I believe that the human body is not designed to sit for long periods of time. Many people come to me each year suffering from low back pain. S1-L5 Vertebraes seem to be the culprit for most of the discomfort. The most common problem is disc degeneration and herniated discs.
The human body is designed to be upright with all the muscles working synergistically to support the spine. If you go back in history you will notice that low back and postural disorders were not as prevalent. This is due to the fact that most people worked the land. They were working on farms and were always using their body and standing up. It wasn't until the technological age that problems started to develop among the masses. People had to leave the farm and start working in offices. Sitting at a desk for 8 hours is disastrous to the posture and health of the body.
Sitting at a chair in a 90 degree hip flexed position is not what the human body is designed to do for sustained periods of time. Driving in a car, sitting at a desk, watching television etc. for long periods will deteriorate the function of the back and the supporting muscles. The gluteus maximus is designed to work all day and to help support the hip and back. When you sit on your butt all day, this causes the glutes to turn off resulting in lack of blood and oxygen flow. The quadriceps and hamstrings shorten and also have poor circulation. The erector spinae muscles have to work harder in trying to support the torso. Since the glutes and hamstrings are not firing the erector spinae act as the primary stabilizers. Unfortunately, the erector spinae are not strong enough to support the torso for long periods of time. They are long and slender in composition and only provide a supporting roll.
Over time the muscles will fatigue and the discs will become vulnerable to damage. Sitting goes against the normal spinal curve position. The more you sit the worse it gets.
Another problem with sitting all day is that you increase your risk of heart disease. This is because sitting blocks the flow of blood of the main arteries of the heart. The big femoral artery delivers most of the blood supply to the lower body. When we are sitting for long periods blood circulation is slowed down. This can weaken the walls of the arteries. Also, blood pools in the lower abdominal region which makes the heart work harder in trying to pump the blood throughout the body. Over time this poor circulation will begin to weaken the integrity of the arteries and blood clotting factors (arteriolsclerosis) can develop. Once the artery is occuled then a myocardial infarction (heart attack) can occur. It doesn't matter how good of shape you are in. If you are sitting behind a desk all day you increase the risk of having an heart attack is greater than those that stand up all day.
Sitting all day also reduces the body's energy output. The resting metabolic rate is slow. Meaning that caloric output is at a minimum. Standing up and moving around will activate more muscle in the legs and therefore will increase the resting metabolic rate. More calories are burned.
If you are sitting all day I suggest the following.
1. Stand up every fifteen minutes and walk around for a few minutes.
2. Perform 5 repetition of squats. Hold hands straight out from body and squat down.
3. Stretch the quadriceps
4. Return to sitting. Do this every 15 minutes for every hour you sit.
5. Drink plenty of water throughout the day.
6. Avoid smoking.
tags: back care, sitting, daryl conant, vince gironda, ron kosloff, nutrition, strength and conditioning, building muscle