ACE Study Reveals Power Balance Bracelet to be Ineffective
Posted: Mar 25, 2011 in ACE Press Releases
SAN DIEGO, Calif. (March 23, 2011)—The American Council on Exercise, America’s leading authority on fitness and the largest nonprofit fitness certification, education and training organization in the world, today announced results of an exclusive, peer-reviewed study that found the Power® Balance bracelet did not improve flexibility, balance, strength or power in a series of randomized, double-blind tests. The Council commissioned the exercise and health program team at the University of Wisconsin, La Crosse, led by John Porcari, Ph.D., to determine whether this bracelet enhances and improves athletic performance.
“As the popularity of the Power Balance bracelet has grown, from everyday consumers and gym-goers to high-profile, professional athletes, we recognized that the efficacy of this jewelry should be empirically evaluated,” says ACE’s Chief Science Officer, Cedric X. Bryant, Ph.D. “We ultimately found that the bands had no impact on performance outcomes. Moreover, the significant difference between the first and second time that participants performed tests is likely attributed to participants anticipating the specific test activities the second time around as well as becoming somewhat warmed up, not the bracelet itself.”
The study evaluated 42 college-aged NCAA Division III athletes who were asked to perform two trials of the following four tests, without warm up: trunk flexibility, balance, strength and the vertical jump. Subjects were tested in the same order, but half wore the placebo bracelet in the first trial round, switching to the Power Balance in the second round; the other half first donned the Power Balance bracelet and used the placebo bracelet in the second round. Neither the participants nor the examiners knew which bracelet was used in which trial phase due to the randomized and double-blind exam protocol. In the end, none of the tests demonstrated a significant difference between using the Power Balance bracelet versus using the placebo. The only consistent finding was that the subjects always did better during the second trial, whether they were wearing the Power Balance bracelet or the placebo bracelet.
The first three tests, designed to measure flexibility, balance and strength, were modeled after tests featured on the Power Balance website while the fourth, the vertical test, was added to test the power of the lower body. For the flexibility test, subjects had a stick placed on the back of the neck, across their shoulders, and were asked to rotate as far clockwise as they could with feet placed together; rotation was measured in degrees with a calibrated grid. In the balance test, students stood with feet together, arms extended, and were asked to lift their right foot approximately 15 cm off the ground. Once the subject was in this position, the examiner used a device for measuring force output to push straight down on the right arm as it was extended above ground; the amount of force (kg) required to break the subject’s balance or form was recorded. The strength test asked participants to stand with feet together and arms at side. Examiners then placed the same measurement tool used during the balance test in the palm of each participant’s cupped right hand, and the level of force required by the examiner to push down on this tool and cause the subject to either move his or her feet or break form was recorded. Finally, participants were asked to vertically jump as high as they could from a standing position; their maximal jump height was measured in centimeters. Each test was performed for two trial rounds, with half of the participants in the placebo group for the first round and the other half in the test group.
The most notable improvement was in trunk flexibility across the first and second trial, regardless of whether subjects wore the Power Balance or placebo bracelets. The 9.1 degree increase in flexibility, from an average of 114.2 degree rotation in the first trial to an average of 123.3 degree rotation in the second trial, can likely be attributed to the participants being warmed-up for the second trial. Since practice trials were not provided for any tests, including the balance and strength tests that required an average of 16 percent increase in force and 7 percent more force, respectively, from trial one to trial two, subjects anecdotally replied that they “knew what was coming” in the second trial and therefore compensated by readying their bodies for the tests. Finally, the vertical test improvements, approximately 3 percent, from trial one to trial two were attributed to the subjects being warmed-up for the second trial, further demonstrating that improvement across tests could be attributed to warm-up or habituation to the task.
“The study was designed to test the validity of the claims that wearing Power Balance bracelets with their embedded holograms restore optimal energy balance in the body to improve a person’s strength, balance and flexibility,” Bryant adds. “The bottom line is that after all the data was analyzed, there clearly was no evidence to support the notion that wearing a Power Balance bracelet improves physical performance.”
A complete study summary can be found on ACE’s Get Fit™ website, located at www.acefitness.org/getfit/research.aspx.
The American Council on Exercise (ACE), America’s premier fitness education, certification and training organization, is a nonprofit organization dedicated to promoting the benefits of physical activity and protecting Americans against unsafe and ineffective fitness products and instruction. ACE sponsors university-based exercise science research and is the world’s largest nonprofit fitness certifying organization. For more information on ACE and its programs, call (800) 825-3636 or log onto the ACE website.
Sign up for ACE Press Alerts
ACE Brand AnthemWatch
ACE Logo StoryWatch
Get a more in-depth look at the work ACE has done in the past year, as well as the progress our country has made in responding to the obesity and chronic disease epidemics.View