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Researchers cast doubt on manufacturer’s claim of
a 50 percent increase in muscle workout


SAN DIEGO, Calif. (Oct. 17, 2012) – When Fila USA™ began selling its Toning Resistance Tight Capris in 2010 as part of its Fila Body Toning System (BTS), the company claimed the Lycra™-fabric product would yield a “50% increase in muscle workouts” and “41% more support.”


As part of its mission to deliver unbiased fitness information to the public, American Council on Exercise (ACE) commissioned an independent, third-party study to determine what – if any – benefit the pants offered to users.


The study, conducted by a team of researchers at the Department of Exercise and Sport Science at the University of Wisconsin-La Crosse, sought to determine whether Toning Resistance Tight Capris increased muscle activation and caloric expenditure as the manufacturer claimed.


“Consumers are faced with products every day that promise a wide range of fitness benefits,” said ACE Chief Science Officer Cedric Bryant, Ph.D. “We decided to have tested Fila’s claims that this particular product – Toning Resistance Tight Capris – enhanced muscle activation and helped users burn more calories.”


Exercise physiologists began the ACE-commissioned study using a test group of 16 healthy females ranging in age from 18 to 24, all of whom were properly fitted with a pair of Fila Toning Resistance Tight Capris.


During testing, the subjects were required to walk on a level treadmill at 2.5 mph, 3.0 mph and 3.5 mph for 5 minutes at each speed. The sequence was repeated twice; once while wearing toning capris and once while wearing regular athletic shorts. The order was randomly assigned, with each woman being given 5 minutes of rest between sequences.


During each of the exercises, researchers monitored the subjects’ VO2 and heart rate. Electromyography (EMG) electrodes simultaneously analyzed muscle activation of the gluteus maximus (butt), biceps femoris (rear thigh) and vastus lateralis (front thigh) for 15 seconds at the end of each 5-minute stage.


While activation increased significantly in each muscle as the treadmill speed increased, there was no significant difference in the level of activation while wearing athletic shorts or the toning capris. Study participants experienced a modest 2% difference in VO2 and a very small increase in caloric expenditure while exercising in the toning capris.


The increase in caloric expenditure due to the toning capris was about 0.09 kcal per minute, which researchers stated was enough to burn about “half a single Peanut M&M’s®” calorie-wise.


“The results of this study do not support the claims that exercising in these toning pants make workouts more effective in terms of muscle activation or calorie burning,” Bryant said. “But if women want the extra compression and tightness to improve their appearance, that could be another story. Many of the study participants reported that they felt more shapely wearing the toning pants. If looking better makes women more willing to work out, then that’s clearly a good thing.”


To download a copy of the study, visit



About ACE
Since 1985, American Council on Exercise (ACE) has evolved from a small nonprofit dedicated to educating people about proper fitness to a 50,000-strong network of certified Personal Trainers, Group Fitness Instructors (GFI), Health Coaches and Advanced Health & Fitness Specialists (AHFS). As the largest NCCA-accredited nonprofit fitness certification organization in the world, ACE provides quality continuing education to professionals and conducts independent science-based research to protect all Americans from unsafe and ineffective products. Our goal is to inspire people to live their most fit lives through free fitness resources including workouts, nutrition information and expert advice. For more information, call (800) 825-3636 or visit  AMERICAN COUNCIL ON EXERCISE, ACE and ACE logos are Registered Trademarks of the American Council on Exercise.


M&M’S is a Registered Trademark of Mars Incorporated.



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Founded in 1985, the American Council on Exercise (ACE) is a nonprofit organization committed to America's health and wellbeing. Over the past 30 years, we have become an established resource for health and fitness professionals, and the public, providing comprehensive, unbiased research and validating ourselves as the country's trusted authority on health and fitness.

Today, ACE is the largest nonprofit health and fitness certification, education and training organization in the world with more than 65,000 certified professionals who hold more than 72,000 ACE Certifications. With a long heritage in certification, education, training and public outreach, we are among the most respected organizations in the industry and a resource the public has come to trust for health and fitness education.