Many people now spend long hours sitting at work, in front of computers, in cars or looking at their phones. For some, sitting throughout the day has become such a normal part of daily life that they may not realize the potential health consequences.
However, research shows that prolonged sitting, especially when combined with insufficient physical activity, can affect several functions of the body, including muscle activity, heart health and the way the body processes sugar and fat.
Studies have found that sitting for six to eight hours a day is associated with a higher risk of cardiovascular disease. Sitting for more than 10.6 hours a day has been associated with a 40% to 60% higher risk of heart failure.
The World Health Organization (WHO) says standing up for three to five minutes every 30 minutes can reduce the rise in blood sugar and blood fats that commonly occurs after eating by about 60%. Standing for six minutes every hour can also help improve the body’s metabolic function and lower blood pressure.
1. The body uses less energy and its functions change
When a person sits for long periods, the body uses less energy than when standing or walking. The leg muscles and other muscles involved in movement are less active, causing the body to reduce the amount of energy it uses.
The Mayo Clinic says prolonged sitting is associated with health problems including obesity, high blood pressure, high blood sugar and changes in blood-fat levels.
2. Blood sugar may become harder to control
When a person remains seated for a long time, particularly after eating, the body may not regulate blood sugar as effectively as it does when the person walks or engages in light physical activity.
Research shows that standing, walking or doing light activities during periods of prolonged sitting can help reduce the rise in blood sugar and insulin levels that occurs after meals.
This is important because consistently poor blood sugar control can contribute to an increased risk of developing type 2 diabetes.
3. The heart and blood vessels may face greater risks
Spending long periods sitting and being physically inactive can affect cardiovascular health.
The WHO says prolonged periods of sedentary behaviour are associated with a higher risk of premature death, cardiovascular disease, some cancers and type 2 diabetes.
Research has also found that prolonged sitting can reduce the activity of lipoprotein lipase, an enzyme involved in processing fats in the bloodstream, by between 80% and 90%.
WHO research indicates that people who sit for more than eight hours a day without engaging in physical activity may face a risk of premature death comparable to that associated with smoking or obesity.
4. The back, neck and muscles can become painful
Sitting for many hours without moving, particularly with poor posture, can lead to pain in the back, neck and shoulders.
Poor sitting posture places prolonged strain on some muscles and joints while leaving others underused. Over time, this can cause fatigue, pain and difficulty straightening or moving the body comfortably.
Studies show that 53.5% of people who sit throughout the day experience neck pain, while 53.2% experience lower back pain and 51.6% report shoulder problems.
Sitting for long periods can also increase the pressure placed on the spine, potentially contributing to spinal problems or displacement of the vertebrae.
That is why it is important to maintain a posture that supports the back, change sitting positions regularly and take breaks to stand and walk.
5. The leg muscles become less active
Walking helps the muscles in the legs push blood back towards the heart. When a person sits for long periods, these muscles are less active, which can affect normal blood circulation.
For some people, particularly those with other risk factors, prolonged inactivity and lack of movement may contribute to an increased risk of blood clots, especially in the legs. This can become dangerous if a clot breaks away and travels to the lungs.
Sudden swelling in one leg, pain or warmth may be signs that require prompt medical attention. If these symptoms are accompanied by difficulty breathing or chest pain, emergency medical care is needed.
The problem is not simply sitting itself. The greater concern is spending many hours seated without getting up, doing so repeatedly, and combining prolonged sitting with insufficient physical activity.
