Hamburg - The healthy properties of water is ancient knowledge that goes back at least to the Romans.

Vestiges of their thermal baths can be found all over Europe, and people today are rediscovering the meaning of the Latin phrase "sanus per aquam" (health through water).

Wellness travel accounts for 60 per cent of all trips taken primarily for health reasons, according to the European spas association in Brussels. Trips to spas and rehabilitation centres comprise the remainder.

More than any other age group, 35- to 50-year-olds or people who find themselves in the middle of their most difficult work years - increasingly are part of the boom.

"They are well-paid, have little time and therefore seek out effective ways to relax and recover," said Lutz Hertel of Germany's wellness association in Düsseldorf.

But for some people, a wellness vacation is more a question of lifestyle. Wellness currently is chic. Hertel refers to such travellers as people who just use the "infrastructure." They go to a hotel with a large selection of wellness services, sleep late, eat substantial meals and go to the sauna a lot.

The "health conscious" on the other hand have a more structured concept of how the time should be spent, according to Hertel. They want to rectify specific feelings of malaise, are interested in regeneration and desire good advice and medical care. This category of wellness travel is on the rise.

"The tendency is clearly going toward medical wellness," said Joachim Lieber, director of the spas association. This means the vacation is used for a medical examination that the vacationer pays for himself and for therapeutic practices.

There are about 1,200 spas in Europe, according to the spas association. But a wellness traveller may not want to be admitted as a patient, said Christoph Menne, director of the German medical wellness association in Berlin. There are many ordinary hotels that offers services to meet their needs and desires.

"A bathtub in which rose petals are floating often counts as a wellness service," Menne said, criticizing some of the services. He recommends reviewing the hotel's certificates before making a choice and checking out who received them and for what.

Hertel said the "prevention" seal given by his organization is a good clue. The spas association in Brussels and the wellness association in Berlin also issue certificates. In addition, some large travel agencies offer stays in spa and wellness hotels through specific catalogues.

But there are other hurdles to clear when planning a wellness vacation or searching for the right spa.

"It's a bit of an exaggeration, but every indoor swimming pool that heats tap water to at least 30 degrees is described as a spa," complained Horst Jahns, a consultant and author from the German town of Goetschetal near Leipzig. Thus, people who are interested in visiting a spa on their vacation should check to make sure that there is in fact a thermal bath - water that comes out of a natural spring at more than 20 degrees.

Of course, there should be a doctor dedicated to the facility, preferably one who specializes in prevention, rehabilitation or physical therapy, said Hertel.

"In this area, the classic German spas are well established as stuffy and shopworn as they may appear," said Hertel. (dpa)