Gina Kolata, science reporter to The New York Times, takes a fascinating journey into the fads, fictions and genuine innovations that have defined the world of physical fitness.

By examining fads through the decades, from weight lifting for men and women in the early days, to jogging, cycling, aerobics, and now spinning, Kolata explains the science of conditioning and the objective evidence behind commonly accepted prescriptions.

Among the questions she addresses are:

• What is the best way to exercise for maximum effect?
• Is there really a "fat-burning zone"?
• Why is that some people won't become fit in spite of exercise?
• Are there foods, drinks or supplements that can help you exercise longer or harder?

Kolata profiles researchers who successfully challenged conventional wisdom and marketed their inventions, and some who resisted initial criticism only to back down from their claims. With lively sketches of many of the mavericks who have influenced the industry, Kolata presents an eye-opening view of the inside workings of a multimillion-dollar business.

Lively and engaging, Ultimate Fitness spotlights the machines and machinations and cuts through the marketing hype, not only to assess what is healthy, but also to understand what our obsession with staying healthy says about American culture today.