Suppose you stick to a five-times-a-week gym regimen, as I do, and have put in a lifetime of hard cardio exercise, and have a resting heart rate that’s a significant fraction below the norm. That doesn’t inoculate you, apparently, from the perils of sitting.
The research comes more from observing the health results of people’s behavior than from discovering the biological and genetic triggers that may be associated with extended sitting. Still, scientists have determined that after an hour or more of sitting, the production of enzymes that burn fat in the body declines by as much as 90 percent. Extended sitting, they add, slows the body’s metabolism of glucose and lowers the levels of good (HDL) cholesterol in the blood. Those are risk factors toward developing heart disease and Type 2 diabetes.
“The science is still evolving, but we believe that sitting is harmful in itself,” says Dr. Toni Yancey, a professor of health services at the University of California, Los Angeles.