It’s lunchtime, and Gayle Goodman heads to the gym in her office tower where she and co-workers at AutoNation spend a half hour sweating through a jam-packed workout with a personal trainer. Then, it’s a shower and back to work. “It’s a quick and effective way of getting in exercise,” she says.

Finding time to exercise is one of the biggest challenges American workers struggle with today. While we know the health benefits, making fitness part of our routine just doesn’t happen for many of us — unless we do it on a job.

Around the country and in South Florida, businesses are stepping in to help employees who lack motivation to exercise on their own. They’re opening on-site fitness centers, creating walk trails and swimming pools, encouraging gym membership, offering lunchtime workouts and even bringing in at-the-desk exercise equipment.

Companies are beginning to realize their employees need help managing stress if they’re going to avoid burnout and stay productive, says Jennifer Owens, editorial director for Working Mother and Working Mother Research Institute. For the first time, the magazine has just published a list of 10 Best Companies for Health and Wellness. At these top companies around the nation, seven feature fitness centers, all offer fitness classes and many have on-site medical clinics. General Mills’ on-site fitness center offers personal training and massages, while Goldman Sachs holds a weeklong program on resilience and health. At Discovery, 65 percent of the workforce participated in a four-month fitness challenge.

“The companies that are successful are getting people to work together to get well,” Owens says. “The hours we’re at work are inching upward. If we can carve out time at work to exercise, that may the answer.”

Even as the economy struggles, corporate gyms are gaining in popularity, with 27 percent of companies in the South either having an exercise facility or giving discounts for employees to join a gym, according to an annual survey of health benefits by Kaiser. That was up from 21 percent in 2008.

For Goodman, an information technology director at AutoNation in Fort Lauderdale, it’s the convenience factor and the enticement of a mid-day stress reliever that lures her to the company’s gym: “Exercise is only an elevator ride away.”

Still, for most office workers, it takes the nudge of a co-worker to get past the psychological barrier that there is no time for exercise. When Jennifer Nash learned her colleagues at City Furniture were doing Zumba, a combination of dance and aerobics, in the conference room twice a week at 5 p.m., she saw an opportunity for a fitness routine that could stick. “I’m down there by 5 and done by 6 p.m. It’s a convenient way to relieve stress at the end of the day.” Weaseling out, she found, was more difficult than blowing off a solo trip to the gym. Throughout the day, emails circulate, rallying co-workers to show up. “We hold each other accountable.” City Furniture last week joined the growing number of South Florida companies opening wellness centers.

Alison Klapper León, director of communications at WorldCity in Coral Gables and a mother of two, says she, too, relies on her co-worker for the will to exercise. “As a mom, it’s hard to put yourself first and take the time to work out.” She and colleague Sari Govantes joined a fitness center in their office building with the intention of going to yoga classes. “When I get busy, it’s so easy not to go. We push each other.”