Two working women were planning the weekend as they rode the Metro home between snowy Fort Totten and Takoma Station on Thursday.

Movies were out. "I just saw 'Superman' for the second time," said one. "I tried to pretend I never saw it before."

"I've got it," said the other. "Let's rent some gear and go cross-country skiing."

A great idea whose time, unfortunately, had come a few days earlier.

There wasn't a pair of skis left to rent in or around town by then as exercisedstarved Washingtonians jumped on the cross-country bandwagon.

And well they might. Monday's snow on top of eight inches the week before gave the Mid-Atlantic region its first genuine skiing base of the year. "Sold out" on weekend crosscountry rentals, said Appalachian Outfitters and Hudson Bay Outfitters, two local outlets.

"Actually," Linda Sewell at the Silver Spring Appalachian Outfitters store said, "it's been wild the whole month of February. We haven't had anything left over any of the weekends and we even sold out some weekdays."

Okay, what is this sport called cross-country skiing and how has it developed its sudden hold on Washington?

The sport is essentially jogging through the woods with planks on your feet, I found out on a day-long introductory trip with River and Trail Outfitters of Knoxville, Md., near Harpers Ferry.

Its appeal, according to people who do it or are trying to do it, is that it's simple, safe, healthy, inexpensive and it offers snow sport without the complications of downhill skiing.

Howard Lasky, who teaches beginners' classes for Hudson Bay Outfitters, put it this way: "You don't have to go where they have $4 hamburgers, bars, lift tickets, packed slopes and Jean-Claude Killy zebra-striped ski suits."

Which is about how Don Leuchs, his counterpart at River and Trails Outfitters, sees it.

Leuchs comes from New Hampshire and was a pretty fair downhill skier until he got fed up with that scene 10 years ago.

"I enjoy cross-country more because you can get out in the woods alone," he said. "You're not crashed in with throngs of people who are all staring at the equipment you've got and what you're wearing."

But what about the thrills? Isn't cross-country a bit tame?

"I'm still a good downhill skier on cross-country skis and when we come to a good slope I can enjoy that," Leuchs said.

Leuchs has his old downhill skis but years ago he cut the steel edges off them and trimmed them down to cross-country size. He used those skis until this year, when he finally bought a pair of real cross-country skis.

"That's the other thing," he said, "the expense. You can get a complete outfit for cross country -- skis, poles and boots -- for $150, and that's good equipment. You can spend that much in downhill just for your boots, easily."

The only real trouble with crosscountry skiing aroung Washington is the lack of consistently good snow. Downhill ski-area operators can cover a mountainside with snow they make with fancy machines. It's a little harder to blanket a state park or a battlefield so a bunch of people who want to save money can have fun.

"The best cross-country definitely is out in western Maryland," conceded Lee Baihly, who owns River and Trails Outfielders. Until last week, every beginners class his outfit ran had been at New Germany State Park or Blackwater Falls in West Virginia. Both those places are four-hour-plus drives from the Nation's Capital.

"No question," said Baihly. "If you want to cross-country ski you've got to be willing to go where the snow is. And that usually means a long drive."

This week was the exception.Communters glided along Massachusetts Avenue and weekend crowds took to golf courses, parks and anywhere else they could find quiet trails through the snow.

The folks from the Mergenthaler biology lab at Johns Hopkins University in Baltimore took a day off Wednesday and found themselves sharing the trails at Antietam battlefield with a slewfooted outdoors writer.

Leuchs was in charge. After he got us into our boots and skis, he demonstrated the first stationary move, which involved flipping one ski over, putting the second one next to it and then turning around 180 degrees. Seemed simple enough. Everyone tried it and the class collapsed in a heap in the snow.

Things got better. After a lunch of homemade bread, peanut butter, stew, dried apples and carrot cookies, the 15 Baltimoreans found themselves gliding happily along a trail that paralleled Antietam Creek.

The stream was swollen with runoff. As they struggled along on their skis, they could hear the water burbling over the riffles. They saw deer and rabbit tracks down to the water and watched a hawk circle over a field.

"Pretty," said Marilyn Cox. And it was.