Forget the Office Gym. Welcome to the Gym Office.

Her new office is the gym, on the fourth floor, in a co-working space scented with notes of bergamot and stocked with a basket of fruit and energy bars.

DiGiovanna, a 25-year-old audit project manager in Arlington, Va., only goes to her real office for big meetings and other organized events. She doesn’t like the isolation of just working home alone, so she signed up for a $499-a-month membership package in July.

The price tag is high, she says, but the setup lets her toggle between self-care and her job, in comfortable clothes, without travel time and lost motivation. It is a third space—not work, not home—that puts her in an energizing environment without having to slog to the office.

“By going into this space and not coming back home, I’m going through these movements of the day more intentionally," she said. “There is less distraction and I’m set up to work more efficiently."

Gyms were once wary of letting the remote-work masses Zoom from their lobbies and locker rooms. Now, they see opportunity in offering extra desks, offices and outlets. Some are creating co-working spaces to separate the extension-cord wielders from the spandex crowd. Other gyms are charging extra and offering entire floors for clients to stay and work all day.

A desk at a co-working space—in which workers from different companies share office space for average monthly fees around $300 to $400 a desk—are facing market tumult. WeWork, once one of the world’s most valuable startups, has raised doubts about its own survival as workers start preferring public space and co-working spaces with lifestyle amenities. Cafes, coffee shops and libraries are often overrun with workers who don’t want to be at home or in the office.

There is appetite for co-working spaces that are close to the places workers already frequent and enjoy spending extra time, like they do at gyms, says Bob Chodos, a vice chairman at commercial real-estate firm Newmark Group, who frequently represents tenants in leasing arrangements that include co-working spaces.

“You’re going to see the evolution of the model accommodate people who don’t want to go into the office but still work closer to where they live," he says.

Gyms as co-working spaces may not be such a heavy lift. Many employees who have the option to work remotely are coming down from their work-from-home highs. While they don’t necessarily want to commute to the office, they crave the buzz of more social environments.

Damaris Hollingsworth, founder of a five-employee architectural firm, says the monthly cost at her Life Time gym’s co-working space allowed her to grow her business, which she began with $475 a month for one desk in 2020. The total cost of her space now—which includes an office and several desks clustered around it—is $4,000 a month.

Hollingsworth, who designs book stores, coffee shops and mixed-use buildings, says she has pondered renting more traditional office space. But the upfront cost of setting up a similarly tastefully-appointed space with all the audiovisual equipment, conference rooms and full kitchen would be too much. Not to mention, her employees might really miss the gym.

“I get to offer an extra perk: If you work for me, you’ll have access to an amazing gym. That is a big deal," she says.

Gym membership levels are still recovering from the pandemic-induced shutdowns, but many say the usage rates have caught up or surpassed pre-Covid levels.

Luxury health clubs such as Biân in Chicago added 9,000 square feet of space for co-working in June. Members who pay annual membership dues of $4,000, plus a one-time initiation fee of $1,000, can access two conference rooms equipped with Zoom cameras and 75-inch TV screens. Other amenities include swiveling chairs equipped with river views and QR codes for food and beverage delivery.

Chelsea Piers’ new 60,000-square-foot location in Brooklyn’s Prospect Heights neighborhood, which opened in June, includes 4,000 square feet of co-working space outfitted with long marble tables, a fireplace and privacy booths.

The company says attendance overall is up 12% compared with prepandemic levels. Chelsea Piers’ other locations are building out similar spaces, says Keeth Smart, a senior vice president. Work tables have been added near patio furniture on the sun deck atop the flagship waterfront gym in Manhattan. Co-working tables and phone booths will be incorporated into new clubs opening next year in Long Island City and Midtown.

“We see throughout the day members are coming, taking a call, hopping into a class, getting back online," Smart says. Keeping people around the gym more of the day has led to bigger spending in the facilities’ cafes and wellness services, too.

Working from the gym can create issues. Jason Shen, a 37-year old executive coach, says he sometimes feels awkward on video calls from the co-working space at Chelsea Piers. The gym is a hive of activity as people walk by in athletic gear. Colleagues on video calls sometimes ask: “Where are you?" he says.

Now, Shen tries to find a neutral backdrop against a wall or in a privacy booth and uses a noise-canceling headset. So far, he says his system works, partly because everyone hasn’t yet discovered that the gym offers co-working.

“In six months," he wonders, “is it going to be overrun?"

Write to Anne Marie Chaker at Anne-Marie.Chaker@wsj.com