Why exercise can´t undo the consequences of sitting

Why Exercise Can´t Undo the Risks of Sitting

The WHO recommends 150 minutes of training per week - about 20 minutes per day. Is that enough to stay healthy if you spend the rest of the day sitting? New study results on this will probably surprise you.

People with office jobs spend about two thirds of the day sitting. In addition to the hours spent in the office, there is time in the car, during meals and quickly a few more hours of "screentime".

The fact that sitting for long periods of time without interruption day in, day out is not healthy is something we have known at the latest since "Sitting is the new smoking". Those who spend most of their time in a chair every day not only get back pain in the long run, but also dramatically increase the risk of many civilization diseases such as diabetes, heart disease, stroke, cancer, depression and dementia. [1][2][3][4]

Meet the Active Couch Potato

What about those who lace up their running shoes 3 or 4 times a week after work, or who go to the gym or yoga studio, the so-called "Active Couch Potatoes"? An American study [5] has investigated how regular exercise, with otherwise sedentary work, affects premature mortality, heart disease, cancer and diabetes. The conclusion was that time spent sitting is an independent risk factor and cannot be compensated by exercise.

A study [6] of 220,000 Australians came to very similar conclusions: life expectancy was shorter the more time was spent sitting - again independent of other sporting activities.

Not made for sitting

How can this be explained medically? Why does sitting make us ill and why can't even daily intensive sport change this? Evolutionary biologists agree that our nomadic ancestors spent only about three hours a day sitting. Technical simplifications, motorized transport and desk work have only made sedentary everyday life the undisputed status quo for about 150 years. With this rapid change, however, our genes programmed for movement and thus our metabolism and musculoskeletal system are hopelessly overtaxed.

When sitting, the muscles, especially in the legs, are more or less inactive. This increases the blood sugar level and slows down the blood flow. After only a few minutes, the activity of an enzyme that increases the level of fats in the blood also decreases. A chronically elevated sugar level and an excess of free fatty acids in the blood leads in the long run to the occurrence of vascular diseases and diabetes.

Training increases our energy consumption only insignificantly

Scientists from Finland wanted to know how much more energy we consume on days when we do sports. Even intensive training increases calorie consumption by only about 10% on average. An interesting side result of this study: Those who do a lot of sport seem to compensate for this even unconsciously by sitting even more [7].

A study [8] from Texas also investigated whether intensive training has an effect on the metabolism of a high-calorie meal in people who sit a lot. One hour of intensive training made no significant difference to the increase in blood lipid values when the test subjects otherwise sat all day. Those who sat just as much, but managed an additional 17,000 steps, came off with significantly better values.

Movement is a basic right and necessity

Until now, health recommendations have concentrated on a certain number of minutes of sport per week. Although sport undoubtedly has many health-promoting effects and should therefore never be neglected, such recommendations no longer reflect the latest scientific findings. In view of the significant health risks associated with a sedentary lifestyle, we need a political and social consensus to limit the amount of time spent sitting to less than 4 hours per day if possible.

This can only be implemented if there is also the possibility of putting it into practice in everyday life. Offices must be redesigned in such a way that the human need for movement is recognized as a fundamental prerequisite for maintaining health. 


About the Author 

Eric Soehngen, M.D., Ph.D. is a German physician and specialist in Internal Medicine. With his company Walkolution, he battles the negative health effects that sitting has on the human body. 

Walkolution develops ergonomically optimized treadmill desks, which help to bring more movement into the daily work routine in the office or home office.

Photo credit: Jozsef Hocza

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