On a chilly December evening, Steve Shaffer was working up quite a sweat.

On a chilly December evening, Steve Shaffer was working up quite a sweat.

A member of the Columbus Curling Club, Shaffer was "sweeping" the ice, helping guide the stone down the long, slippery corridor.

"There's a lot more skill involved than one would think," the 51-year-old Upper Arlington resident said.

Shaffer is one of thousands of central Ohio residents who participate in non-traditional indoor sports during the winter. He's a five-year member of the curling club, which recently moved into a facility at 2999 Silver Drive in the Clintonville area.

The interior temperature hovers around 38 degrees, but it's still better than a frozen loch in Scotland, where the sport is believed to have been invented in the 16th century.

"It's cold in here but there's no wind. So playing outside on a pond, I can't imagine," said Shaffer, a scientist at Battelle who interestingly enough has a degree in tribology, the study of friction, among other things.

Treadmills bore you? Martial arts make your knees hurt? Aerobics classes take the wind out of your sails?

Some say the best way to exercise is when you don't realize you're doing it.

Lunging and parrying suited Jonathan Dunkin just fine.

Wanting to be more active and romanticizing the swashbucklers of yore, Dunkin took a fencing class offered by Julia Richey, coach at the Royal Arts Fencing Academy in New Albany. Classes are held throughout greater Columbus. Introductory lessons are $75 for six sessions, with fencing equipment provided on each visit. Private lessons cost $50 each.

"It was just something interesting to do, unique compared to other things," he said.

A year later, the 25-year-old is teaching entry-level foil. He likes the individual-achievement aspect of fencing.

"It's fun working on a team but it's also fun to go at it on your own and see how you do," he said. "You have to have your own skill. In teams sports you can rely on team members to catch you."

Richey, a 25-year veteran of the sport and once a member of the Russian National Team, said fencing combines athletics, grace and intelligence.

"First of all, this sport is for any age," she said. "It's a life-skill sport. It's for people who like to think while they move. And it is a year-round sport."

The climate-controlled atmosphere at Vertical Adventures makes it an ideal place to learn the basics of rock-climbing, founder Alex Roccos said.

Set in an industrial warehouse at 6295 Busch Blvd. in Northland, the school offers instruction for all ages and levels of competence, Roccos said.

"You're able to learn how it all works," he said. "Everything that you learn indoors translates into outdoor climbing."

An introductory class includes a lesson, plus rented equipment (special shoes and a harness), for $25.

The walls at Vertical Adventures are 12 to 25 feet tall stuck with protrusions and can lean 30 to 70 degrees off vertical. To some, it's more than a climbing wall, it's a chess game that requires agility, strength and thought. And it burns 14 calories a minute, according to Roccos' calculations.

"It's kind of a whole-body thing," he said. "It's definitely not riding a treadmill. You have to pay attention."

Julie Smith, a former gymnast, said women shouldn't be intimidated from trying the activity.

"People are really impressed because women tend to excel at certain kinds of climbing," said the 27-year-old Victorian Village resident.

Sometimes exercise isn't what people have in mind. And their activities might not even be above the ground.

At Aqua Immersion Dive 'N Travel, the fun takes place under water. The most popular training, not surprisingly, is open-water certification. For $404, the business teaches the fundamentals of scuba diving in two 12-hour sessions, one involving classroom study, the other dealing with the underwater aspect of the sport, said the store's co-owner, Melissa McCurry.

The store, 929 Jasonway Ave. on the Northwest Side, is furnished with a 6.5-foot-deep pool. However, the third part of process must be done in a natural setting.

Aqua Immersion also teaches underwater photography.

"Entering the digital age has made it less expensive and easier to operate a camera and has really given a purpose to diving," said Dr. Mark Fulton, a partner at Aqua Immersion and a photography instructor there.

The session, which costs $125, teaches the basics, such as lighting, focus and digital post-processing, said Fulton, a neurosurgeon at Riverside Hospital. The store sells camera equipment, which costs extra.

"Right now, the imaging is really driving the diving industry more than just about anything else," he said.