This is your body on chairs: Electrical activity in the muscles drops â€” â€œthe muscles go as silent as those of a dead horse,â€ Hamilton says â€” leading to a cascade of harmful metabolic effects. Your calorie-burning rate immediately plunges to about one per minute, a third of what it would be if you got up and walked. Insulin effectiveness drops within a single day, and the risk of developing Type 2 diabetes rises. So does the risk of being obese. The enzymes responsible for breaking down lipids and triglycerides â€” for â€œvacuuming up fat out of the bloodstream,â€ as Hamilton puts it â€” plunge, which in turn causes the levels of good (HDL) cholesterol to fall.