In her 20s, Jennifer Alsanady hiked miles and hauled hoses to fight fires in California's wildlands. But in her 30s and 40s, she traded in that physically demanding work for desk jobs, most recently handling insurance claims for Lucile Packard Children's Hospital.

Sitting for much of her eight-hour shift and lounging on the couch when she got home helped add 100 pounds to her 5-foot, 6-inch frame. Her Type 1 diabetes surged out of control. A few years ago, her 53-year-old brother died of a heart attack. Approaching 53 herself, and weighing 250 pounds, she knew she was putting her life at risk.

Alsanady took a first step -- literally. She got on her feet and started to move. These days, when she arrives home after a 45-minute drive from her Menlo Park office, she and her husband go for a walk.

She's made changes at work as well. She never sits at her desk for longer than an hour at a time. She's seizes every opportunity to get out of her chair to talk to a colleague or print a document, and she goes on strolls around the building, sometimes fielding work calls. Between moving more and eating more healthfully, she's dropped nearly 50 pounds.

"Oh my gosh, I feel so much better," she says.

While Alsanady has long lived with the "juvenile" form of diabetes, you could also say she was succumbing to "sitting disease." Scientists writing in the British journal The Lancet call physical inactivity one of the deadliest "pandemics" in our modern, postindustrial society. It is the fourth-leading cause of death worldwide. We've long heard about the health consequences of not getting enough exercise or of kids spending too much time playing video games. What's new is the growing research that points to the dangers of people's overall tendency to be sedentary, notably at work, where people spend many of their waking hours.

One breakdown of an American's typical day shows that people are probably not moving for most of their 13 waking hours, with about two-thirds of those hours -- 7.5 a day -- spent sitting at work. An additional five or more hours are often spent commuting, watching TV, eating and sitting at their home computers.

Meanwhile, science demonstrates that prolonged physical inactivity puts people at risk for everything from increased blood pressure and high blood sugar, to excess body fat around the waist and abnormal cholesterol levels.

"The first problem with sitting is that you're not using much energy to do it," says Joyce Hanna, associate director of Stanford University's Health Improvement Program. "That makes it a lot easier to gain weight and all the health problems that come along with being overweight. Research is also starting to show that sitting too much may also increase people's risk for heart disease and certain cancers.

That's because not moving the big muscles in your legs for hours causes physiological changes in the body, Hanna explains. Blood flow slows, and other metabolic shifts and molecular-level activities subtly and over time increase the risk of the early mortality.

Unfortunately, regular exercise is no longer seen as sufficient to offset these risks.

"It is possible to achieve a high level of activity, such as running for 30 minutes five days a week, but to spend most of the waking hours sitting," Hanna says. "So it is possible to be physically active yet highly sedentary -- an 'active couch potato!' "

Given growing concerns about people's sedentary lifestyles and work habits, the American Medical Association in 2013 called on employers and employees to explore alternatives to sitting, such as standing desks or having employees sit on isometric balls.

Standing or adjustable "sit to stand" desks have become increasingly common setups in Bay Area offices, with the Wall Street Journal calling standing desks the new Silicon Valley status symbol. Also seen in some workplaces: treadmill desks, complete with computer screens and keyboards.

As the founder of Emeryville-based Title Nine, a women's sports apparel company, Missy Park has long blended employee fitness into her workplace culture. A fully equipped 2,200-square-foot gym stands in the center of the company's warehouse-style headquarters, and the 70 employees based there are encouraged to use it at all times of the day.

Still, the one-time Yale University basketball player, who rides an elliptical bicycle to and from work several times a week, admits that she struggles to get away from her desk.

"I am mostly sedentary," Park says. "I'm typical of a lot of my employees. We're very physically active when we're active, but the challenge is how do we get people up more."

Retail operations manager Jill Seiler echoes this view, saying she regularly gets out to boxing classes at lunch and participates in the cross-fit classes offered the company offers on late Monday afternoons. "But I'm at my desk most of the day," she says.

A few employees use standing desks, Park says. She has rigged up an adjustable desk arrangement in her home office, sometimes standing at her laptop set on a high table she bought at Ikea.

Still, Park doesn't see standing desks or other high-tech office equipment as employees' main solution for too much chair time. She looks to find ways to incorporate movement into people's workdays in small, ongoing ways -- similar to what Alsanady started doing on her own.

"We all want that one magic bullet," Park says. "But it's sort like what they say about cross-training. You need to mix it up."

She encourages employees to move out of the board room and hold meetings while taking walks around a nearby park. A year ago, she distributed FitBits to interested employees. These are small wearable wireless devices that measure such data as the number of steps walked. Every few months, the company sponsors competitions using those devices to tally steps taken by employees in different departments. The departments compete against one another to have their employees' combined step totals be the first to reach such figurative destinations as Graceland or the North Pole.

Seiler says she pretty much wears her FitBit daily, even when there isn't a challenge going on in the office.

"I can look at it at 10 a.m. and see I've only done 1,000 steps," she says. "So instead of sending an email to someone in the office, I'll go see them, or I'll take a lap around the office."

Easy Ways
to Cut out CHair Time
At work
  • Set an alarm on your phone or computer to go off every 30 minutes, reminding you to stand up and move around.
  • Cross the office to visit a colleague in person, rather than sending an email.
  • Walk laps with your
    colleagues instead of gathering in a conference room for meetings.
  • Move your laptop around to
    different levels throughout the day.
  • Stand while eating lunch or making phone calls.
    At home
  • Go for a walk when you get home from work instead of sitting down to dinner.
  • Clean or otherwise move around while watching TV.
  • At your kids' sports events, don't sit on the bench; instead, walk around while watching the action.
    Sources: Jennifer Alsanady; Dr. Ann Lindsay,
    professor of medicine and co-director of Stanford
    Coordinated Care; Joyce Hanna, associate director,
    Stanford Health Improvement Program