Chairs: we sit in them, work in them, shop in them, eat in them and date in them. Americans sit for most of their waking hours, 13 hours every day on average. Yet chairs are lethal.
This grim conclusion may surprise you, but 18 studies reported during the past 16 years, covering 800,000 people overall, back it up. In 2010, for example, the journal Circulation published an investigation following 8,800 adults for seven years.