Research consistently demonstrates that regular physical activity reduces many of the health risks associated with obesity. Individuals who are overweight or obese but are physically fit and active remarkably have lower morbidity and mortality than individuals of normal weight who are sedentary.14 It is clear that regular exercise and physical activity result in improved fitness and health and need to be foundational elements in addressing obesity in the United States.
Despite national initiatives to reverse the growing problem of obesity in the United States, research shows that less than 43% of adults who are obese are advised to lose weight by their health care providers.15 It is obvious that all health care professionals, including physical therapists, need to more consistently educate patients regarding the benefits of physical activity and weight loss if we are to effectively deal with this growing crisis.
The National Heart, Lung, and Blood Institute (NHLBI) recommends that all health care professionals address risk-factor reduction and weight management strategies with patients who are obese. The NHLBI also advocates the establishment of a modest target weight loss of 10% of body weight, at a rate of 1 to 2 lb/wk. Studies have demonstrated that even modest weight loss results in improvement in or prevention of hypertension, diabetes, and hyperlipidemia.16 Goals related to weight management should focus on achieving and maintaining clinically meaningful weight loss that reduces the risk of obesity-related diseases. The promotion of long-term lifestyle changes in physical activity and diet in conjunction with the establishment of modest weight-loss goals provide a realistic chance of success in combating the obesity epidemic.
An approach to weight loss that combines a restriction of calories with an increase in physical activity and behavior modification has been shown to be the most effective regimen for weight loss, weight maintenance, and improved quality of life.16 Effective behavioral modification programs involve realistic goal-setting, stimulus control, problem-solving strategies, and contingency planning. Self-monitoring of diet and exercise using a journal and enlisting the support of friends and family can be useful in reinforcing positive changes in behavior. Time should be allocated for activities as trying to “squeeze” physical activity or exercise into the day is most often ineffective.
Daily physical activity plays a fundamental role in energy balance, weight control, and overall health. The National Academies Institute of Medicine issued new guidelines in 2002 on nutrition and exercise that recommend that children and adults get a minimum of 1 hour of physical activity daily, twice the previous public health recommendation.17 The new guidelines reflect the need for 1 hour of moderate-intensity physical activity (see Table 16-4) to maintain healthy weight, but recognize that this activity can be accumulated in short periods (minimum of 10 minutes) of activity throughout the day. Research indicates that while significant health benefits can be obtained through participation in at least 2.5 hours of moderate-intensity physical activity or exercise per week, a gradual progression to 3.3 to 5 h/wk facilitates long-term maintenance of weight loss.18 As long-term maintenance of weight loss is the goal for individuals who are overweight or obese, it is important that realistic goals be established and adequate time allotted to gradually progress to this higher recommended level of daily physical activity.
Table 16-4 Indicators of Moderate-Intensity Exercise ||Download (.pdf)
Table 16-4 Indicators of Moderate-Intensity Exercise
55%–69% maximum heart ratea
Borg Rating of Perceived Exertion Scale 12–14 (“somewhat hard”)b
The incorporation of “lifestyle activity” to a weight-loss program can be an effective alternative or adjunct to more continuous, structured forms of exercise. Weight-loss programs of diet with moderate-intensity lifestyle activity have been shown to offer similar health and weight-loss benefits as those of diet with a structured aerobic exercise program.14,19 Participation in moderate-intensity physical activities, such as those listed in Table 16-5, for at least 1 h/d in bouts of 10 minutes or more satisfies the National Academies Institute of Medicine guidelines. Individuals should be instructed to climb stairs instead of using elevators or escalators, perform their own household chores, park in distant parking spaces, get off the subway or bus a stop early and walk the remaining distance, walk during their lunch break, and participate in more physical leisure time activities on a regular basis. Research demonstrates that short bouts of moderate-intensity physical activity performed throughout the day provide an effective way to achieve the recommended quantity of daily physical activity. A comparison of the effects of performing multiple 10-minute bouts of exercise throughout the day with a single, longer bout in overweight subjects revealed greater adherence by those exercising in short bouts, with no negative impact on long-term weight loss or fitness.20,21 Weight-loss programs that incorporate intermittent exercise or lifestyle activity will be more appealing to individuals under significant time constraints or to those that dislike structured exercise programs.
Table 16-5 Examples of Moderate-Intensity Physical Activity (3–6 Mets) ||Download (.pdf)
Table 16-5 Examples of Moderate-Intensity Physical Activity (3–6 Mets)
General health club exercise
Walking 4 mph
Golf (walking and carrying clubs)
Mowing lawn (power mower)
Home repair (painting)
Gardening (weeding and cultivating)
Dancing (disco, folk, line, square, polka)
Golf (walking and pulling clubs)
Raking the lawn
Cycling (<10 mph)
Yoga, t'ai chi, stretching
Fishing (standing in river bank)
Childcare (bathing, feeding, dressing)
Canoeing (rowing for pleasure)
Walking 3 mph
Loading/unloading a car
Carrying small children
Walking the dog
Exercise is a critical component of a comprehensive weight-loss program. It not only increases energy expenditure, but has been shown to diminish the loss of lean body mass and associated decline in resting metabolic rate that is characteristic of dieting alone.22 Exercise improves the body's ability to burn fat, enhancing the loss of adipose tissue.23 In addition, it has been shown to improve dietary adherence while reducing anxiety, stress, and depression that can trigger overeating.24 Research confirms that the combination of diet and exercise results in greater weight loss than diet or exercise alone.25 Periods of severe caloric restriction can result in a significant decrease in metabolic rate that may persist after the dieting period ends, often promoting rapid weight regain. Research has repeatedly demonstrated that daily physical activity and exercise adherence are the greatest determinants of weight maintenance following weight loss.19,20,26
Prior to prescribing an exercise program, medical history, risk factors, and medications should be assessed and when indicated, the patient should be referred to a physician for medical clearance. The Physical Activity Readiness Questionnaire (PAR-Q) has been recommended by the American College of Sports Medicine (ACSM) as a minimal standard for participation in a moderate-intensity exercise program.27 The ACSM has developed risk stratification guidelines based on age, health status, and coronary artery disease risk factors and symptoms that can be utilized to determine the need for a medical examination and exercise testing prior to the initiation of an exercise program.28 Patients who undergo an exercise stress test should have their heart rate parameters incorporated into the exercise prescription. Individuals at low risk can be instructed in self–heart rate monitoring and provided with patient education literature to guide them in progressing their exercise program. It is recommended that health care professionals monitor these individuals periodically to improve compliance and assess progress.
Physical therapists should question patients regarding their previous level of activity, exercise preferences, physical impairments, and time constraints. The type of exercise selected should be pain-free, convenient, and enjoyable to encourage long-term compliance. Whereas home-based exercise programs may improve compliance for some, exercise classes or group settings may provide valuable support and social benefits for others.
Physical therapists can play an integral role in prescribing an individualized exercise program for patients who are overweight or obese. The exercise prescription should include instruction in warm-up, training, and cool-down segments as well as guidelines for progression of intensity, duration, and frequency of exercise. The warm-up and cool-down portion should be designed to address deficits in strength, range of motion, and function that limit participation in activities of daily living, instrumental activities of daily living, and social and recreational activities while also serving to prevent injuries and sudden changes in heart rate and blood pressure. Warm-up and cool-down exercises can include flexibility, active, resistive or balance exercises tailored to address impairments in body structures or function. Flexibility exercises can enhance function, improve posture, and provide greater freedom of movement. Active and resistance exercises can be useful in improving strength and function. An increase in strength that results in an improved level of mobility can promote an increase in daily physical activity. Resistance exercises should target weak muscle groups involved in functional tasks. Balance exercises can be a valuable component of a warm-up or cool-down program and enhance function and safety during gait, reduce the risk of falls, and promote a more active lifestyle.
Individuals who are overweight or obese should be encouraged to gradually increase the intensity of their exercise from low to moderate over time when initiating an exercise program. Guidelines that can be shared with patients to promote an understanding of what constitutes moderate-intensity exercise are listed in Table 16-4. Duration and frequency of exercise should be gradually increased as well, based upon the individual's tolerance and prior activity level. The cumulative effect of exercise over time is substantial and research has demonstrated a clear, dose–response relationship between the amount of weekly exercise performed and the amount of weight lost in individuals who are overweight.29 The most successful exercise programs for individuals who are obese are of moderate intensity, long duration, and are performed frequently.18,30 Individuals should be encouraged to strive for a long-term goal of 60 minutes of moderate-intensity physical activity over the course of each day. An example of an aerobic exercise prescription is provided in Table 16-6.
Table 16-6 Example of an Aerobic Exercise Prescription for Weight Loss ||Download (.pdf)
Table 16-6 Example of an Aerobic Exercise Prescription for Weight Loss
Initial phase: weeks 1–4
Improvement phase: weeks 5–24
Maintenance phase: weeks 25+
Exercise Precautions and Contraindications
Diabetes and hypertension (HTN) are common comorbidities associated with obesity that require special consideration when prescribing exercise. Compliance with a regular exercise program helps to diminish some of the health risks associated with these disease states. For individuals with diabetes, exercise is contraindicated when blood glucose is greater than 300 mg/dL or greater than 240 mg/dL with urinary ketone bodies. Blood glucose should be monitored before, during, and after activity at the initiation of an exercise program, if individuals are taking insulin or oral medications for diabetes. Exercise can lead to exercise-induced hypoglycemia when insulin is available in the bloodstream. A carbohydrate snack may be needed either before or during exercise. It is important to review the signs of hypoglycemia (shakiness, dizziness, hunger, headache, and diaphoresis) in individuals with diabetes. Exercise-induced hypoglycemia can occur up to 4 to 6 hours after the cessation of exercise. Evening exercise should be avoided because of an increased risk of nocturnal hypoglycemia. As the exercise program is progressed, insulin needs may change, so close monitoring and follow-up with a physician is important. People with diabetes are at risk for autonomic neuropathies associated with a blunted heart rate and blood pressure response to exercise and/or silent cardiac ischemia. It is important that heart rate monitoring be performed in conjunction with a rating of perceived exertion scale to determine a safe level of exercise intensity for individuals with diabetes.31
For individuals with hypertension, exercise is contraindicated if resting systolic blood pressure is greater than 200 mm Hg or diastolic is greater than 110 mm Hg. For persons on alpha-1, alpha-2, or calcium channel blockers or vasodilators, the risk of postexertion hypotension exists and the cool-down phase of the exercise program needs to be strictly adhered to.31
Aerobic exercise is the preferred type of exercise for individuals initiating a weight-loss program because of the volume of calories burned and its well-established cardiovascular benefits. Aerobic exercise options include swimming, rowing, upper-body cycles, stationary or recumbent cycles, bicycling, walking or the use of treadmills, exercise videos, or classes. The selection of an appropriate type of aerobic exercise should be based on an individual's preferences, access to equipment, time constraints, and physical factors. In a randomized controlled trial involving women who were overweight, having access to exercise equipment at home was associated with better exercise adherence and weight loss at 18 months when compared with women without home exercise equipment.20
Walking indoors can be accomplished at a local mall or on a treadmill when weather is a factor, or outdoors around a neighborhood or at a local track. Pedometers can be useful in improving compliance and quantifying activity and progress. On the basis of available evidence in the literature, it has been proposed that healthy individuals need to accrue 10,000 or more steps a day to be classified as “active.”32 Home cycle units, swimming, and aquatic therapy are excellent choices for individuals with arthritis as they impart minimal stress to the joints. Indoor pools can be found by contacting health clubs, school districts, Young Men's Christian Associations (YMCAs), or motels for information about pool membership and class availability. Recumbent cycles provide a comfortable alternative to upright cycles. Exercise classes (aerobic, aquatic, yoga, t'ai chi) provide a structured environment with social support that may improve compliance for some individuals. Videotapes (dance, low-impact aerobics, t'ai chi, yoga) are an inexpensive and convenient choice for those who prefer to exercise at home. Health clubs are an option but individuals who are obese must be counseled that exercise equipment such as cycles, treadmills, and elliptical trainers manufactured for the general public tend to have weight limits of 300 to 350 lb. Individuals who are morbidly obese may require specialized equipment to facilitate an increase in physical activity.
It is generally recommended that exercise programs for both weight loss and weight maintenance following weight loss consist primarily of aerobic exercise. There is not always a resistance exercise component. The benefits of resistance training include a reduction in cardiovascular disease risk factors, specifically diabetes, hypertension, and dyslipidemia. Resistance training may have an impact when addressing obesity, general physical inactivity, and predisposing risk factors in cardiovascular disease.16 Resistance training can also assist an individual in leading an active lifestyle by increasing muscle strength and lean muscle mass. Studies that have examined the role of resistance training have demonstrated a reduction in body fat mass and an increase in resting metabolic rates in both men and women. This exercise approach has also been found to increase fat-free mass and resting metabolic rate despite weight loss in postmenopausal women.33,34 Very low-calorie diets have been associated with a loss of lean muscle mass, resulting in a decrease in resting metabolic rate. The addition of resistance training, whether during the weight loss or weight maintenance phase of a program, can counteract these negative results. Overweight and obese persons may better tolerate this exercise modality since it involves slow, controlled movements and the positions can be tailored to the individual for comfort. It is common for obese patients to undertake walking programs, but this activity is sometimes poorly tolerated by weight-bearing joints. The above studies have examined resistance training, but not in combination with aerobic exercise. More research is needed to determine how to structure a weight loss and weight management program in regard to the mix of exercise options. The American Heart Association recommendations for resistance training for persons without cardiovascular disease are as follows35:
- Training at minimum of 2 d/wk, progressing to 3 d/wk
- Training of 8 to 10 major muscle groups including back, abdomen, thigh, lower legs, chest, shoulders, and arms
- Intensity of 30% to 40% of 1 repetition maximum for upper extremities and 50% to 60% for lower extremities; OR, determining a weight that can be lifted for 8 to 10 repetitions and progressing to 12 to 15 repetitions
A resistance training program can be developed in conjunction with an aerobic exercise program and can be progressed at a pace that will not be too overwhelming in regard to the time required for completion.
Health care providers are often reluctant to discuss weight loss with patients who are overweight or obese, but need to address this concern along with the patients' other medical issues. The topic of weight loss can be introduced into the conversation by discussing the benefits of healthy eating and physical activity. Physical therapists can refer patients to nutritionists or weight-loss centers for a dietary plan. If a patient is not ready to seek nutrition counseling, the individual should be provided with an accurate Web site or patient education pamphlet that can be reviewed independently. When raising the subject of weight loss with patients, be clear that the primary interest is in their health and current diagnosis/symptoms; it is not dependent on weight loss during the current episode of care. Patients who are in greatest need for a discussion of weight loss include those with a BMI ≥30 kg/m2, those with a BMI between 25 and 30 kg/m2 that demonstrate two or more weight-related issues (diabetes, personal or family history of cardiac disease, HTN, etc), and those with a waist measurement of ≥35 in. for women and ≥ 40 in. for men.36 Patients need guidance with setting realistic goals for weight loss and a planned progression to increase physical activity without causing injury or exacerbating current musculoskeletal conditions. It is important for patients to gain an appreciation for the impact of small amounts of weight loss on their health. A weight loss of 5% to 10% of initial body weight can significantly lower blood pressure. A weight loss of 5% to 7% through diet and increased physical activity has been shown to delay or prevent the onset of type 2 diabetes in high-risk patients.37
Providing specific information regarding the benefits of weight loss will help make the discussion more concrete. Weight loss will assist in the following ways16:
- Decrease elevated blood pressure
- Decrease elevated blood glucose levels
- Decrease elevated total cholesterol, LDL, and triglycerides
- Increase low levels of HDL
As the plan for weight loss is developed, it needs to be tailored to the individual. There is no set of rules to guarantee success for each person. Including the patient's preferences in the plan will improve the chance of success. Consider cultural issues and other aspects of the patients' health care program that could impact the success of their weight-loss program.
The NHLBI recommends a three-step approach for discussing weight management with patients. The starting point sets the tone for communication. The conversation must be expressed in a nonjudgmental manner. Ask the patients if they are comfortable discussing their general health and include the topic of weight—weight history and the impact of excessive weight on their life. Step 2 is a discussion and assessment of their readiness to make changes in their life. What is their attitude toward exercise and physical activity, and what are potential barriers in this area? Have there been previous attempts to lose weight and increase activity and if so, what approach has been most successful/least successful? Listening to your patients will help you to determine if they are ready for this commitment. Ask specifically about their current perspective on losing weight and improving health on a 1 to 10 scale, 10 being 100% ready for a commitment. Responses between 1 and 4 reveal very little motivation or intention, between 5 and 7 ambivalence, and between 8 and 10 shows readiness to begin a program. The third step creates a partnership with the patients and establishes goals that are reasonable and achievable.38
Exclusions for Weight-Loss Therapy
There are certain patient populations to be excluded from weight-loss programs, and thus should not be counseled during physical therapy episodes of care. These include women who are pregnant or lactating, people with serious uncontrolled psychiatric illnesses such as major depression, those who have comorbidities that would be negatively impacted by a low-calorie diet, and persons having problems with substance abuse.3