By Anita Dunham-Potter

Travel columnist

updated 12:47 p.m. ET June 13, 2006

When Royal Caribbean’s Freedom of the Seas makes its debut this week, it will not only be the largest cruise ship in the world, it will also have one of the largest spa-and-fitness centers at sea. Add up the 17,089-square-foot exercise area, the rock-climbing wall, the ice-skating rink, the spa and the boxing ring, and you’ll find that the fitness craze has taken over an area roughly the size of a supermarket.

Currently, Cunard’s Queen Mary 2 Canyon Ranch SpaClub is the largest shipboard spa-and-fitness center, coming in at 20,000 square feet. In July, the queen will pass the fitness crown to Costa Cruise Line’s Costa Concordia, whose double-deck spa-and-fitness center will measure 20,500 square feet. The ship will also feature exclusive spa accommodations and spa packages, as well as a specialty restaurant with all spa cuisine.

And it’s not just the new mega-ships. Older ships and smaller cruise lines are chasing the fitness trend, too, making renovations and offering new programs to accommodate passengers’ growing demand for more wellness options — everything from spiritual meditation to Spinning classes.

So, I guess it’s official: Shipboard fitness is big, big, big. Here’s a comprehensive guide to the fitness programs on 16 major cruise lines.

Carnival Cruise Lines. Carnival’s SpaCarnival program dedicates up to 15,000 square feet to health and fitness on each ship, with a variety of ways for guests to pamper themselves. Onboard facilities include the latest workout equipment and aerobics classes as well as relaxation and stretching sessions. Carnival also hosts an annual “Mind/Body Cruise” led by a faculty of experts from Shape magazine and Men’s Fitness magazine. In the dining room, the Carnival Spa Fare menu offers food that is lower in fat, sodium, cholesterol and calories than the food offered on the main menu.

Crystal Cruises. The health clubs aboard Crystal Cruises’ ships are the only spas at sea designed according to feng shui principles. The line hosts several “Health & Fitness” theme cruises each year, with varying emphasis on Pilates, tai chi and yoga. Classes in the fitness centers change daily. Dining venues offer three-course, low-carbohydrate menus and selections that are low in salt, fat, sugar and cholesterol.

Celebrity Cruises. Celebrity’s AquaSpas offer panoramic views of the ocean and include state-of-the-art fitness centers with free weights, advanced weight-training machines, cardiovascular exercise equipment and aerobics areas. The facilities provide trainers for personal instruction. Many of the ships also have AquaSpa Cafes, which feature healthful cuisine for breakfast, lunch and dinner.

Costa Cruise Lines. Costa’s ships offer Pilates and yoga, among other classes. Costa Concordia, which is scheduled to launch next year, is being billed as “the best ship in the Costa fleet for fitness and relaxation.” The big news is the innovative two-deck Samsara Spa, which offers such full-service spa packages as the “Nirvana Ceremony.” The ship also offers dedicated spa accommodations, a collection of 55 staterooms and 12 suites that have direct access to the spa (by private elevator).

Cunard Line. The Canyon Ranch SpaClub aboard Cunard’s flagship Queen Mary 2 features 20,000 square feet of spa, beauty and fitness facilities located on two forward-facing decks. It is the first such facility for Canyon Ranch aboard a luxury liner. To provide guests with a more complete experience, Canyon Ranch chefs have also created a spa menu that is offered in QM2 dining rooms.

Disney Cruise Line. The Vista Spa & Salon fitness center recently doubled in size to include more cardiovascular equipment and weight machines and to provide more space for classes in aerobics, yoga and body shaping.

Holland America Line. Holland America’s Greenhouse Spas offer fitness centers with top-of-the-line weight and cardio machines, as well as Pilates, yoga and Spinning classes. Guests will find healthy meal options on lunch and dinner menus in the main dining rooms and Lido buffets.

MSC Cruises. MSC’s fleet features spas that have a wide variety of fitness equipment along with classes in yoga, Pilates and aerobics. Lunch and dinner menus feature a selection of “Healthy Choice” and vegetarian dishes, including such sugar-free desserts as chocolate mousse and banana cake.

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