CHICAGO — At Groupon’s Chicago office, it’s easy to look up to Joel Hadley. During most of his eight-hour-plus workday, Hadley stands at his desk, his head more than a foot above seated colleagues.
Hadley says standing makes him feel alert, focused and energized. He also has less back and neck pain than when he used a chair. But it’s not necessarily the standing that makes Hadley feel better. Instead, the trick may be that the 29-year-old sales analyst rarely sits down.
Thirty minutes of exercise a day used to be thought of as protection against the damaging effects of a desk job. Studies now show that even for those who work out during the day, prolonged sitting can increase the long-term risk of illness or death.
As a result, some office workers are literally standing up for their health – shunning expensive ergonomically correct chairs, building makeshift standing desks and even slowly walking on treadmill desks, also called walkstations.
Hundreds of companies, including Microsoft, Hewlett Packard, Dell and Google, offer employees standing and treadmill desk options. It’s not just a Silicon Valley movement; employees at the Federal Bureau of Investigation, the National Institutes of Health, the Mayo Clinic and dozens of universities have all purchased some form of a standing or treadmill desk.
“In our society, many people are literally living with a stalled metabolic rate similar to an anesthetized patient for over 80 percent of the day,” said inactivity researcher Marc Hamilton, a professor at the Pennington Biomedical Research Center in Baton Rouge, La. “No wonder we have an unsustainable health crisis.”
In the past several decades, increased use of cars, computers and television has contributed to disease, experts say. Some people are either lying down or sitting 20 hours a day, raising their risk of heart disease, obesity, diabetes and some cancers, said Hamilton.
“It was a huge oversight to ever think traditional forms of exercise, such as hopping on your treadmill for a few hours a week, can provide the specific antidote to spending 140 hours a week resting,” said Hamilton, who pioneered the fledgling field of “inactivity physiology.” “Sitting too much isn’t the same as exercising too little.”
Since 2003, several of Hamilton’s studies have found that physical inactivity, such as sitting, can impair key mechanisms in the body that regulate fat and cholesterol metabolism – changes that aren’t reversed by exercise. Sitting also dramatically reduces contractions or electrical activity in skeletal muscles, because the chair is supporting the body’s weight, Hamilton said.
“When you’re standing or walking, your leg muscles are constantly working, which helps to clear glucose and fats from the bloodstream,” said Hidde van der Ploeg, a senior researcher at the Department of Public and Occupational Health and the VU University Medical Center in Amsterdam. “If you’re sitting, this isn’t happening because the muscles aren’t active.”
Even if you’re meeting the World Health Organization standards for 30 minutes of exercise a day, “it’s still important what you do in the remaining hours of the waking day,” van der Ploeg said.
Van der Ploeg’s most recent study, published in the Archives of Internal Medicine, found that adults age 45 and older who sat 11 or more hours per day had a 40 percent increased risk of dying in the next three years compared with those who sat for less than four hours a day.
Though the absolute risk of death was small for everyone, the study showed that “in people who do a similar amount of physical activity, those who sit less will have a lower risk of dying, compared to those who sit more,” said van der Ploeg.
It’s not clear how marathon sitting sessions can increase the risk of death and illness. Hamilton’s research suggests that the loss of muscle contractions that typically occurs while sitting or lying down can suppress production of an enzyme in the skeletal muscle called lipoprotein lipase, or LPL. When lab animals were slightly active, the enzyme was not suppressed, he found.
LPL helps regulate the production of triglycerides, free fatty acids and cholesterol. After a meal, for example, levels of triglycerides and glucose initially rise; then they gradually decline as the body removes and stores the nutrients delivered by circulating blood.
“It’s theorized that sitting may reduce the efficiency of these processes,” said researcher David Dunstan, head of the physical activity laboratory at the Baker IDI Heart & Diabetes Institute in Australia.
“We move from chair to chair throughout the day, from in the home, to the car, at work, to the car and again at home,” Dunstan added. “Sitting less may be at least as important as exercising more.”