ST. PETERSBURG — Kerriann Hill isn't your typical coworker.While most people who work at the American Strategic Insurance offices come in wearing skirts, ties or jackets, Hill is comfy in a pair of sneakers, yoga pants and a black zip-up. Her job isn't selling home insurance or explaining flood coverage to potential clients. "They come to me to sweat," she said, while standing near dozens of stationary bikes and treadmills. Her office isn't behind a desk, but on her feet leading classes, like yoga or cycling, and running the 8,000-square-foot gym the insurance company has in its northern St. Petersburg offices.Corporate in-house fitness centers have become increasingly common as companies beef up benefits in the battle to retain employees, but one of the leading companies that creates those programs is right here in Tampa Bay. Hill works inside the insurance company building, but she's an employee of Corporate Fitness Works.The St. Pete business, founded by two women in 1988, has created exercise programs for offices in more than 80 companies and 100 sites across the country."It's so hard to get people together," said Corporate Fitness Works' new CEO Michael Vivio. "How do you truly build a real culture and bonds? You have got to do stuff." Vivio said offices — especially one like American Strategic Insurance that has roughly 900 employees on its campus — can feel like the high school lunch room. Departments tend to stick together, or with whom they work with every day: accounting with accounting, marketing with marketing. But the gym and classes bring people from all across the company together, said American Strategic Insurance executive vice president Kevin Milkey. Whether it be an intense "boot camp" class or a relaxed meditation break."We can be a competitive bunch," Milkey said, laughing. There might be a bench-press contest one week and a three-on-three basketball tournament the next. The gym and classes are just part of the perks Milkey and his team unrolled when the business built its sprawling campus five years ago. There's also outside basketball, volleyball courts and on-campus day care.All of it is free to workers, said Milkey, and seen as a way to retain good employees and keep them happy. He said it's left American Strategic Insurance with low employee turnover. BenefitsPro, a news website for benefit professionals, surveyed its members in 2017 and found 92 percent of the human resource leaders that answered said on-site fitness centers "helped their organization stay competitive."While planning the campus, Milkey was pushing for not only for a workout center, but a knowledgeable staff. He didn't want rows of equipment people didn't know how to use."And if an employee goes in there and hurts themselves," Vivio added, "then everybody loses." The idea of on-campus fitness centers popped up decades ago with a focus on lowering insurance premiums. "Wellness programs" could mean fewer sick days, more productivity.But more and more, research is pointing to how stressed employees are: A Harvard study published in 2016 said 36 percent of workers experience work-related stress that costs U.S. businesses $30 billion in lost work days per year.Vivio — who took over Corporate Fitness works with his wife, Beth Vivio, in August — said the trend is shifting more toward the holistic well-being of employees, even if it can't be measured in precise facts and figures.At the St. Petersburg insurance company, the gym has created something employees can rally around. Hill says whenever she hosts a campus walk or class outside in the courtyard, people peek over the office balcony to watch.At an insurance company, the goal is to get employees up, moving and away from their desks. Because American Strategic Insurance has West Coast clients, people are working all hours of the day, so the gym is open early and closes late. On the weekends it's open, too, and free to family members.At Beall's headquarters in Bradenton, Corporate Fitness Works helped launch a step challenge. In Kansas, the exercise company helped redesign Sprint's 70,000-square-foot facility, complete with yoga, cycling and group class spaces. Inside an auto manufacturing plant, the exercise company has created workouts employees can do in boots and overalls. Vivio said it's not so much one type of industry that seems more drawn to create robust wellness plans."Really," he said, "it's the leadership and those who are thinking holistically about talent." Contact Sara DiNatale at [email protected] Follow @sara_dinatale.