How Much Sitting is Too Much?

By , SparkPeople Blogger
Several studies in recent years have established that there is a strong connection between how much time you spend sitting and your risk of significant health problems (especially obesity and diabetes) and even premature death. Coach Nancy recently blogged about some of this research here.

A new study reported this week indicates that even as little as a few hours of continuous sitting causes metabolic changes that increase blood sugar levels and decrease the amount of fat used as fuel, therefore increasing the amount that goes back into storage as body fat.

It's important to understand that the issue here is not just that you burn fewer calories when you're sitting around. Long periods of sitting actually cause unhealthy changes in your metabolism.

These studies are showing that extended sitting actually changes the way your body processes glucose and fat. When you are actively moving around, fat circulating in your blood stream will migrate towards active muscles to be taken in and used as fuel. But this study shows that when you are sitting still, the enzyme responsible for taking fat out of the bloodstream and into muscle cells is deactivated, and that circulating fat is instead picked up and stored by fat cells. Researchers injected small amounts of fat into animals that were sitting, and found that it didn't stay in the blood vessels that pass through the muscles. Instead, it was picked up by the fat cells found around internal organs.

Several hours of inactivity reduce the activity of the enzyme lipoprotein lipase, which is responsible for breaking down fat for use as fuel by muscle cells. Researchers did muscle biopsies of sedentary people and found that lipoprotean lipase was suppressed to 10% of normal levels, resulting in fat retention, lower levels of good cholesterol, and a slower metabolic rate.

This study also indicates that even substantial amounts of formal cardio exercise may not be enough to counteract or overcome these negative effects of sitting for long periods of time. Apparently, you can’t make up for sitting for hours at a time simply by making sure you get your 30-60 minutes of exercise every day.

But the good news is that short bouts of physical activity, spread through the day so that they interrupt your sitting time, can help reduce the negative effects of too much sitting. It doesn’t have to be high intensity activity, like formal exercise—simply getting up and walking around the office or the house for 5 minutes every hour can really help.

I don’t know about you, but I’m definitely going to get myself up out of my chair every hour, and do some walking around the house or, better yet, around the block.

How about you? Is it easy for you to get up and do some moving around every hour, or is it a struggle? Got any ideas on how you can squeeze in some physical activity to break up your chair time?

Do you think workplaces, schools and other similar organizations ought to allow and encourage people to get up and move around every hour?

If you're looking for ideas of things you can do during short breaks, be sure to check out some of Coach Nicole's videos in the Fitness Resource Center.