Encyclopedia Britannica will soon cease to exist in print. Many of us grew up with those thick hardcovers, searching for information and answers. Today, at the click of your mouse, we are bombarded with pesky health and exercise claims. Infomercials and manufacturers promise quick and effortless results with the next great gizmo or device, a product that cures a wide range of unrelated diseases, or workouts that burn 1,000 calories an hour. Writer Colum McCann said it's easy to be cynical but much harder to be idealistic and have optimism. Our information age is wondrous, yet a large portion of health and fitness information online and in the media is misleading. If it sounds too good to be true, it probably is. Exercise scientist Steven Blair, a professor at the University of South Carolina, has no problem identifying pseudoscience, lazy journalists, celebrity experts and unqualified practitioners as quacks.
The archaic word "quacksalver" is of Dutch origin, literally meaning "hawker of salve." In the Middle Ages, the word quack meant shouting. The Netherlands has the world's oldest skeptics group, which in 1881 campaigned against misleading medical claims, and today grant awards to the worst offenders. No one is literally shouting at us today, but we can become better advocates by looking at the evidence. Look at high-quality peer-reviewed publications or websites. Strict criteria are used to evaluate the entire body of research on a specific topic, resulting in evidence--based recommendations. The weakest form of evidence, says Blair, is personal experience, in that the broad diversity of an individual's age, medical status and level of fitness need to be considered. Not that personal experience has no value, he notes, but because a certain exercise or product "worked for me" doesn't mean it's well suited for the majority of the population. Some people's success with any given product may be due to a remission in their disease, or from earlier use of medical treatments, rather than the use of the product itself.
Burn 1,000 calories, seriously?
Infomercials are notorious for bold claims, and you've probably heard of cardio equipment that "burns twice as many calories as a treadmill," but are the manufacturers stretching the truth? Dr. David Swain, a professor of exercise science at Old Dominion University, and originator of the VO2 reserve concept for exercise prescription, says believing that you indeed can goes against basic exercise physiology.
The amount of energy used during exercise depends on the amount of muscle mass used and the intensity of effort used with that muscle. Our cardiopulmonary system has an absolute limit on the amount of oxygen that moves from air to our blood to muscles. These increases get incrementally smaller as the absolute VO2 max is approached. For example, Swain sites running uphill on a treadmill as eliciting the highest VO2 of any mode of exercise because all the large muscles of the body are engaged: the legs and hips, and also the back and upper body. Highly trained athletes in Nordic skiing or biking can slightly increase their treadmill value (by 3-5 percent) when performing sport-specific tests. So if a world-class athlete in his or her specific skill gain only so much more, how will the latest claim on some new machine enable you to get twice the results?
"It's not feasible to think that a new mode of exercise can exceed treadmill VO2 by a huge amount," says Swain. Most equipment is similar in its effectiveness if the workload is matched. There's no gadget or machine to replace putting in the time and work to be fit.
www.ncbi.nim.nih.gov/pubmed, a search engine from the U.S. National Library of Medicine and the National Institutes for Health.
Connie Aronson is a health & fitness specialist based at the YMCA in Ketchum.