By Teri Berg and Paul Suwan

Stair-climbing is one sure way to get in shape, as competitors in the Empire State Building Run-up showed Tuesday. However, fitness experts caution that sprinting up 86 flights of stairs is not for the weak-kneed nor the escalator-inclined.

Whether climbing real stairs or using the Stairmaster at the gym, personal trainer Natasha Roche advises out-of-shape clients to take small steps. "If someone hasn't been to the gym before, they shouldn't spend too much time working out on the stairs," Roche said. "I might start them on an elliptical trainer or the treadmill first." Roche, 29, a fitness trainer in Manhattan and former track star at SUNY-Albany, usually gets new clients walking on a level treadmill or elliptical trainer for 10 minutes, then increases ramp height, speed and time as their cardio fitness improves.

Elliptical trainers work especially well, Roche said, because they are "no-impact" – meaning they don't put stress on hip, knee and ankle joints as much as stair activities do.

Though stair steppers get your heart pumping and strengthen your quads, Roche said people should avoid stair workouts if they have serious knee or hip conditions such as osteoarthritis, a degenerative joint disease that often results from long-term wear and tear.

That advice was echoed in a recent research study at Michigan State University, but with one twist. In comparing stair steppers and revolving stairs to climbing real stairs, researchers discovered a significant difference in the range of motion required of each. That is, step machines allow users to take shallower steps, and thus spare themselves at least some joint stress.

However, if you have healthy joints and want to build muscle and strengthen endurance, study author Nick Alexander said, "It might be more beneficial to climb actual stairs."

There aren't many better ways to get in shape if you can work out on the stairs, said Roche.

"The only way to build muscle better is by weight training," she said.

Still, if overall fitness is the goal, Roche suggests working out on the stairs just two days a week. She said she wants clients to strengthen the whole body, not just the legs.

As for whether it does any good to walk up the escalator rather than ride, Roche shrugged and said, "You've got to start somewhere."

To take on Empire State,
just apply

So you've decided you want to join the stair-climbing masses, lace up your Nikes and dash up 86 floors of the Empire State Building?

According to the New York Road Runners, who sponsor the annual Empire State Building Run-Up, the event is "invitational." Usually, that means a race is reserved for elite or professional athletes who are invited to participate and often paid an appearance fee.

But at least in the case of the Run-Up, anyone can apply to compete. Runners are selected on the basis of athletic ability and background and are notified approximately a month before the race. Those who choose to enter pay a $30 entrance fee.

The only other stipulation the NYRR places on participants is that they must be 18 or older on race day.

Beyond that age restriction, however, the Run-Up typically draws a wide range of participants. This year's field featured competitors from 13 states as well as Australia, Austria, Canada, Germany, Netherlands, Israel, Italy, Japan, Poland, Spain and Ireland.

So if you're feeling like a challenge, fill out an application and start climbing.

—Teri Berg and Paul Suwan