Experts say whether you're pedalling down suburban paths, mountain trails or city lanes, taking a few precautions will have you sitting sweet upon your bicycle seat.

"With the tough economy and gas prices rising, suddenly biking seems like this sensible, fun way to get fit," said Peter Flax, editor-in-chief of Bicycling magazine. "It's cheaper than joining a gym. And you can drive your car less."

In 2010, there were 19.8 million bicycles sold in the United States, up 15 percent from 2009, according to the National Bicycle Dealers Association, a non-profit trade group.

"The biggest surprise is the growth in big and mid-size cities," said Flax. "Go to a coffee shop or a farmers' market, you'll see many people who aren't hard core, spandex-clad athletes using their bikes to get around."

The League of American Bicyclists, an advocacy group, reported that bicycling increased by an average of 36 percent in the 70 largest U.S. cities from 2005 to 2010.

Consequently, Flax said, city biking is getting safer. "Infrastructure changes like bike lanes are on the rise, and people in cars are becoming more patient."

While many a workable bicycle is languishing in a garage or closet, Flax said, before pedalling off into the sunset, or the office, on one, visit the bicycle shop for a tune up and fitting.

"Make sure someone looks at your body. Is saddle at the right height? The handle bars? Someone who has seen hundreds of thousands of people can do a better job than you can do on your own."

If you're in the market for a new ride, Flax says, stick with the specialists.

"Go to a bike shop, not a big box store," said Flax, whose magazine's 2012 Buyer's Guide reviews over 100 bicycles. "Airplane technology has been pushed on to bikes so they are really light and comfortable now."

Another consideration is the ground beneath your wheels.

On suburban trails you want tires wide enough to ride on muck, Flax explained; in the city, the bike should be rugged enough to handle tough pavement; for tooling around the woods, a mountain bike is optimal.

And don't forget the helmet.

"Even at low speeds things can happen," said Flax, who compared riding without a helmet to driving without a seatbelt. "And helmets have gotten a lot cooler looking lately. It doesn't have to be like wearing a giant mushroom on your head."

Bicycling is an effective cardio exercise gets the heart and lungs into shape and exercises large muscle groups, said American Council on Exercise spokesperson Liz Neporent.

"Unlike running or walking, it takes a lot of stress off the joints," she said. "And it's more of a whole body exercise than you would think. There's a lot of core work, and it's obviously great for working the legs and butt."

Neporent recommends supplementing bicycling with strength or resistance training, and urges beginners to start slow.

"You can't undo 10 years of sloth with one workout," she said.

Flax said a brisk ride can burn 500 to 800 calories in an hour, and with the wind in your hair.

"The advantage of biking is how much fun it is," he said. "Compare it to being on a stair climber for 40 minutes."

(Editing by Patricia Reaney and Paul Casciato)

• A Permanent Economic Emergency