A review of safe practices and legal standards for training clients with diabetes, metabolic syndrome, hypertension, blood lipid disorders, obesity and cardiovascular disease.
At some point in your fitness career, it is most likely that you will encounter a client with a medical condition, such as hypertension or diabetes. When that happens, whether you are a personal trainer who specializes in chronic disease or a group exercise instructor with one or two special students, you will be held to a higher legal standard of care and professional competency than when you are working with apparently healthy individuals. Consequently, you will need specific knowledge about the governing standards of care and professional competencies required to train clients with special medical conditions.
One means of ensuring reasonable compliance with the required standards and competencies is to be knowledgeable of the consensus standards published by those organizations and agencies with widely recognized and respected expertise in a specific condition. Such organizations publish guidelines and position papers that represent the collective opinions of many physicians, researchers, epidemiologists and educators on issues pertaining to screening and exercise training for those with specific disorders. These documents in their full text provide standards of care to ensure that fitness professionals provide safe and effective exercise while remaining within their legal scope of practice.
Drawing from consensus standards and position papers, this article provides an overview of the salient points for training clients with six of today’s most prevalent medical conditions: diabetes, metabolic syndrome, hypertension, blood lipid disorders, obesity and cardiovascular disease (CVD). Highlighted are the more important issues relating to the diagnosis, treatment and safety precautions for each condition. With one exception, the consensus reports do not quantify the amount or quality of exercise for these conditions, but instead provide important information that should influence exercise assessment protocol and training strategies.
Also summarized are the respective therapeutic (clinical) goals for each medical condition covered in this article. Exercise and dietary therapies, when incorporated as an adjuncts to drug and/or surgical intervention, will increase the likelihood of achieving these clinical goals and therefore are well recognized in the consensus publications summarized in this article.
While it is hoped that this summarization will be helpful for readers, those wanting more information on a particular consensus document are strongly advised to read the entire text for a full understanding of the assessment and evidence-based treatment standards. In many cases, these documents can be downloaded from the organizations’ Web sites at no cost (see “References & Resources” on page 79 for contact information).
Fitness professionals working with clients with type 2 diabetes, the most prevalent form of diabetes mellitus, should have a clear understanding of the American Diabetes Association’s (ADA) Clinical Practice Recommendations. Two of the most relevant position statements contained in this document are “Diabetes Mellitus and Exercise” (ADA 2001) and “Screening for Type 2 Diabetes” (ADA 2000).
The former position statement recommends an exercise intensity that is based on the results of several well-controlled, long-term studies, in which participants exercised at a range of 50 to 80 percent of VO2 max three to four times per week for 30 to 60 minutes per session (ADA 2001). The latter position statement provides the criteria for diagnosing type 2 diabetes (ADA 2000); knowledge of these criteria will help you support the therapeutic goals the physician or diabetes care team has set for your client (see Table 1 below).
Lastly, and most important, it is vital to recognize that, compared with other clients, persons with type 2 diabetes are at much higher risk for other diseases, such as metabolic syndrome (see next section), and most also have coexisting CVD. Therefore, fitness professionals must be judicious and relatively conservative in their initial approach to recommending exercise mode, intensity and duration for clients with type 2 diabetes.
Metabolic syndrome is a cluster of risk factors that strongly relate to both diabetes and CVD. These risk factors include abdominal obesity, hypertension, elevated triglycerides, low HDL (“good”) cholesterol and elevated fasting plasma glucose. The National Heart, Lung and Blood Institute’s (NHLBI) National Cholesterol Education Program Adult Treatment Panel (NCEP-ATP) recently revised its guidelines for screening clients for these risk factors (National Institutes of Health [NIH] 2001); the new screening guidelines, referred to as “NCEP-ATP III,” are outlined in Table 2 below.
Metabolic syndrome may be present with or without diabetes and CVD; the condition is most prevalent in middle-aged men who have become sedentary and gained weight over the previous decade or two. Working with clients with metabolic syndrome represents a tremendous opportunity for fitness professionals to impact health care costs and disability, especially in light of the increasing incidence of type 2 diabetes.
Although no definitive exercise guidelines are available for managing clients with this syndrome, most experts recommend using existing guidelines established for hypertension (NIH 1997) and obesity (NIH 1998). Prior to starting an exercise program that is expected to exceed 60 percent of VO2 max, clients with metabolic syndrome should be screened by a physician and have an exercise electrocardiogram (ECG) test.
Exercise training has also been shown to be effective in managing hypertension. To help mitigate the tremendous health care costs associated with treating this common condition, fitness professionals should be familiar with guidelines established by the NHLBI and contained in The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (NIH 1997). This is one of the most clearly and definitively written consensus reports in all of medicine, and fitness professionals are encouraged to read it in full to understand the applications for working with hypertensive clients.
Table 3 below summarizes the classifications of hypertension, which will help in identifying and reinforcing treatment goals for clients. Understanding the standard cut-points for the different categories of hypertension is also helpful when determining which clients may be most responsive to exercise therapy (usually those classified as having high-normal blood pressure or stage 1 hypertension).
Table 4 opposite provides important components of cardiovascular risk stratification for hypertensive clients. Since hypertensive clients are vulnerable to CVD, their overall risk is determined not only by blood pressure reading but also by other factors, such as damage to target organs.
Based on a physician’s assessment of the risk factors identified in Table 4, a client can be categorized into one of the risk stratifications shown in Table 5 on page 75. For example, clients in Risk Groups A and B who are classified as having high-normal blood pressure or stage 1 hypertension are candidates for lifestyle modification involving exercise, diet and weight management. Moderate physical activity (40%-60% of VO2 max), such as 30 to 45 minutes of brisk walking most days of the week, is recommended for those with high-normal blood pressure or stage 1 hypertension (NIH 1997).
Blood lipid disorders provide an important opportunity for fitness professionals because sufficient exercise can increase HDL cholesterol levels and decrease triglyceride levels. While medications such as statins and fibrates are effective in treating lipid disorders, these interventions are quite costly. The NCEP-ATP III guidelines clearly recommend therapeutic lifestyle intervention as the centerpiece of therapy for the majority of lipid disorders (NIH 2001).
All fitness professionals should become acquainted with the new NCEP-ATP III guidelines for the detection, evaluation and treatment of cholesterol (NIH 2001). Table 6 below summarizes the latest classifications for optimal versus high levels for the entire lipid profile (LDL, HDL, total cholesterol and trigylcerides). Since these guidelines were last issued in 1993, the cut-point for low HDL cholesterol has increased (from < 36 milligrams/deciliter [mg/dl] to < 40 mg/dl), and the cut-point for optimal fasting triglyceride levels has decreased (from 200 mg/dl to ≤ 150 mg/dl) (NIH 2001).
Of the various lipid measurements, LDL cholesterol levels are the most implicated in coronary disease. While the target goals for LDL cholesterol changed slightly in the new NCEP-ATP III guidelines, they largely depend on the individual level of risk. For the majority of adults who do not have diabetes or CVD, the LDL cholesterol goal is < 130 mg/dl (NIH 2001). The goal for those with diabetes or CVD is < 100 mg/dl, which is no small task as it requires a very low fat diet, exercise expenditure > 1,500 kilocalories per week, and in many cases, significant weight loss.
Another new feature of the NCEP-ATP III guidelines is the incorporation of Framingham risk-scoring tables, which identify individuals whose short-term (10-year) cardiovascular risk is sufficiently high to warrant intensive treatment (both pharmaceutical intervention and behavior change); this risk factor assessment is for those without diabetes or CVD but with two or more cardiovascular risk factors. The factors used to score the 10-year risk are gender, age, total cholesterol, HDL cholesterol, systolic blood pressure and tobacco consumption. A score greater than 20 percent (i.e., 20% or more probability of a CVD event in the next 10 years) is considered high risk. Fitness professionals will find these new risk-scoring tables very simple to complete and most helpful in determining a client’s overall risk of CVD (NIH 2001).
In 1998, the NHLBI published its Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity in Adults (NIH 1998). This document contains the most appropriate obesity management strategies, including exercise and obesity assessment. The information is based on a systematic review of published scientific literature from nearly 400 randomized, controlled studies and constitutes the highest standards of obesity management in medicine.
All fitness professionals specializing in obesity should be required to read and apply the applicable aspects of these clinical guidelines. A good starting point, however, is to gain a working knowledge of the NHLBI’s recommendations for assessing weight and body fat (see Table 7 on page 76). Also of particular interest to fitness professionals working with an obese clientele is knowing how to determine waist circumference (see Table 8 on page 76). Another helpful document for working with this population is the NHLBI’s Practical Guide: Identification, Evaluation and Treatment of Overweight and Obesity in Adults, which is a more utilitarian version of the full guidelines. It includes usable sections on obesity assessment; risk evaluation; and dietary, exercise, behavior and drug therapies. The guide can be accessed on the NHLBI’s Web site at www.nhlbi.nih.gov/guidelines/ obesity/ practgde.htm.
The exercise guidelines are more definitive for clients with CVD than for those with the other disorders covered in this article. That is due to the relatively high prevalence of CVD and the plethora of exercise research trials focusing on this disease. Both the American College of Sports Medicine (ACSM 2000) and the American Heart Association (AHA 2000) have published consensus guidelines and position papers on exercise training and CVD. The ACSM guidelines offer by far the more definitive recommendations for exercise testing, exercise prescription and related cautions.
ACSM’s Guidelines for Exercise Testing and Prescription outlines the knowledge, skills and abilities that form the foundation of ACSM’s certification programs (ACSM 2000). Fitness professionals must know how to assess risk and understand the characteristics associated with cardiovascular complications during exercise (see Table 9 below). This knowledge will help you identify clients who require significant adjustments in exercise load, mode and duration and/or clients who require a referral back to their physician.
Table 10 below lists the major issues and recommendation categories expanded on in the full text of the guidelines (ACSM 2000). Before working with CVD clients, fitness professionals should fully understand the scope and application of each of these issues, especially the recommendations as to when a medical examination and exercise testing are required prior to exercise participation. This decision is dependent on the client’s risk status and the expected intensity of the exercise program. Fitness professionals must understand what constitutes low, moderate and high risk and be able to distinguish between moderate (3-6 METs, or 40%-60% VO2 max) and vigorous (> 6 METs, or > 60% VO2 max) exercise (ACSM 2000). It is also important to know and apply the ACSM recommendations for progression to independent exercise with minimal or no supervision (see Table 11 below).
Also pertinent to fitness professionals is the AHA’s Science Advisory Position Paper titled Resistance Exercise in Individuals With and Without Cardiovascular Disease (AHA 2000). Table 12 below summarizes key points from this advisory and will serve as a guide for those performing resistance training with clients who have CVD. Perhaps the most important issues to consider when working with these clients is when to begin resistance training after myocardial infarction and/or open-heart surgery and how to progress exercise load.
Clinical exercise physiologists, exercise specialists, personal trainers and fitness instructors who render exercise-related services to persons with chronic medical conditions are required to adhere to existing standards of care. The position papers and consensus documents summarized here significantly influence these standards of care. It should also be noted that several other organizations publish documents that impact the legal standards of care. These organizations include the American Association of Cardiovascular and Pulmonary Rehabilitation, the Agency for Health Care Policy and Research, and the American College of Cardiology. Refer to their respective Web sites for more details.