Now's the time to fall into outdoor activities

The weather is perfect, so head for the hills, reach the beach or hit the trails

With vivid colors on the trees and cooling temperatures, fall is a spectacular season for being active outdoors. "No one should feel intimidated by the changing weather," says Barbara Klieforth, president of the board of directors of the Washington Area Bicyclist Association (http://www.waba.org). In fact, exercising without the threat of overheating should be motivation enough. Here are four ways to get your heart rate up outside, with advice on how to stay warm and safe.

SURF After Labor Day, surfers usually don't have to deal with the heavy summer crowds that plague local beaches. Plus, waves are more regular and the water is still somewhat warm along the mid-Atlantic.

There are often four- to six-foot swells "every few days or so versus every week or two, so the waves are more consistent," says Adam Mendizabal, a member of DC Surfrider (http://www.surfrider.org/capitol), a grass-roots environmental organization that includes surfers. That's because of hurricane season and nor'easters from Canada, says Ryan Van Fleet, another member of the group.

Because surf conditions vary with the changing weather and the topography of the ocean floor, it's difficult to pick one spot in the region that's guaranteed to have worthwhile waves. Van Fleet likes Ocean City and Maryland's Assateague Island.

The water temperature isn't too bad, but the wind can make it much cooler, Van Fleet says. So he's usually in a wet suit and brings booties, gloves and a hood to wear in case it gets colder.

It takes upper body strength to paddle and catch those waves. Toning the shoulders and back are crucial, so Mendizabal often goes paddling in the Potomac on his surfboard. "You definitely get a lot of looks when you're walking up the bank to jump in" to the river, Mendizabal says, but it's worth it to get outdoors and in shape for surfing.

ROCK CLIMB This is a vigorous activity that anyone who's reasonably fit can do with the proper training, says Robert Graver, chairman of the Potomac Appalachian Trail Club's Mountaineering section (http://www.potomacappalachian.org): "It's more of a creative expression than a purely physical act."

Fall is when the season winds down for rock climbers, Graver say. It's also when you don't have to worry as much about the heat. "The load gets lighter" in the fall, Graver says, meaning you don't have to carry extra water as climbers do during the summer, though you do need a sweater or shell in case it rains. His favorite sites include outcrops in Shenandoah National Park, such as Old Rag Mountain and Stony Man cliffs. "These offer a little more seclusion," Graver says.

BIKE Cyclists should take precautions in the fall, Klieforth says: "The weather varies not only day by day, hour by hour here, but also from neighborhood to neighborhood." So dress in layers and make sure to attach reflectors or reflecting tape to bikes. If you want to keep clean, use fenders to repel dirt, suggests Greg Drury, chairman-elect of the Potomac Pedalers Touring Club (http://www.bikepptc.org).