“The one thing that seems to deteriorate quickest with inactivity is insulin sensitivity,” says Ben Hurley, a professor of kinesiology at the university of Maryland at College park.
Type 2 diabetes by far the most common kind occurs when the body becomes insensitive, or resistant, to insulin in the blood. When insulin stops working, blood sugar level rise and diabetes sets in.
Regular exercise reverses the damage.
“It increases insulin sensitivity and makes the cells better at taking in glucose and processing it,” explains I-Min Lee, an associate professor of epidemiology at the Harvard School of Public Health in Boston.
“The data are striking ,” says Hurley. And it’s not just and issue for adults. “Type 2 diabetes used to be a disease of middle age,” he adds. “But now we’re seeing it in young people. It’s a sedentary disease.”
Hurley sounds like researcher Steven Blair talking about the metabolic syndrome, which raises the risk of both diabetes and heart disease.
Doctors diagnose the syndrome when people have a large waist, low HDL (“good”) cholesterol, and elevated (though not necessarily high) blood pressure, blood sugar, and triglyceride.
“The metabolic syndrome is misnamed,” says Blair, who is president of the Cooper Institute in Dallas, Texas. “It ought to be called the inactivity syndrome.”