Read the passage from "Yes, Sitting Too Long Can Kill You, Even if You Exercise."As total sedentary time increased, so did early death by any cause, the results indicated. And the same was true for longer sitting stretches. Overall then, participants’ risk of death grew in tandem with total sitting time and sitting stretch duration—no matter their age, sex, race, body mass index or exercise habits."We found that there wasn’t a threshold or cutoff where one’s risk for death dramatically increased," said Diaz, explaining that risk of death increased with more sitting. "To give you a specific number, those who sat for more than 13 hours per day had a 2-fold (or 200%) greater risk of death compared to those who sat for less than about 11 hours per day."What is the central idea of this passage?