Get the skinny on the weight-loss industry

Americans are inundated with promises of quick fixes for weight loss. Ads and articles overwhelm with studies and statistics, many of them contradictory.

Do many repetitions with light weights. Do few repetitions with heavy weights. Eat plenty of carbohydrates. Eat no carbohydrates. Target heart rates, spot-reduction, low-intensity workouts. Perhaps scientists should focus on confusion as a factor for the many American adults who are overweight or obese.

But help is on the way in "Ultimate Fitness: The Quest for Truth About Exercise and Health" by Gina Kolata, science reporter for The New York Times and an exercise junkie to boot.

Certainly, no single book can put to rest all the fraudulent "studies," hucksters and urban legends flying around the fitness industry. But "Ultimate Fitness" is an admirable start.

If only gym memberships came with required reading.

"What can you believe, and how do you know that what you believe is true?" This question is at the heart of Kolata's book, an engaging mix of interviews, anecdotes and history that seeks to separate fact from fitness mythology.

Her skeptical approach is much needed in an industry that has no regulatory body and, therefore, "few bounds."

From scientific studies with no scientific basis to trainers promoting the weight-loss programs that certified them, Kolata reveals how the fitness business, like so many others, is driven by marketing.

Advice is common sense

Her advice, for the most part, is common sense, such as the importance of relying on "research conducted not for marketing purposes but for the purposes of scientific inquiry." Because people are so desperate to lose weight, however, few bother to investigate the "proven guarantees" of regimens and products.

Who among us, for example, has ever questioned the treadmill's heart rate monitor when it informs us that, for optimal results, we must work out at our target heart rates? Who among us has ever questioned their target heart rates?

Kolata, of course, does, consulting experts and examining the history of the heart rate formula, which was developed in 1970. As she documents, it quickly became accepted as gospel, after being "enshrined" in textbooks and, perhaps more important, commercialized.

The reality, according to Kolata and the formula's creators, whom she interviews, is far murkier than any marketing slogan, and includes competing formulas and plenty of debate within the scientific community as to its ultimate usefulness.

Such lack of consensus is typical when it comes to exercise and health -- often, science can neither substantiate nor disprove a given hypothesis.

Kolata's willingness to end her various quests with an acknowledgment of this uncertainty is perhaps the most refreshing aspect of "Ultimate Fitness."

She does draw some definitive conclusions but, as she writes in the epilogue, "My job is just to give you the information that might allow you to think for yourself."