Office workers need to spend less time sitting and more time standing, a growing chorus of experts tells Liu Zhihua.

Sitting kills. Many studies have showed a sedentary lifestyle is a risk factor for many health conditions, including cancer, cardiovascular disease, hypertension and obesity. A more recent study over a 14-year period by the American Cancer Society finds that women who sat for more than six hours a day were about 40 percent more likely to die during the course of the study than those who sat fewer than three hours a day. Men were about 20 percent more likely to die, according to the study. Fortunately, it seems that people are becoming aware of the health risks of extended period of sitting. Some have already adopted healthier poses for work.

Meng Qingguang, 26, founder of a startup IT company in Hangzhou, Zhejiang province, no longer sits at work all the time.

Instead, he spends about four hours a day standing while at work: two hours in the morning and the other two in the afternoon.

"It feels good to stand at work," Meng says, adding that he usually stands for an hour after sitting for similar amount of time.

"Working in the IT industry requires a lot of time sitting before a computer. After a couple of years, you always feel there is something wrong with your body."

Meng has been in the industry for four years, and he notices that senior coders, most of them in their 40s, always seem to have severe occupational health issues, such as indigestion, cervical spondylosis and hemorrhoids.

For Meng, avoiding hemorrhoids and indigestion is all the motivation he needs to stand up at work. He feels better now, he says.

"Our body is not made to sit long," says Qi Qiang, a senior orthopedist with Peking University Third Hospital.

"When you sit, you put immense pressure on the spine. But when you stand up, the pressure will be reduced, and when you lie down, the pressure is the lightest."

Under consistent pressure from sitting, bones, muscles and related nerves will get pressed, strained and even dislocated, causing mild to severe symptoms, including back pain and numbness in limbs, Qi explains.

The cervical and lumbar vertebrae are the most vulnerable spine parts for people who sit for long hours, Qi adds.

"The damage is subtle but it adds up in every second, and such damage can accumulate to a very harmful and even life-threatening level," Qi says.

"It is important to stand up and be active from time to time."

Guo Xiaohui, director of the endocrinology department with Peking University First Hospital, agrees.

Different positions and actions use different muscle groups. When people sit, some muscle groups are relaxed, while others are moving and in use, Guo says.

Guo suggests vanity as well as health should inspire a change in posture. If people keep sitting, he says, some muscles are continuously strained and become damaged, while more others are not getting any exercise - resulting in an expanding waistline and bigger butt.