Brianna Knoppow climbs up the escalator at the Dupont Circle Metro station. (kery/Kery Murakami/ For Express)

On most days, and in at least a few stations, you’ll see exiting Metro riders come to a broken escalator. They’ll groan, and then, like Sherpas bearing backpacks and purses, they’ll join the slow-moving procession of people trudging up.

So it seemed unusual how excited Brianna Knoppow was last month when she got off a Red Line train at Dupont Circle and walked to the bottom of the north escalator. She looked up at the 188 feet of stairs leading to an excerpt of a Walt Whitman poem etched on the walls near the top and started climbing.

“I look forward to this," she said.

The escalator happened to be working that day, as are 93 percent of Metro’s escalators at most times, according to WMATA’s figures. But few who come across the 7 percent that are out of service embrace the challenge with Knappow’s enthusiasm.

It all started one day when she was running late and decided to climb rather than ride. “It seemed like a good way to tell if I was in shape, or if I need to go to the gym more,” she said.

Knoppow is a woman in her 30s who, like a lot of people in D.C., has a job with the federal government where she sits behind a desk all day.

“This is my workout for the day,” she said.

Less than a minute later, she stood at the top, panting slightly from scaling what is reported to be Metro’s sixth-longest escalator. “I guess I did OK if I’m still able to talk,” she said. “I did have to unzip my jacket, though.”

For most people who use public transit, getting in a workout isn’t a choice. But apparently all that climbing up and down escalators-turned-stairs, running to catch buses and trains, and schlepping to and from stations is measurably good for them. According to a recent study by the University of Illinois College of Engineering, regular commuters are less likely to get fat than the rest of the public.

Researchers examined health and lifestyle data from 227 counties in 45 states between 2001 and 2009. They found that for every 1 percent increase in the number of people who frequently take public transit, the number of people who are obese in a county dropped by 0.473 percentage points.

That may seem infinitesimal. But given the D.C. area’s population of about 6 million, a 1 percent increase in frequent transit users — about 60,000 people — would mean 28,000 people avoiding obesity.

“When people use public transit, they typically must walk/cycle to the stop/station, and on the back end, do the same," study co-author Sheldon H. Jacobson said via email. “Also, during the transit ride, they may stand (more calories burned). If using a subway like in D.C., the internal walking also adds to the energy expenditure.”

Plus, he added, “No food on public transit means no extra calories consumed during that time period.”

The study reflected others. In 2009, University of British Columbia researchers found that people in Atlanta who used public transit were three times more likely to meet the Canadian government’s recommendation to get 30 minutes of moderate physical activity a day, five days a week than non-transit users.

So maybe we should applaud Metro for trying to keep us in shape?

Rider Matt Garlipp wasn’t buying it.

@wmata both up elevators are not working at Mt. Vernon-Convention Center Metro station,” he complained on Twitter last month. "Nobody working on either one. What’s up?”

He wasn’t ready to applaud Metro after hearing about the study, either. But it did make him think of a joke by the comedian Mitch Hedberg, and a suggestion for Metro.

“An escalator can never break: It can only become stairs," he said. "You should never see an ‘Escalator Out of Order’ sign, just ‘Escalator Temporarily Stairs. Sorry for the Convenience.’”

And not even Knoppow, the enthusiastic elevator climber of Dupont Circle, was willing to espouse the health benefits of coming across one of Metro’s broken escalators.

“Usually,” she said, “my first thought is, ‘Really Metro!? Another broken escalator?’”