DEAR DOCTOR: I always thought standing desks were good for you. Now I read they might not be. Can it really be better to sit all day long? This is an important question to me, because my job is very busy -- and all done from a desk.
DEAR READER: How our lives have changed over the last 30 years. With the incorporation of computers into our everyday tasks, workers are sitting much more than they ever have. In fact, the average person is engaged in sedentary activity 66 to 80 percent of the workday. Add to that the time spent sitting at home while using computers or phones or while watching television, and we have a state in which the average person in the United States is sitting for eight to nine hours per day.
The primary concern lies in the connection between prolonged sitting and obesity and the corresponding connection between obesity and an increased risk of heart attacks and strokes, although sedentary lifestyle is itself a risk factor. Additionally, sitting may place greater pressure upon the lower back than standing, which can lead to chronic back problems, and staring at a computer screen can cause greater neck and shoulder discomfort.
As you noted, some people thought the answer to these problems was a standing desk. For them, the recent study you mention was a disappointment. It assessed the impact on adults, with an average age of 28 years, of two hours of continuous use of a standing desk. After two hours, the researchers measured discomfort in different body parts, actual muscle fatigue (using electromyography, or EMG), and alertness and concentration.
The authors found that, although actual muscle fatigue did not change for the muscles of the lower back and the hips, participants' reported discomfort rose consistently for every body part, especially the lower back, hips, thighs, buttocks, knees and ankles. Further, curvature of the lower spine decreased over the two-hour period, thus putting more pressure on the lower back. Also, the lower legs swelled slightly with prolonged standing, and alertness and concentration declined slightly, which the authors said may have been related to muscle discomfort.
However, the study didn't compare these results to measurements of the same people sitting, so it really wasn't comparing the effects of sitting in a chair against those of using a standing desk. All it showed, in effect, was that detriments can accrue with prolonged standing.
What may be best is a workstation that gives you the option of sitting or standing. A recent analysis combined data from 12 studies assessing the benefits of sit/stand desks. Compared to people who didn't use sit/stand workstations, those who did showed significant reduction in lower back pain. Notably, those studies that allowed people to choose when they wanted to sit and stand showed a greater decrease in lower back pain than did studies that specified a certain amount of time for sitting and standing.
If you're thinking of using a standing desk, consider one that also allows you to sit. This can minimize the problems created by prolonged standing and decrease your chances of lower back discomfort. Regardless of which you do the most -- sitting or standing -- one piece of advice holds true: To minimize strain, take breaks to move around and stretch.
Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles. Send your questions to email@example.com, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.