Kids, as the say, are the future. So perhaps it should come as no surprise that cruise lines are lavishing more attention than ever on the little ones. Still, yoga for kids?

That’s the Big New Thing this week at Princess Cruises, which announced it is rolling out what it bills as the industry’s first yoga program for youngsters.

The free classes will debut fleet-wide this fall and be open to children as young as three years old. The classes will take place in the children’s areas of Princess ships instead of the fitness area where most yoga classes are held, but Princess says parents are welcome to join in with their kids during the sessions. The classes will last 30 minutes to an hour.

The new yoga-for-kids program comes as Princess beefs up other areas of its fitness program. The line also announced this week that it is adding what it calls the first industry’s first in-room fitness classes — a Princess-produced morning fitness program shown on cabin TVs. Led by celebrity trainer Gillian Clark, the program also will be shown on the big outdoor Movies Under the Stars screens found on some Princess ships so that passengers can work out in a group setting.

Princess also is bringing Nintendo Wii Fit balance games to its ships (with poolside competitions planned on the big Movies Under the Stars screens). screens.

Just this week, of course, Royal Caribbean announced plans for an entire spa area devoted to kids on its next ship, the much-awaited Oasis of the Seas.