 1998). In its simplest form, the development ofthis condition results from accumulation of nlore energy than is expended in a day. This excess energy then accllmulates in the form of adipose tissue.

The development and maintenance of obesity can be considered to result from the integration, or the accumulation, of small daily errors in energy balance over several months and years (Campfield, 1999). Individuals that consume more energy than they expend, put themselves at increased risk for the development ofobesity. Individuals developing obesity from this common cause tend to be in the pre-contemplation stage.

Genetics play what is believed to be a small, but unquantified role in the developnlent ofobesity. The most commonly accepted model for the role of genetics in human obesity is an interaction between genetic predisposition and environmental factors

(Bray, 2000; Campfield, 1999; Chisholm et aI., 1998, Weinsier et aI., 1998). Though there has not been a gene identified that explains the large percentage ofthe population that is obese, genetics can make people prone to the development of obesity. A fanlily history of obesity correlates with the development of obesity through out an individual's lifetime. Despite some slight increase in the susceptibility to the development ofobesity, the primary factor in developing obesity is environmental. Genes permit individuals to 11

become obese; the environment determines if people become obese (Weinsier et aI.,

1998).

Epidemiology

Throughout the last part of the late 1800's and through the early 1970's there was

a fairly stable level of obesity generally representing about 12% ofthe United States

population (Mokdad et aI., 1999). Obesity has traditionally been more prevalent among

the less educated, lower socioeconomic class, and the elderly. Prevalence among the

upper economic classes, educated and young has risen (Campfield, 1999). The

prevalence of obese individuals increased from 12% (traditional until the last half of the

twentieth century) to an incidence of nearly 20%, occurring from birth to 70 years of age

(Seidell & Flegal, 1997).

Reasons for this significant increase are multi-factorial. Modem societies have

developed a variety ofmachines that have resulted in energy conservation, ie. tractors, trailers and cars. New developments in society have created a culture more sedentary than any other culture in the history ofthe United States. As society continues to

develop, a further tendency towards energy conservation versus expenditure, the scope of the problem will continue to become more widespread and important.

Along with the changing technology of modem society and its impact on the

current epidemic of obesity, cumulative cllanges have occurred in diets. These changes have resulted in a current diet high in saturated fat and high calories. "Many of us live in

a world with a large and increasing variety of highly palatable food, together with

declining incentives and opportunities for physical activity" (Campfield, 1999 pg. 14).

These factors have created a world in which the amount of physical activity and energy 12 expenditure have decreased to an all time low, in which the number of calories being consumed have increased to an all time high (Campfield, 1999). The epidemiology of obesity is dependent upon the technology, recreation and dietary aspects of a particular society.

Clinical Findings

An individual may not be aware ofthe onset of obesity. Excess adipose tissue generally accumulates over an extended period oftinle. The change to the individual may seem more the norm than the unusual. Overweight or obese people often remain asymptomatic in the early to mid stages ofobesity, with the only complaint of a cosmetic nature.

Another difficult aspect ofthe presentation of being overweight or obese is the person's perception that obesity simply is a normal part of aging or ofparticular life situations, such as pregnancy. Strategies for the early identification ofthe clinical presentation of obesity include routine monitoring of weight, calculation of BMI and measurement of waist circumference at the time ofan office visit. (See Table 3) Routine monitoring offsets the insidiousness of obesity. Routine screening will lead to a well informed provider and patient. This screening may additionally help motivate the patient by facilitating self-awareness ofbodily changes and recognition ofthe current state of change. Such awareness can promote and facilitate progression in the stages of change.

This initial step of making an individual aware oftheir obesity will allow the provider to promote self-change (or the progression from one stage of change to another) and begin the process of empowering them to make a change. If a patient is unaware of a need for change, they will never attempt to initiate change to correct the underlying lifestyle 13

behavior causing the problem. Obesity often becomes an issue for the provider or the

patient in the later stages when both are forced to deal with the effects ofuncorrected

obesity. The most prevalent complaints come as a result of secondary pathologies such

as osteoarthritis, diabetes, and CAD. Obesity is easy to recognize, but difficult to treat.

Obesity Screening Criteria & Diagnostic Tools

The most clinically appropriate diagnostic plan offers both prevention and

treatment. "The treatment ofthe overweight or obese patient consists of a two step

process: assessment and treatment/management. Assessment requires determination of

the degree of overweight and overall risk status. Management includes both reducing

excess body weight and instituting other measures to control accompanying risk factors"

(Expert Panel, 1998 pg 1).

The only way to reveal weight changes and progression towards obesity is

regular assessment ofweight, height, and waist circumference. Body Mass Index

(derived from the weight and height assessment) indicates individuals with a relatively high body fat percentage that puts them at risk for obesity and related diseases. The BMI has a sensitivity of95% and specificity of 100% for obesity. BMI is a general population measure and may not be applicable to small sub-groups ofthe population such as the avid weight lifter (who should be easily identified by exam and history). BMI does not measure the difference between lean body mass and fat mass and may inaccurately

indicate someone as being obese who is not in this subgroup, due to the high level of lean body mass in relation to their height and predicted weight. Lean body mass is then misinterpreted as fat mass by the BMI calculation and then becomes an inaccurate 14 measurement of body fat percentage (Kushner & Weinsier, 2000). For the general population, the BMI is an accurate measurement of body fat percentage.

Monitoring waist circumference (WC) helps el1sure that possible outliers are encompassed in this diagnostic approach. Lean, Han, & Seidell 1998, found that people with excess abdominal fat accumulation have a three fold increase in the incidence oflow back pain, decreased physical functioning, type 2 diabetes and cardiovascular disease.

Men with a waist circumference greater than 102 cnl (42.5 in) are at greatest risk.

Women have a 2.7 increase in the same associated disease factors with a waist circumference greater than 88 cm (36.5 in). Waist circumference has sensitivity and specificity both greater than 95% for those at risk for obesity related risk factors (Han et aI., 1996; Lean, Han & Morrison, 1995). Abdominal fat accumulation is a predisposing factor for disease pathologies associated with being overweight or obese. By combining

BMI with WC, the number of at risk people not being accurately screened should represent a relatively small and easily identifiable percentage ofthe population.

Making the patient aware ofthe presence or possible inlpending development of obesity and its adverse affects on their health helps the patient become more aware ofthe state oftheir body. Such self-awareness possibly helps patient's progress from their current stage ofchange to the next level.

Everyone who comes to the office for a visit should routinely receive height, weight and waist circumference measurement every visit. Routine collection ofthis data provides a simple efficient process to calculate BMI in conjunction with use ofwaist circumference, to identify those at risk.

Pertinent History Data 15

Once at-risk individuals have been identified, the practitioner should obtain some basic history and laboratory data. The history is important to ascertaining a person's current condition and capability to participate in treatment regime (See figure 1 & table 2 regarding the history questions). Obtaining a list of the current medications and their possible effects in the development ofweight gain helps practitioners further refine the treatment program.

Information about the life style a person leads provides important data to control the development and maintenance of obesity. An individual's experience with obesity helps determine the likelihood ofcomplying with therapy and previous treatments for their condition. Eating habits are a major factor in the development and treatment of obesity. Determining physical conditions that limit activity can help the provider evaluate their contribution to the development ofobesity and to make appropriate alterations in the treatment regime. Response to previous weight loss attempts aid in identifying what variables a person will respond to in treatment. Physical activity levels should be assessed to determine how difficult it might be to motivate an individual to exercise.

Motivation and readiness to deal with obesity will impact a person's willingness to complete a treatment program. Understanding an individual's information will also be important in helping an individual progress through the stages of change. A provider must be able to understand what behaviors are keeping the patient in the current stage of change, and by doing so may educate the patient and empower them to make changes and progress through the stages of change. Family history information is inlportant to ascertain the presence of cardiac risk factors and diabetes. Lastly, review of systems is 16 important in the identification ofpossible associated pathologies and to differentiate the origin of a person's obesity, ie., hypothyroidism vs. life style.

Diagnostic Testing

A fasting lipid profile should be obtained to determine cardiac risk factors. A fasting glucose test should be obtained to assess for the presence of diabetes, a cardiac risk factor often associated with obesity. An ECG should be done to assess proper functioning ofthe cardiovascular system for evaluation of existing pathology that might hamper treatment. The American College of Sports Medicine recommends that men over

40 years of age, women over the age of 50, people with two or nlore cardiovascular risk factors, or people with known cardiac disease should complete an exercise stress test, before the initiation of vigorous exercise (Kligman, Wewitt, & Crowell, 1999).

Diagnostic Algorithm

The diagnostic algorithm starts with routine monitoring integrated into every office visit (See Figure 1-4). The process should begin with the attainment of a person's weight, height and waist circumference. Once those measures are obtained the next step is to calculate BMI using the following formula: weight in kilograms divided by height in meters squared or by a standard BMI chart. Following the calculation ofBMI, the next step is to determine obesity-associated pathologies and potential complicating risk factors. Associated pathologies include CAD, diabetes mellitus, osteoarthritis, sleep apnea, HTN, smoking, hyperlipidenlia, personal history of obesity, stroke, gallstones, gout, malignancies (uterine, colon, breast, prostate), and men age 40 or women 50 and older (Kern, 1997). Additional laboratory data should be obtained by the index of suspicion related to history and physical exam (Kushner & Weinsier, 2000). Once the 17 appropriate information has been gathered the provider can assess the need for intervention.

Individuals with a BMI 19-24.9 (normal weight as indicated by WHO, 1997), waist circumference less than 102 cm for men! less than 88 cm for women with or without any cardiovascular risk factors do not need intervention (Berke, & Morden, 2000;

Despres, Lemieux & Prud'Homme, 2001; Expert Panel, 1998; Han, van Leer, Seidell, &

Lean 1995, Han, van Leer, Siedell, & Lean, 1996; Hazra, 1999; Liemeux, Prud'Homme,

Bouchard, Tremblay, & Despres 1996; Kern, 1997). However, patients should be monitored on a regular basis equivalent to the scheduled physical intervals.

Individuals with a BMI 19-24.9, waist circumference greater than 102 cm for men or 88 cm for women, with or without two risk factors require treatment (Berke, &

Morden, 2000; Despres, Lemieux & Prud'Homme, 2001; Expert Panel, 1998; Han, van

Leer, Seidell, & Lean 1995, Han, van Leer, Siedell, & Lean, 1996; Hazra, 1999;

Liemeux, Prud'Homme, Bouchard, Tremblay, & Despres, 1996; Kern, 1997). Follow-up visits should be scheduled at six-month intervals to monitor progress. Treatment should begin with education on the importance oftreatment, the benefits oftreatment, and the process to expect. The provider and the patient should develop mutual goals in the attainment ofproper weight, such as a waist circumference below the risk indicator. The patient should then begin diet and exercise therapy. An exercise stress test should be obtained before the initiation of exercise therapy in men older than 40, women over the age of 50, those with known cardiac disease and individuals with two or more risk factors to ensure adequate cardiac functioning (ACSM, 1998). 18

Patients who have a BMI 25-29.9 (WHO, 1997) pursue a different course of treatment. Those with a BMI of25-29.9 and a waist circumference greater or less than

102 cm for men and 88 cm for women, with or without two risk factors need a physical exam to assess their conditioning for the initiation ofexercise and diet therapy (Expert

Panel, 1998; Kern, 1997). An exercise stress test should be obtained for those over age

40 for men, over age 50 for women and those with known disease or two or more cardiac risk factors (ACSM, 1998). Those who have a WC greater than 102cm for men/99cm for women should be rechecked in six months to a year for individuals without any cardiac risk factors. Those with two or more risk factors should be seen again in three to six months. While those with a WC below the indicated treatment level and no cardiac risk factors may be rechecked in one year and those with two or more risk factors should be rechecked in six months.

BMI greater than 30 (WHO, 1997), regardless of risk factors should receive a physical exam and exercise stress test. The practitioner should pay attention to physical capabilities, ie., gait, respiratory status and cardiovascular status. Obese patients with a

BMI greater than 30 need to start diet and exercise therapy with follow up on a regular basis, starting at every two weeks, then every four to six weeks (Expert Panel, 1998;

Kern, 1997). Severely physically compromised patients should be seen every three weeks.

After assessing the need to intervene, the practitioner must properly educate the individual to help them progress through the stages of change. An individual advised for the first time ofthe need for intervention, may need a period oftime and reinforcement of the need for intervention before entering a stage of Preparation or Action. The eventual 19

goal of self-change is to help the individual achieve a maintenance stage, where the

largest and most significant progression ofchange in their obesity will be made.

Helping an individual through the stages of change is a process of education,

empowerment, and follow up. First an individual must understand the negative impact of

this condition and what are the possible life long implications to them. Once a person has

a basic and firm understanding ofthe scope of the problem they must be empowered to

make a change and assisted in their self-change. This will involve encouragement and

reassurance that a change can be made that will improve their obesity. They must

understand that they are the only ones that are capable of making this change. Lastly, it

will be important to follow up repeatedly to empower the patient and help them progress through the stages of change and promote weight reduction.

The goal attainment and maintenance step follows the initiation ofmedical management ofthose who are overweight or obese. Progress should be monitored to assess for goal attainment. Once goal attainment is reached, a maintenance program should be initiated to ensure long-term stability at the proper weight (Agrawal, Worzniak

& Diamond, 2000).

Treatment

The treatment plan should include approaches with the same basic premise, the reduction of an individual's fat accumulation. Any appropriate weight loss program

should include diet modification, lifestyle modification, and exercise. Additions to the base plan may include medications or surgery, but these additions offer limited application to the larger populace and therefore will not be addressed. Obesity is a long term disease requiring continuous therapy over months to years (Agrawal et aI., 2000). 20

Exercise Prescription

Exercise is an integral part of an individual's weight loss program and perhaps the part ofthe treatment that is the least implemented and understood. Appropriate exercise is of vital importance in rectifying an individual's obesity. The National Health

Interview Survey, as well as other current studies, confirms the rate ofphysician counseling about exercise at 29-35%. These low rates may represent important missed opportunities for primary prevention (Nawaz et aI., 1999; Wee et aI., 1999). Exercise prescriptions help individuals advance through the stages of change ifthe prescription is appropriate to the current assessed stage of change.

The fundamental objective of an exercise prescription is to create a change in personal healtll behaviors to include regular physical activity (Petrie, Mathews &

Howard, 1996). As with any prescription, the treatment is prescribed at a specific dose intended to produce an intended response (Speed & Shapiro, 2000).

Exercise will positively impact weight loss, muscle tone and secondary pathologies associated with being overweight or obese American College of Sports

Medicine (ACSM, 1998). Aerobic exercise improves cardio-respiratory fitness by roughly 8% (Donnelly, Jacobsen, Heelan, Seip & Smith, 2000; Utter, Nieman,

Shannonhouse, Butterworth & Nieman, 1998). Aerobic exercise has also been shown to decrease body fat, increase fat free mass (muscle), decrease abdominal fat mass, prevent the abnormal accumulation offat, and allow individuals to maintain an appropriate weight (Donnelly et aI., 2000; Kyle et aI., 2001; Ross et aI., 2000). Exercise improves lipid profiles by reducing LDL and increasing HDL levels (Donnelly et aI., 2000; Kodis et aI., 2001). Exercise plays a large role in treatment and control ofblood pressure. 21

Those who do not participate in exercise having a 2.6 times greater chance of having elevated blood pressure (Liu et. aI., 2001). Exercise has a significant impact on improving depression, reducing stress and overall mood (Dimeo, Bauer, Varahram,

Proset & Halter, 2001; Salmon, 2001). Exercise improves insulin's effect and has a beneficial impact on diabetes (Donnelly et aI., 2000; Ryan, 2000). Evidence also suggests that exercise decreases the incidence of gastrointestinal cancer by roughly 50% and may have beneficial effects on other gastrointestinal disorders (Peters, De Vries,

Vanberge-Heregouwen, & Akkermans, 2001). Exercise maintains immune function over a period of time, while lack of exercise results in a declined immune response (Paw et aI.,

2000). Finally exercise improves functional capacity in daily life (Chin et aI., 2001;

McMurdo & Rennie, 1993).

A few basic principles guide exercise and help the patient to obtain its maximum benefits. Integrating sound principles will allow a provider to better utilize an exercise prescription and a patient to understand how to appropriately utilize an exercise program in the action and maintenance stages of self-efficacy (Petrie, Mathews & Howard, 1997).

The overload principle involves the idea that the body will physically

adapt to stress. Overload of a particular body system past its threshold will force

the body to adapt to new physiologic stress. Overload stress causes the body's

tissues during the recovery period between exercise sessions to repair and restore

the tissue to an over compensated state. This principle explains the physiological

progression a person observes from increased stressors in their exercise program.

The specificity principle refers to the body's tendency and ability to adapt

according to the specific nature ofthe training activity. Therefore, the adaptations 22

occur to the metabolic and physiologic systems ofthe specific muscles and tissues

exercised.

The individual differences principle refers to the differences in individuals

differing genotype. Variations in the adaptations can be expected from a given

exercise depending on an individual's particular genetic makeup.

The reversibility principle indicates that the benefits ofexercise are lost

when overload stops. The rate ofdecline may vary, but decline is inevitable when

the physiologic stressors required to get an individual to a particular level of

fitness are removed that individual will lose the benefits that had been obtained.

The progression principle is a further adaptation ofthe overload principle.

Since the body adapts to stressors that are applied over a period oftime, to

continue to make improvements in fitness, the stressors need to increase over a

period oftime (Petrie, Mathews & Howard, 1997).

Exercise prescription is designed to guide individuals to improve their level of physical fitness in a safe manner, as they exercise to achieve the desired effect. The goal behind an exercise prescription is to achieve physical fitness, described by the ACSM as the ability to perform moderate to vigorous levels ofphysical activity without undue fatigue and the capability ofmaintaining such ability throughout life (ACSM, 1990;

Lewis & Lynch, 1993). An exercise prescription improves a number ofmeasurable categories: that allow an individual to achieve the ACSM definition ofphysical fitness.

The measurable categories include cardio-respiratory endurance, nluscular strength, flexibility, muscular endurance, and body composition. 23

The provider should specify the mode, frequency, duration, and intensity of an exercise prescription to ensure proper understanding and maximal benefit (Petrie,

Mathews, & Howard, 1996). The guidelines present a framework with which the health care provider may individualize treatment to meet a patient's needs (McConnell, 1996).

An exercise prescription is dependent on the specific disease state, as well as age, medication and psychosocial factors (Speed & Shapiro, 2000). A dose response to exercise derives benefits through varying quantities ofphysical activity ranging from approximately 700 - 2000 plus kilocalories of effort per week (Fletcher, Balady & Blair,

1996; Lee, Chung-Cheng & Paffenbarger, 1995; Surgeon General, 1996). Each session of exercise should include a warm IIp period, exercise period and cool down period. The aerobic training portion ofthe program is generally the largest component due to the fact that it has the largest ability to improve disease states, modify risk factors, and body composition (Lampman, 1997).

For cardio-respiratory fitness in healthy adults, aerobic training 3-5 days per week for 20 - 60 minutes a day is recomnlended. The exercise program can be carried out in ten-minute bouts, accumulated throughout the day (Pollock et aI, 1997). The desired intensity ofthe exercise should range from 55 - 65 % ofthe heart rate max (HRmax).

Wenger & Bell (1986) found that training fewer than 2 days per week generally does not result in a meaningful increase in V02 max (a measure of oxygen consumption used to evaluate an individual's cardio-respiratory status). Training for more than five days per week shows only minimal improvement in V02 max over the recommended 3-5 days, while increasing the incidence of injury disproportionately (Blair, Hohl, & Goodyear,

1987; Hickson, Foster, Pollock, Galassi & Rich, 1985; Hickson, Kanakis, Davis, Moore, 24

& Rich 1982; Hickson & Rosenkoetter, 1981). There are significant benefits in exercise accumulated over a day to achieve the reconlmended time specified (ACSM, 1998).

Duration oftraining is based upon reasonable daily accomplishnlents by the average

American, with a minimal duration for benefit and a variable range based upon the time available each day (ACSM, 1998).

Intensity of exercise should be adjusted to the individual's desired effect (related to the dose effect of exercise). For those who desire to improve health, but not necessarily achieve a high level of physical fitness, the lower end ofthe intensity may be used. A HRmax of 55% (HRmax is equal to 220 minus the age ofthe individual) resulted in measurable and significant impact in fitnesslhealth (Crews & Roberts, 1976;

Kavanagh & Shephard, 1990; Sharkey, 1970). Individuals seeking benefits of greater impact on their health and physical functioning can exercise at 65% of HRmax. HRmax above 65% was not shown to have any further significant improvement in V02 max past that intensity (Wenger & Bell, 1986). HRmax is appropriate in healthy individuals without cardiac disease or cardiac modifying drugs. The use of exercise prescription by heart rate is not an appropriate modality for patients on cardiac medications that alter the heart rate response to exercise eg., digoxin and beta blockers (Lampman, 1997).

Referring these individuals for graded exercise testing to determine an appropriate heart rate training zone offers the most time efficient and effective process.

Aerobic exercise should involve a sustained dosage of rhythmic actions of large muscle groups varied by intensity duration and frequency (Speed & Shapiro, 2000).

Varying aerobic activity ensures a well-balanced development of muscles and ensures maintenance of a participant's interest in sustaining the behavior. 25

While aerobic exercise is the largest component of a well-balanced exercise program muscular resistance training is also important. Muscular resistance training in exercise prescription is largely aimed at the improvement in an individual's physical function, muscular strength and endurance (Fiatarone et aI., 1990; Gettman, Ward &

Hagman, 1982). Tolerance to weight bearing activities may be significantly improved by first improving muscle strength, joint stability and balance. Thus increased tolerance will improve an individual's ability to implement aerobic activity requiring at least a functional level (Mazzeo & Cavanagh, 1998). Muscular resistance training can build muscular strength or endurance depending on the number of sets prescribed and the number repetitions within those sets. Muscular strength is best developed by using heavier weights with few repetitions, and muscular endurance is best developed by using lighter weights with a greater number ofrepetitions (Borer, 1995). For a well-balanced program an individual should perform 8 - 10 upper and lower body exercises 2-3 days a week with sets of 1 containing 8-12 repetitions (Pollock, 1998). Performing more than one set does not result in significant improvement over the benefits achieved from performing one set (Feigenbaum & Pollock, 1997). Sessions should be kept under sixty minutes per session, because sessions ofgreater time frame are associated with higher drop out rates (Pollock, 1988). The patient may find working with a trainer in a local gym helpful.

Stretching will help to prevent injuries, improve joint function/range of motion and enhance muscular performance (Raab, Agre, McAdam & Smith, 1988; Worrell,

Smith & Winegardner, 1994). The ACSM (1998) recommends that static stretches be held for 10-30 seconds, with at-least four repetitions per muscle group, 2-3 days per 26 week. Holding stretches for the recomnlended duration at the point of mild discomfort enhances flexibility, without significantly greater benefit from longer durations (Bandy &

Irion, 1994; Taylor, Dalton, Seaber & Garrett, 1990). More than four repetitions of stretching showed minimal gains in subsequent range ofmotion (Taylor et aI., 1990).

An exercise prescription program should be modified according to a person's ability, previous experience, educational level and stage of cllange. For example, an individual unable to walk due to severe osteoarthritis ofthe knee, will be unable to run, walk or probably ride a bike, but the individual may be able to swim or row.

Summary

Weight loss and the nlaintenance of weight loss demand a long-term commitment

(Agrawal et aI., 2000). Exercise provides the primary means of achieving the necessary weight loss. A person can change and maintain their weight at an appropriate level by achieving a level of maintenance, or a state in which they can keep themselves at a healthy weight. Self-change is important in understanding how an individual will progress through the process of life style modifications necessary to achieve risk factor reduction, weight loss and a healthy life style. Once a treatnlel1t program is initiated and maintained, people can overcome this medical condition (Agrawal et aI., 2000).

It is important to remember that stages of change will guide the treatment program the provider implement. The exercise prescription the provider implement can only be as aggressive as the stage of change that the patient is in. As the patient progress through the stages of change the complexity ofYOllr treatment program and the ambitiousness ofthe goals progress. Lastly, it is essential to remember that success in the fight against obesity is a function of the individual's willingness to intervene and 27 participate in treatment (self-change) and it is the provider's obligation to help empower them to do so. 28

Table 1 Suggested Differential Diagnosis Labs Disease State Diagnostic Test

Pregnancy Urine or Serum HCG

Cushing's Dexamethasone Suppression Test Disease

Hypothyroidism TSH,T4 Growth SerumGH Hormone Deficiency

Polycystic Androgens Ovary Fasting Glucose Test Syndrome LH

Source: Crombleholme (2000), W. R., Fitzgerald, P. A. (2000), MacKay, H. T. (2000) 29

Table 2 History Key Questions for Differential Diagnosis

Smoking Recent history of smoking Cessation cessation. Often associated with recent increases in snacking.

Sedentary Life Evident in the history with respect Style to activities that reveal energy expenditure.

Diet Diet high in caloric intake and low in energy expenditure. A 72-hour diet history may be helpful.

Night Tinle Revealed by a history of large Eating amounts of caloric consumption in Syndrome the nocturnal hours.

Binge Eating Revealed with times of large Disorders energy consunlption for discrete periods oftime. Then it is often associated with purging of ingested calories.

Progressive Associated with larger and larger Hyperphagic consumption of calories over a Eating period oftinle, leading to an extreme excess of energy consumption. Drug Induced Associated with the use of drugs that cause weight gain. Drugs such as steroids and contraceptives are prime candidates. Polycystic Often associated with infertility, Ovary obesity, type 2 diabetes and Syndrome hirsutism. Should be identified in the history.

Source: Bray, 2000 30

Table 3 Clinical Findings

Body Mass Index Waist Circumference -a general population measure -indicates those at risk for obesity related risk factors -95% specific regardless Oof BMI

, -100 specific -955 sensitive

-95 specific

Source: Han et aI., 1996; Lean, Han & Morrison, 1995 31

Figure 1. Objective & Subjective Data for Diagnosing & Treating Obesity

Wt Measurement I Ht Measurement

Calculate BMI Sensitivity 98% Specificity 100%

Measure Waist Circunlference Sensitivity> 95% Specificity> 95%

History Key Questions

Medications Social History Family History Previous Experience With Obesity History of Weight Loss Eating Habits Physical Conditions Limiting Activity Response To Previous Weight Loss Attempts Physical Activity Patterns Motivation & Readiness Review of Systems

DETERMINE DISEASE RELATED RISK FACTORS 32

CAD DIABETES MELITUS SLEEP APNEA HTN SMOKING HYPERLIPIDEMIA AGE> 45 MEN> 65 WOMEN OSTEOARTHRITIS HISTORY OF OBESITY

Laboratory Data

Fasting Lipid Profile Fasting Blood Glucose EKG Additional laboratory data determined by index of suspicion. Exercise stress test should be obtained in those older than 40 for men, 50 for women, w/2 or more risk factors, or known cardiac disease

Sources: Bray, 2000; Campfield, 1999; Expert Panel on the Identification, Evaluation, and Treatment of Overweight in Adults, 1998; Han, 1998; Han, van Lier, Seidell & Lean 1996; Hazra, 1999; Kern, 1997; Kuczmarski, Carroll, Flegal & Troiano, 1997; Kushne & Weinsier, 2000; Siedell & Flegal, 1997 33

Figure 2. Treatment for BMI 19-24.9

BMI19-24.9 BMI19-24.9 BMI19-24.9 BMI19-24.9 WC <102 cmM WC<102cmM WC >102 cm M WC >102 cm M <88 cm W < 88 cm W >88 cm W >88 cm W W/out or less W/2ormore W/out any risk W/2 or more than 2 risk risk factors factors risk factors factors

No Therapy No Therapy Complete PE Complete PE Indicated Indicated Indicated Indicated Monitor Monitor Yearly & Yearly Exercise Stress Test

Determine Determine Goals of Goals of Therapy Therapy

Diet & Exercise Diet & Exercise Therapy Therapy Indicated Indicated Monitor Every Monitor Every Six Months Six Months

Sources: Berke& Borden, 2000; Expert Panel on the Identification, Evaluation, and Treatment of Overweight in Adults, 1998; Han et. aI., 1995; Han et. aI., 1996; Kern, 1997; Lean et. aI., 1995; Lemieux et. aI., 1996 34

Figure 3 Treatment of BMI 25-29.9

BMI25-29.9 BMI25-29.9 BMI25-29.9 BMI25-29.9 WC < 102 cmM WC< 102cmM WC> 102 cnlM WC> 102cmM < 88 cm W <88 cm W > 88 cm W > 88 cm W W/out or < 2 Risk W/2 or more Risk W/out or < 2 Risk W/2 or more Risk Factors Factors Factors Factors

Complete PE Complete PE Complete PE Complete PE Indicated for all Indicated for all Indicated for all Indicated for all groups groups groups groups & & Exercise Stress Exercise Stress Test Test

Determine Goals Determine Goals Determine Goals Determine Goals of Therapy of Therapy of Therapy of Therapy

Diet & Exercise Diet & Exercise Diet & Exercise Diet & Exercise Therapy Therapy Therapy Therapy Indicated Indicated Indicated Indicated As As As As Modified by PE Modified by PE Modified by PE Modified by PE Monitor Yearly Monitor Every Monitor Every Monitor Every Six Months Six Months Three Months

Figure 4 Treatment of BMI > 30

BMI> 30 Regardless of WC Or Risk Factors

Complete PE Indicated & Exercise Stress Test

Determine Goals of Therapy

Diet & Exercise Therapy Indicated As Modified by PE Monitor Every Six Weeks

Sources: Berke& Borden, 2000; Expert Panel on the Identification, Evaluation, and Treatment ofOverweight in Adults, 1998; Han et. aI., 1995; Han et. aI., 1996; Kern, 1997; Lean et. aI., 1995; Lemieux et. aI., 1996 36

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