For your good health, stand up and take a short walk to avoid significant stretches of sitting. If your work involves sitting at a desk for eight hours a day, which is common today, or whether you favor being a couch potato at home such long periods of sedentary time is associated with greater risks of diabetes, cardiovascular disease and all-cause mortality, as well as colon, endometrial and lung cancers.1-2 Also, contrary to popular belief, one long period of exercise does not combat the dangers of over-extended sitting. A major finding of research on sedentary behavior is that exercising before or after work (although beneficial in itself) does not undo the damage done by sitting all day. So what is a person to do when his or her job demands working at a desk most of the day? The answer is simple: interrupt sitting time with brief exercises or walks may prevent the negative health effects of a sedentary job.
Some interesting results have emerged from studies using short bouts of walking. A relatively short period of sitting—5 consecutive hours (less than an 8 hour work day)-- increased insulin resistance compared to 5 hours of sitting interrupted every 20 minutes with a 2-minute walk.
Participants consumed a 760-calorie meal at the start, completed one of 5-hour patterns, and then the other pattern on the following day. The results showed a more than 20 percent decrease in plasma glucose and insulin levels on the day with walking interruptions.4
Another interesting study compared a single block of 30 minutes of walking to a total of 30 minutes of walking spread out over a day of sitting. In this 2013 study, published in the American Journal of Clinical Nutrition, 70 healthy normal weight adults performed each of these three different patterns in random order:
The participants were given three meals each day throughout the experiment. Regular walking breaks reduced plasma glucose by 37 percent and plasma insulin by 18 percent.
The most notable result from this study was that the regular walking breaks produced greater reductions in plasma glucose and insulin than the 30 minute block of physical activity.5 The important message from studies like these is that even very light activity can help to counteract the dangers of sitting, as long you interrupt your sitting time frequently.