I am the poster child for this study's conclusion. In the first study that used a thigh-worn activity monitor to truly track sitting time, they found that women who got the recommended 10,000 steps per day and 150 minutes of moderate-intensity physical activity per week still spent most of the day sitting and inactive. They spent an average of nine hours per day sitting, which is more time than most people spend sleeping.
This is bad because several studies show that sitting time increases your health risks, whether or not you get enough physical activity the rest of the day. The conclusion of the study is that you can't judge whether someone is inactive based on how long they spend sitting. Women who get much more exercise than the average person still spent nine hours a day sitting still. It's going to take more than encouraging physical exercise to reduce sitting time. It's probably going to take redesign of the workplace, with standing desks and workflow that gets people out of their chairs and cubicles.
I have a FitDesk bicycle desk in my home office and I have to admit that it is functioning as a clothes hanger at the moment. Time to start using it!
Source: Lynette L Craft, Theodore W Zderic, Susan M Gapstur, Erik H VanIterson, Danielle M Thomas, Juned Siddique and Marc T Hamilton. "Evidence that women meeting physical activity guidelines do not sit less: An observational inclinometry study." International Journal of Behavioral Nutrition and Physical Activity. 2012, 9:122 doi:10.1186/1479-5868-9-122