More and more people are becoming aware of the documented health hazards associated with sitting for long periods of time. Higher cholesterol and blood pressure levels have been linked to prolonged sitting. Cardiovascular disease is twice as common in the most sedentary individuals. There is also increased risk of breast, colon and other cancers, as well as kidney disease. Excessive sitting leads to a decreased insulin response, which means the pancreas becomes overproductive. Prolonged sitting invariably leads to soft abdominal muscles, tight hip and back muscles, and limp glute muscles. During long periods of sitting, blood circulation in the legs slows; this is associated with varicose veins and deep-vein thrombosis. The skeletal system is not spurred to grow denser and thicker while sitting. Sedentary individuals have an increased risk of herniation of lumbar discs. Prolonged sitting can also lead to slow brain performance, neck strain, sore neck, sore shoulders, and rigidity of the spine.

Sitting down for just one hour affects the metabolism in ways that increase adipose (fat) tissue. While standing, individuals constantly burn more calories -- up to 20% more.

Sitting down to work is usually necessary when performing fine motor actions. For example, making a detailed drawing or performing microsurgery will always necessitate sitting. Individuals who must sit at work are urged to periodically stand up and move around throughout the day; such breaks should occur every 20 minutes or so. These micro-breaks heighten comfort and performance and minimize the likelihood of musculoskeletal injury.

Many chair-bound workers think about standing up all day. However, there are problems with excessive standing. It is physically taxing and heightens the risk of varicose veins. Prolonged standing uses the circulatory system more, possibly increasing carotid atherosclerosis. Standing puts strain on the feet.

Workers standing in an ideal ergonomic environment have special anti-fatigue footwear and anti-fatigue mats. There are chairs close by, allowing the employee to sit and rest for a break.

Some workplaces have special sit-stand workstations for computer use. This allows the worker to either sit down or stand up; the special bench is raised or lowered so the computer monitor and keyboard/mouse are always at the desired height. In the real world, a majority of workers unconsciously end up sitting at their workstation most of the time.

Ergonomic and health professionals are currently recommending that all workers take frequent breaks and move around. Variety is the spice of life.