It isn't a requirement, but many people sit while watching TV or checking out Facebook. That means, recalling those Nielsen numbers, the average person probably sits around five hours a day — outside of work. This inclination for getting off our feet is killer. All the way back in 2002, the World Health Organization released a statement saying that physical inactivity was a leading cause of disease and disability. Sitting around all day can obviously make a person more likely to be overweight, but it has also been linked to increase chances of developing coronary heart disease, certain cancers, and feelings of anxiety and depression.