In the last couple of years, there has been a lot of talk about sitting being as unhealthy for us as smoking. What is all the fuss about?
I think that one of the first things that needs to be considered is how much you sit during the day. Some people have desk jobs, and may be aware that they sit a lot. However, a lot of people feel that they are very active and are not sitting much. One thing that can be very enlightening is to add it all up. On a typical day, how much time do you spend sitting in your car? Sitting at your desk? Sitting to eat? Sitting using electronics, such as the computer, tablet, or watching TV? Sitting at work? Sitting at school? Sitting on a bike? (Yes, part of the problem with sitting is the angles of your joints, so even though a cyclist is moving, those times still need to be including in total sitting time in the day.) Are there any other times that you sit?
For most of us, answering these questions leads us to realize that a good portion of our day includes sitting. Therefore, if sitting is harmful, we should recognize why it is harmful and what we can do to fix it.
Sitting and the SAID Principle
Most athletes and coaches are familiar with the SAID Principle, which refers to the fact that the body makes Specific Adaptations to Imposed Demands. In other words, if you want to become stronger in a certain area, you train that area and your body responds. If you start a lot of new leg exercises, your muscles will increase in size and strength, the tendons will thicken, and you will increase the blood flow to the area.
However, our body will also adapt to more passive things. If we are sitting for many hours a day, certain muscles tend to stiffen and shorten, while others may become long and weak. Then, even when we stand, we are not moving optimally due to these adaptations that our muscles have made. For example, in order to be effective, runners need to have a significant amount of hip extension. If their hip flexors are stiff and tight from sitting, this will affect how well they are able to run. Short stretching sessions and a run will not be able to offset all of the demands of sitting. For example, even if you stretch for 30 minutes and run for 2 hours, you are not going to be able to offset 8 hours of sitting at your desk.
The most common sitting adaptations that I see in my practice are forward heads, rounded shoulders, tight pectoral muscles, rounded thoracic spine (the first step to the dreaded “dowager’s hump”), rounded lower back, short and tight hip flexors, hamstrings and calves. These common- almost ubiquitous- problems contribute to neck and back disc problems and arthritis, rotator cuff pain, hip pain, even knee arthritis and plantar fasciitis. This is a very abbreviated list, but it is certainly an example of how sitting can cause a lot of problems.
Sitting and Blood Vessel Geometry
One of the interesting things about sitting is that it causes certain blood vessels in the neck to become even more compressed due to the forward head posture. This same thing is seen in the hips. This causes more turbulent blood flow in these areas, which leads to plaque build up. This is not something that disappears if you eat perfectly or work out a lot. The fix for this is simply avoiding these positions for prolonged periods of time.
Is Sitting Killing Us?
The reason that we are starting to hear more and more about the problems of sitting is that there are several studies in the last 5-6 years that are starting to show that sitting more than 6 hours a day is associated with higher risk of early death, and greater incidence of chronic diseases, including cancer.(If you are interested in looking at some of these articles in more depth you can go here, here, and here.) At this time, no one knows for sure all of the different factors that are leading to this problem, but it is clear that we need to find ways to sit less and move more. I recommend starting now, by getting up from your computer and walking around the room.
Monica Clinesmith, DPT, is a staff physical therapist at Great Moves. She graduated in 2005 from the University of Iowa. She is Level 2 certified in dry needling, and is also certified in the Functional Movement Screen.