Tim Tyrrell's bosses wouldn't pay for a standing desk, so he took matters into his own hands.

The software engineer in Austin, Texas, used parts from Ikea for a makeshift desk to prop up his keyboard and monitor, letting him avoid the excessive sitting he had heard was bad for him. Other co-workers did the same. His employer at the time, HomeAway Inc., has since relented, converting the office&'s more than 800 desks so they’re now adjustable.

Employers are under increasing pressure to give desk-bound workers more options to get out of their chairs as evidence mounts that sitting for long periods is unhealthy -- even for people who are otherwise in good shape. While the desks can cost thousands of dollars apiece, companies have to weigh the expense against showing concern for employees’ health.

An analysis published today in the Annals of Internal Medicine is likely to give concerned workers more ammunition. Researchers dug through data in 47 separate studies to conclude that longer sitting time was associated with higher risk for death, heart disease, cancer and type 2 diabetes. This can lead to life expectancies that are years shorter, according to David Alter, the paper’s lead author and a researcher at the Toronto Rehabilitation Institute.

Sitting for hours every day was correlated with bad health even for people who exercised frequently, he said. The study didn’t find that sitting caused people to die or get sick, and didn’t seek to explain why there was an association.

“Sitting time was an independent marker of bad health and it was such that sitting time was hazardous to somebody’s total survival,” Alter said in a phone interview. “We need to get off our rear ends and stand up.”

Eight Hours

While the studies in the analysis varied in their definition of prolonged sitting time, Alter concluded that fewer than four hours a day is optimal and more than eight is bad, he said.

It’s enough to give any cubicle occupant pause, but workers like Tyrrell sometimes run into obstacles when they try to persuade employers to purchase equipment to stand at the office.

“They said, ’Well, if we get it for you then we’ll need to get it for 100 people,’” Tyrrell said in a phone interview. After switching to adjustable desks in its Austin office early last year, HomeAway is now planning on making them available at some other locations, said Christina Song, a spokeswoman for the online vacation-rental company.

While 13 percent of companies offered subsidies for standing desks in 2013, that figure reached 20 percent last year and is set to expand, according to the Society for Human Resource Management.

Employer Enthusiasm

Some employers are enthusiastic about the devices. Schermer Inc., a marketing agency in Minneapolis, is pushing to get all of its employees on standing desks soon, and large companies such as Raytheon Co. have made standing desks an option for all employees through its wellness program.

“There was some reluctance -- people thought it was a goofy apparatus to have mounted to your desk,” Chris Schermer, the marketing agency’s president, said in a phone interview. Almost two-thirds of his employees have them now. “Over time their curiosity won out over skepticism.”

Businesses in the U.S. do have obligations to accommodate seating needs of workers with back problems significant enough to be considered a disability, according to Ann Kiernan, a labor lawyer in New Brunswick, New Jersey. But broader rules from the Occupational Health and Safety Administration regulating seating for non-disabled workers were quashed by House Republicans over a decade ago, she said.

Hunched Over

The regulations have made employers willing to find solutions for people with documented ailments. For Chris Blattman, an assistant professor at Columbia University, standing was a necessity. Stressed out and hunched over a laptop for long hours to get tenure, Blattman was having back problems and his doctors said one way to avoid the pain was standing while working. After Blattman submitted his doctors’ papers, Columbia’s human resource department signed off and bought him a desk that cost more than $3,000.

“It was only later that I found out that it was maybe three times as expensive as some of the other solutions,” Blattman said in a phone interview. “I personally think that any of the sit-stand desks would have been completely fine.”

Tyrrell is now working from home for another company. He said his attempts to get his new employer to buy him a standing desk haven’t worked. So this time around, he sprung for an expensive desk -- an electrically adjustable one made by the Human Solution.

“We’re all pretty cognizant that we’re all office drones sitting around all day,” he said. “Anything you can do to improve your health is pretty much a no-brainer.”