For today’s cruisers, deck chairs are not sports gear of choice

Two young men are crawling up a glacier.

“Leave me. Go on,” one implores.

“I am not leaving you behind, man,” the other says, grabbing his companion’s collar.

Then comes the clincher: A woman’s voice says, “If you guys don’t quit it, I’m going to miss my massage,” as the camera pans out to show a gentle incline.

This recent TV spot from Royal Caribbean International, with Iggy Pop’s “Lust for Life” blaring, is the latest salvo in cruising’s campaign to shed its sedentary image and get younger people aboard.

Those 25 to 44 are in “an age group that the industry is desperately trying to reach out to,” says Sharon Dodd, editor of www.cruisecritic.com, a cruise information Web site. That’s because first-time cruisers tend to be in that group, she says.

The effort seems to be working. The average age of cruise passengers has fallen from high 40s to low 40s on Royal Caribbean in the last three or four years and from 55 to 51 on Princess Cruises since 1998. There are also more families and more repeat cruisers looking for new activities, the companies say.

Happily for the sports-minded, these trends have produced an abundance of hiking, bicycling, skating, snorkeling and other active options on board and on shore excursions.

When Royal Caribbean’s Monarch of the Seas begins three- and four-night Mexico cruises June 6 out of Los Angeles, it will offer a rock-climbing wall and more cardio equipment geared to the health-conscious West Coast.

By the end of this year, Royal Caribbean’s entire fleet will have rock-climbing walls, which the line introduced in 1999 on its Voyager of the Seas.

While Royal Caribbean is out front in on-board athletics (and also offers many active excursions, including glacier treks), Princess Cruises is a leader in sports-minded shore trips, industry observers say. This season, Princess offers 125 Alaska shore excursions, more than 20% of them active trips, says spokeswoman Julie Benson.

Sorting through the options can be confusing. Princess’ Alaska shore excursions catalog is 119 pages long. Dozens more tours that run from the line’s lodges have their own catalog.

I asked several experts for tips on how to arrange athletic shore excursions. Here’s what they told me:

Evaluate your fitness and finances: Be honest with yourself. “If you have trouble walking around the block, hiking a glacier may not be for you,” says Dodd of Cruisecritic.

Cruise lines’ catalogs typically use symbols to rate a trip’s difficulty. Carnival Cruises, for instance, offers four ratings: easy (involving short walks over relatively even surfaces), moderate (fairly active with some uneven surfaces, stairs etc.), considerable (requiring constant effort, such as paddling) and extreme, a new rating available only in Alaska for the most physically fit. A five-mile snowshoe trek falls into the last category.

It may help to have a healthy bank account too. Although some active excursions are modest, costing $40 to $60 per person, others may run $200 or more. Princess’ popular dog sledding and helicopter trip is nearly $400 per person.

Get the details: Kayaking may conjure up images of effortless gliding along placid waters. The reality may be far different.

Last Thanksgiving, Mike Driscoll, who edits the trade newsletter Cruise Week, took a cruise line’s half-day kayak trip through mangroves in the Key West area. It was windy, and the going was tough.

In the end, “I was exhausted, but I enjoyed it,” says Driscoll, who is 43. Several paddlers in their 70s, however, “were just wiped out,” he recalls. “For them, it was a disaster.”

Don’t rely just on the cruise line’s trip ratings or your experience with a sport. Before booking, contact the cruise line (or ask your travel agent to do so) and ask for specifics. Will you need to paddle the kayak or canoe constantly for several hours? What’s the vertical gain on the hike? How many miles will you be bicycling?

Fitness fiends may want to make sure the trip is strenuous enough. Some excursions billed as “active” may involve little more than getting off a bus and taking a long walk. In some cases, cruise lines “just use more ecological terms for things they’ve been doing for years,” Driscoll says.

For participants’ candid first-person accounts, Dodd suggests visiting Internet chat rooms and message boards. Cruisecritic .com and www.cruisemates.com are among sites that host these.

Book early: If your heart is set on a particular shore excursion, it may be wise to book before you board the ship. That’s because active trips are often the first to sell out.

At Princess, passengers can reserve a place on excursions up to four months in advance, says spokeswoman Benson. At some lines, including Princess (at www.princess.com), you can even book them on the Internet.

If you’re shut out of a trip, don’t despair. Check the wait list when you board. Typically passengers can cancel up to 24 hours before an activity begins, so spaces may free up, Dodd says. (Check each line for its policy.)

Buy insurance: If you’re taking an active shore excursion, Dodd advises buying third-party medical insurance that covers medical evacuation, especially if you’re going to a foreign country.

If you’re disabled by an injury on land, “the ship isn’t going to wait for you,” she explains. Medical insurance is probably also a good idea even if you plan only on-board sports such as wall climbing and inline skating.

Don’t rule out the independent route: Arranging excursions directly with local tour operators instead of booking them through the cruise line will often save you money, Dodd says. But doing so may require careful research to verify whether the tour operator is insured or bonded and properly certified.

By studying up on the destination, you can also plan your own hiking or biking adventures.

Just make sure you have enough time in port to get back to the ship before it pulls away -- or you may end up missing more than a massage.

Jane Engle welcomes comments and suggestions but cannot respond individually to letters and calls. Write Travel Insider, Los Angeles Times, 202 W. 1st St., Los Angeles, CA 90012, or e-mail jane.engle@latimes.com.