Extended sitting is dangerous for your health. This conclusion has been around since 2005 when a landmark study established this fact.

Since then, an increasing number of people have begun avoiding the sedentary lifestyle, which includes extended bouts of sitting down, for a more active one involving exercise and more physical activity.

A sedentary lifestyle is a type of lifestyle where an individual doesn't engage in regular physical activity. According to the U.S. Centers for Disease Control and Prevention (CDC), physical inactivity is defined as the failure to meet its recommendations that an individual participate in a minimum of 150 minutes of moderate exercise or 75 minutes of a more vigorous regimen every week.

Walking 10,000 steps a day or 5 miles a week is the ideal goal for improving health and reducing the health risks caused by inactivity, said leading health professionals. Knowing this, however, doesn't seem to have that much effect on people.

The World Health Organization (WHO) reckons 60 percent to 85 percent of the world's population don't engage in enough physical activity. This unfortunate fact makes physical inactivity the fourth leading risk factor for mortality worldwide.

Now, a new study shows how easy it is to degenerate from a healthy lifestyle into a dangerous sedentary lifestyle without even trying. This clinical study conducted in the United Kingdom reveals the ill effects on one's health of only two weeks of sedentary lifestyle.

The study showed that after only two weeks of sedentary behavior, formerly fit people suffered from higher body fat and liver fat, a drop in heart and lung health, a larger waist circumference and higher levels of insulin resistance, which takes place when cells of the body don’t respond properly to the hormone insulin.

Insulin resistance is the key factor leading to type 2 diabetes, gestational diabetes and prediabetes.

Recruited for the study were 28 healthy, regularly active adults, of which 18 were women. The average age of the volunteers was 32.

Their average body mass index (BMI) was just over 24. A BMI under 24.9 is considered normal weight.

Researchers asked the volunteers to drastically limit their activity to an average of just over 100 minutes a day. After two weeks of the couch potato life, the volunteers underwent a battery of tests. These results were compared to measurements taken when the study started.

The study showed the volunteers' cardiorespiratory fitness levels dropped by 4 percent in just two weeks. Waist circumference rose by nearly one-third of an inch. Liver fat rose by 0.2 percent. Total body fat increased by 0.5 percent. Insulin resistance increased while triglyceride (a type of blood fat) levels went up slightly.

"The study showed that two weeks of reduced physical activity -- from approximately 10,000 steps per day down to 1,500 per day -- caused changes in health markers that are associated with type 2 diabetes and cardiovascular disease," Kelly Bowden Davies, study author, said. Davies is a lecturer at Newcastle University and the University of Liverpool in the United Kingdom.

The good news is all this can be undone by returning to your formerly more active lifestyle. The study noted that only 14 days after the volunteers resumed their normal physical activity, these measures all returned to normal.

"It's important to note that when people resumed their normal activity levels after this period, the negative health changes were reversed," Bowden Davies said.

"Even subtle increases in activity can have a positive effect on health. Moving more and breaking up sedentary activity is encouraged."

While both activities are recommended for a healthy lifestyle, it would be ideal to combine the moderate and high-intensity activities. aquachara/Unsplash