Personal trainer Chris Thomas helps John Mallery with his form during a fitness class at the gym of The Metropolitan at Pentagon City apartments in Arlington. (Jason Hornick for Express)

George Bebble, 52, looks and feels better now than he ever did in his 40s. And he can thank his apartment building for that.

Three times a week, Bebble heads down to the aerobics studio on the first floor of The Metropolitan at Pentagon City (901 S. 15th St., Arlington; 703-416-0800) to join 10 or so neighbors in a Pilates class.

Bebble has missed only four classes since he made a commitment to get back in shape on his 49th birthday, and three years of pushups, crunches, leg circles and side planks have paid off. He has lost 40 pounds, and the ol’ aches and pains are a thing of the past.

“The only downside is I did have to buy all new clothes,” Bebble says, “which was kind of nice.”For each of the past five years, D.C. has been ranked the nation’s first- or second-fittest city by the American College of Sports Medicine. Apartment buildings appear to be contributing to the cause. It’s commonplace now for them to include fitness centers, says Doug Bibby, president of the National Multi Housing Council. Many buildings also offer full-on fitness programs with personal training and group exercise classes.

It’s a win-win for the residents and the buildings, says The Metropolitan’s in-house personal trainer Chris Thomas (carefreelifestyle@yahoo.com, 571-550-0221), who managed a Gold’s Gym and a Sport & Health Club before branching off to work at The Metropolitan and other Kettler properties.

Fitness programs are “a great service to [offer] so people don’t feel like they have to go and join a gym,” he says. “Plus, it provides the building a great resource and selling point.”

At The Metropolitan, where rents start at $1,765 for a studio, Thomas provides Pilates and yoga classes on Tuesday nights, Thursday nights and Saturday mornings — $10 for drop-ins or as low as $5 each if you buy a package. The classes are free for those who are in a personal-training program, which costs residents $1 a minute. While most people hit the gym before and after work and on the weekends, personal training is available 24 hours a day. (True story: One guy used to train at midnight when he got home late from business trips.)

At Flats 130 (130 M St., NE; 866-300-2916), where studios start at $1,716, residents can take free Zumba and kickboxing classes twice a week — led by Chickaro Martin and his team of trainers at Project Fitness. The building’s management pays for those two classes, but residents can also pay for personal training and additional classes such as outdoor boot camps. It is not uncommon to see Flats 130 residents running up and down the stairs to the Metropolitan Branch Trail or doing Olympic lifts with weighted bars on a slab of concrete.

Having a full-service gym at home is a big motivator for some residents when the time comes to renew their leases.

“When we think about whether we should move into a basement apartment [in a rowhouse], we’d basically have to tack on a $150-$200 gym membership for me and my fiance,” says Nicolle Kownacki, 30, who has lived at Flats 130 since 2011 and just committed to staying another year. The rowhouses the pair has looked at are priced comparably to what they pay at Flats 130, but they have, unsurprisingly, no gym.

Beyond the monetary savings, sweating through a kickboxing class with neighbors can help build a sense of community.

“It’s a nice sort of social thing to show up early to class and catch up with [everyone],” says Amanda Quemore, 29, who just renewed her lease at Flats 130 for another two years. “At one point, we were talking about having a softball team [for the building]. I think we’re gonna try to pick that up for next season.”

Of course, the obvious benefit in a town where 60-hour workweeks are (sadly) all too common is the time you save by commuting to the gym via an elevator rather than a car.

“Even when I’m working late, I can go home and chill for a little bit,” says Securities and Exchange Commission attorney Dan Greenspan, who trains with Thomas at The Metropolitan. “And then I just walk down to the gym. It’s so easy and convenient.”

Home Stretches

No fitness program in your building? Don’t despair! Companies such as Jones4Fitness (301-648-1372), Lisa Reed Fitness (703-899-9075) and DSM Fitness (202-297-3092) offer personal training in your home, whether you have a gym or not. “We can get pretty creative,” says Jones4Fitness owner Chris Jones. You don’t need a lot of space to do pushups and squats, he says. “I’ve trained people in hallways before.”