THURSDAY, July 30, 2015 (HealthDay News) -- Sitting too long may be hazardous to your health, even if you exercise regularly, Australian researchers report.

A new study found that sitting appears to be linked to increased blood sugar and cholesterol levels, which can lead to added weight, diabetes and heart ills. But standing more helps improve all these measures and can give you a trimmer waist to boot, the researchers said.

"Switching some of your sitting time to standing could have benefits for your heart and metabolism," said lead author Genevieve Healy, a senior research fellow at the University of Queensland in Herston.

"More time spent standing rather than sitting could improve your blood sugar, fats in the blood and cholesterol levels, while replacing time spent sitting with time walking could have additional benefits for your waistline and body mass index," she said.

However, the study did not prove a cause-and-effect link between standing and walking more and better health.

The report was published July 31 in the European Heart Journal.

For the study, Healy and colleagues gave activity monitors to 782 men and women, aged 36 to 80, who took part in the Australian Diabetes, Obesity and Lifestyle Study.

The monitors kept track of how long each participant spent sitting/lying down, standing, walking and running.

In addition, participants provided blood samples, measurements of their blood pressure, waist circumference, and height and weight (body mass index). The monitors were worn 24 hours a day for seven days.

The researchers found that an extra two hours per day spent standing rather than sitting was associated with approximately 2 percent lower blood sugar levels and 11 percent lower average triglycerides (a type of fat in the blood).

More standing time was also associated with an increase in HDL ("good") cholesterol and a drop in LDL ("bad") cholesterol, the investigators found.

Moreover, replacing two hours a day of sitting time with walking or running was associated with about 11 percent lower average body mass and an almost 3-inch smaller waist.

The researchers also found that average blood sugar levels dropped by about 11 percent and average triglycerides by 14 percent for every two hours spent walking rather than sitting, while HDL cholesterol levels were higher.

"Get up for your heart health and move for your waistline," Healy said.

Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, said, "Many studies have found that the amount of sedentary time is associated with an increased risk of diabetes, heart disease and premature death."

People who sit for prolonged periods have a higher risk of early death, even those who regularly exercise, but the risk is most pronounced in men and women who do little or no exercise, he said.

It's clear that sitting down for too long is bad for people's health, said Dr. Francisco Lopez-Jimenez, a cardiologist at the Mayo Clinic in Rochester, Minn., and author of an accompanying journal editorial.

"As a society, we have been focused too much on exercise and have paid less attention to the importance of just moving," he said.

Lopez-Jimenez said that even if you exercise, sitting for long periods is a marker of a sedentary lifestyle.

Society, he said, values sitting and using labor-saving devices over standing, walking and moving.

"People need to recognize the importance of not sitting too long during the day," Lopez-Jimenez said. "Avoid the mindset that says, 'Do the least amount of effort.'"

More information

Visit the U.S. Department of Health and Human Services for more on decreasing sedentary behavior.