Being a Couch Potato Just Might Kill You

kaiser permanente study ties physical inactivity to heart disease

The more we learn about our couch potato status, the more dangerous it seems. A new research study has tied sedentary behavior to heart failure in men, regardless of physical activity levels.

The study, conducted by researchers examining the health records of more than 82,000 men 45 years old and over who were part of the Kaiser Permanente California Men’s Health Study, found that those who reported high levels of sitting and low levels of physical activity were more than twice as likely to develop heart failure – when your heart becomes too weak to pump enough blood through your arteries – compared with those who reported high physical activity and low sitting time.

Most of the men were overweight and none with existing heart failure were included in the study. Over a period of 10 years, researchers followed up on the health of the men, who were insured by and received care from Kaiser.

Even those highly sedentary people who exercised more frequently were still at increased risk. Previous studies on the topic yielded similar results. In this study, the men who were most sedentary but also exercised the most were still 1.2 times as likely to develop heart failure as those who exercised at a similar level but sat substantially less.

“Our results strengthen the developing position that too much sitting is detrimental to cardiovascular health, independent of regular physical activity,” the authors concluded. The study was published in the January 2014 issue of the journal Circulation: Heart Failure.

It’s not yet fully understood how physical inactivity affects heart health. Some theories suggest that not using the muscles enough can lead to abnormal blood fat profiles through the suppression of an enzyme called lipoprotein lipase, which converts LDL (bad) cholesterol into HDL (good), among other functions.

To assess sitting levels, the men answered questions such as how much time they spent watching television, using a computer or reading. Their activity level on the job was not assessed. Instead, they focused on the activities outside business hours. Interestingly, they found that those behaviors (beyond the workplace) increase the chances of heart failure.

In an interview on Kaiser’s website, lead study author Deborah Rohm Young said that separating out the people who had heart disease from their sample didn’t impact the relative risk of sedentary behavior and physical inactivity. “It didn’t matter if you had prevalent heart disease or not, the impact of not being active was the same,” she said.

“The message is when you can walk instead of stand, walk,” Young concluded. “When you can stand instead of sit, stand.”