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You Asked for It: Question Authority

Shook, Robin P. M.S., RCEP; Blair, Steven N. P.E.D., FACSM

ACSM's Health & Fitness Journal: July/August 2011 - Volume 15 - Issue 4 - p 5–7
doi: 10.1249/FIT.0b013e31821ec38b
DEPARTMENTS: You Asked For It: Question Authority

It seems every week I hear about a new fitness trend or exercise product in the news; it can be very confusing. Some of this information seems legitimated, but others seem questionable. How can I determine what is misleading, and what should be done to fight it?

Steven N. Blair, P.E.D., FACSM, is a professor at the Arnold School of Public Health, University of South Carolina. He has conducted research on physical activity and health for more than 40 years. He has published more than 500 articles and is one of the most highly cited exercise scientists, with more than 27,000 citations to his body of work.

Robin P. Shook, M.S., RCEP, is a graduate student at the Arnold School of Public Health, University of South Carolina. He is ACSM Registered Clinical Exercise Physiologist® certified and has worked in exercise physiology research laboratories at Pennington Biomedical Research Center and the Institute for Exercise and Environmental Medicine.






A: In general, the best advice is “If it seems too good to be true, it probably is.” The most appropriate term for these misleading claims is quackery, defined as “medical (or health and fitness) methods that do not work and are only intended to make money” (2). A large portion of health and fitness information presented in the popular media is quackery, which is, at best, misleading and, at worst, fraud.

Unfortunately, there are few sources available to verify the validity of a health claim in the United States. The Netherlands has the Dutch Society Against Quackery, whose sole mission is to combat unproven or fraudulent medical practices (11). With a membership of more than 1,900, the Dutch Society Against Quackery serves as a source of information for the media, the public, and students and grants an annual award called the Master Kackadorisprijs to individuals or institutions making significant contributions to the spread of quackery. Among past laureates is a major Dutch newspaper, health insurance companies, broadcasting companies, an organization funding pseudomedical research, and the author of the book “Medicine in the Netherlands” (11).

Although organizations, such as the Dutch Society for Quackery, attempt to debunk medical quackery, there are few groups that focus on nonsensical fitness claims. In this case, it is up to health and fitness practitioners and consumers to determine legitimacy of health and fitness information. Although this task seems daunting at first blush, there are key strategies and easily accessible resources to help sort through health claims to determine if they are valid.



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The most important step is determining the level of evidence for a claim. Evidence generally can be described as “the available body of facts or information indicating whether a belief or proposition is true or valid” (7).

Evidence comes in many forms and from various sources, each of which should be taken into consideration when evaluating whether a health or fitness claim is true or valid. Perhaps the weakest form of evidence is personal experience. In the fitness setting, just because a certain exercise or product “worked for me” does not translate to universal use by others, given the broad diversity of the participant characteristics (age, medical status, current level of fitness, etc.). This is not to say personal experience has no value in a personal training setting. However, a program based on how one individual gained 25 pounds of muscle on only 5 hours of exercise is likely not generalizable to the majority of the population.

On the opposite end of the spectrum lies scientific literature as summarized in systematic reviews. These reviews use strict criteria to evaluate the entire body of research on a given topic, resulting in evidence-based recommendations for answers to a given question. Recommendations, such as the Physical Activity Guidelines for Americans, are based on these systematic reviews.

An example of how to evaluate evidence to determine validity involves a popular product, performance jewelry. Performance jewelry is currently a common fitness accessory on the market, easily noticed on the wrists of professional athletes and on shelves of sporting goods stores. The Power Balance® bracelet is the most easily identified performance jewelry company, with an impressive list of celebrity endorsers (National Football League’s Drew Brees and Mathew Stafford, National Basketball Association’s Shaquile O’Neal, Derrick Rose, and Lamar Odom, among many others). Performance jewelry claims to improve flexibility, balance, and strength, through devices such as holograms designed to “resonate with and respond to the natural energy field of the body” (9). Demonstration videos are easy to find, displaying individuals performing a test without the bracelet, followed by a repeat of the test with improved results, with the bracelet on.

Researchers at the University of Wisconsin–La Crosse recently tested the Power Balance bracelet using a randomized controlled trial, the highest level of evidence according to the U.S. Preventative Services Task Force, a panel that evaluates medicine products and issues (12). Using 42 collegiate athletes, the researchers tested performance on four different tests of strength, flexibility, balance, and power. The athletes performed each test twice, once with the Power Balance bracelet and once with a placebo bracelet. The order of the bracelets worn was randomly assigned, and neither the participant nor the staff administering the study knew what bracelet the participant was wearing.

The authors found no significant difference in flexibility, balance, strength, or vertical jump height between the Power Balance and placebo conditions (9). In fact, test scores were higher on the second trial for each test, no matter if the participant was wearing the Power Balance or the placebo, suggesting that the results seen in the product demonstration videos were the result of practice or warming up (9).

These same authors have tackled other popular health products, such as toning shoes like the Skechers Shape-Ups®. Shoes of this style claim to “work your hamstrings and calves up to 11% harder and tones your butt up to 28% more than regular sneakers just by walking” (10). The researchers had twelve participants walk on a treadmill at various speeds and inclines and measured heart rate, oxygen consumption, ratings of perceived exertion, and muscle activation while wearing three types of toning shoes, in addition to normal running shoes (placebo). Much like the performance jewelry, none of the toning shoes had improved results compared with the placebo for any variable tested (10).

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As previously mentioned, systematic reviews of the scientific literature represent the best source of evidence to evaluate the validity of a claim. A good example of this is the Physical Activity Guidelines Advisory Committee report, which reviewed existing scientific literature to identify where sufficient evidence existed to develop specific physical activity recommendations. The result was a 683-page document ultimately used to create the 2008 Physical Activity Guidelines for Americans (8). Fortunately, the Department of Health and Human Services (DHHS) created a 1-page desk reference that presents the guidelines for various population groups and the health benefits of physical activity as supported by the scientific evidence (4). In between these two documents in terms of length is the actual Physical Activity Guidelines for Americans (4).

(Note: All documents related to the 2008 Physical Activity Guidelines for Americans can be downloaded here:

Let’s look at a common claim made by many companies that produce performance jewelry, such as increasing muscular strength. According to the desk reference by the DHHS, there is “strong evidence” for physical activity to “improve muscular fitness” (4). More specifically, the Physical Activity Guidelines for Americans state, “Adults also should do muscle-strengthening activities that are moderate or high intensity and involve all major muscle groups on two or more days a week, as these activities provide additional health benefits” (p. vii) (4). Finally, the 683-page committee report becomes even more specific, stating “Progressive, high-intensity (60% to 80% of one repetition maximum) muscle-strengthening activities can preserve or increase skeletal muscle mass, strength, power, and intrinsic neuromuscular activation” based on “Strong, consistent [evidence] across studies and populations” (p. 96) (8). Readers quickly will note performance jewelry is not included in these recommendations for increasing strength.

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The media also play a key role in the perpetuation of health and fitness quackery in our society by promoting claims with weak evidence or reporting single studies that, although they may be legitimate, do not represent the overall body of scientific literature. Although not well studied, there is some evidence to suggest that the public believes that scientists are “always changing their minds” about healthy living advice for cancer prevention, despite little change in the past 10 years in these recommendations (13). Disturbingly, 27% of surveyed participants reported that because health advice always seemed to be changing, the best approach is to “ignore it all and eat what you want” (13).

However, the media also can be a great ally in the fight against quackery. Returning again to the performance jewelry example, the television network ESPN recently ran a report examining the validity of the products, such as the Power Balance bracelet. The show “Outside the Lines” explored the paid celebrity endorsements, sales estimates ($35 million in 2010), and product testimonials by athletes, followed by interviews with the aforementioned researchers at the University of Wisconsin–La Crosse regarding results of their scientific study (5). Television reports, such as this, on high-profile media outlets are excellent examples of journalism that benefits consumers.

(Note: The “Outside the Lines” report can be viewed on the ESPN YouTube channel here:

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When Thomas Wakley founded the well-respected medical journal The Lancet in 1923, he had a mission to furnish people with the knowledge by which they could “detect and expose the impositions of ignorant practitioners” (6). Perhaps it was his experience as a bare-knuckle fighter that motivated him to run a weekly column in The Lancet to expose quacks as profiteers and frauds. It is time for members of the health and fitness profession to take up the fight against quackery in our field, just as Wakley did nearly 90 years ago.

The authors suggest the American College of Sports Medicine take a leadership role in the fight against quackery in the health and fitness profession. A logical initial step is to conduct symposia on the topic at ACSM’s 2012 Health & Fitness Summit & Exposition in Las Vegas and at the 2012 Annual Meeting in San Francisco. It is not feasible for one body to address every charlatan or nonsensical product; indeed, it is the responsibility of promoters of questionable products and ideas to prove their legitimacy. However, the presence of a paragon of truth in the health and fitness profession for which practitioners, consumers, and the media can turn to for reason is needed. Until a professional organization takes up the fight, it will be up to health and fitness professionals to identify pseudoscience, lazy journalists, celebrity experts, and unqualified practitioners as the quacks that they are (1,3).

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4. Department of Health and Human Services. 2008 Physical Activity Guidelines for Americans. Washington (DC); 2008.
5. ESPN. Power Balance Wrist Band — Does it Improve Endurance, Balance and Flexibility or is it a Hoax? ESPN; 2010.
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13. World Cancer Research Fund. Scientists “always changing their minds” on cancer [cited 2011 Mar 20]. Available from:
© 2011 American College of Sports Medicine.