Photo: Courtesy of Hachette Book Group, Inc.

You may have heard of Zumba -- a.k.a. the Latin dance-exercise craze that's taking over a fitness center near you, or perhaps your very own DVD player. Now there's a new component (available in stores September 10, 2009) -- a book with workouts, diet plans, menus and recipes, along with an instructional DVD, plus a "5-Day Express Diet." Beto Perez, Zumba founder and celeb fitness guru, says that even his dance exercise routine needs the other key component to weight loss, watching what you eat, as "the symbiotic relationship between diet and exercise is the secret to weight loss success." Below, Perez and co-author Maggie Greenwood-Robinson, explain how fitness newbies and know-it-alls alike can benefit from Zumba and if losing nine pounds in five days, like the express diet claims, is really safe.

That's Fit: What separates Zumba classes and workouts from other routines?

Beto Perez: One word -- fun. Most people who begin taking Zumba used to hate exercising. Because they enjoy and look forward to their Zumba classes, it makes it much easier to stick with it. There is also a lot of variety involved in Zumba because of all the different dance styles used from merengue and salsa, to rumba and reggaeton.

That's Fit: How can more serious athletes and gym rats benefit from Zumba workouts?

Perez: Even serious athletes can benefit from a change in their routine and using muscles they usually don't work out. Zumba has a lot of core and oblique work, muscles that are sometimes neglected. Zumba burns as many calories as any other intensive group exercise class.

That's Fit: Can you explain the "5-Day Express Diet" and how its claim of "losing up to nine pounds in five days" can be healthy?

Maggie Greenwood-Robinson, Ph.D.: The "Zumba 5-Day Express Diet" is a tool to give you a jump-start on weight loss. It does take pounds off quickly -- a benefit that is a motivator to dieters. Many people find that losing a lot of pounds initially provides an incentive to stick with a more moderate weight-loss plan like the Zumba Diet. You can also use the "5-Day Express Diet" to break a plateau or lose a little extra weight for a special event. Some of your weight loss on this diet will be water, but seeing a drop on the scale -- water or fat or both -- is definitely a motivator.

When followed on a short-term basis (no more than five days), the "5-Day Express Diet" is healthy. It does allow for lots of vegetables and fruits -- which most people should be eating anyway -- plus protein and other natural foods. When people have followed this diet, they have lost up to nine pounds; some lose less, like two pounds. Keep in mind that some of the loss is water, but cosmetically, water weight can hide fat loss and be particularly frustrating. Fluid retention is never good, because it puts a strain on the body. So losing water weight is beneficial.

Learn more about water weight -- and how to lose it -- at AOL Health.