Sitting for long periods can lead to weakening and wasting away of the large leg and gluteal muscles. These large muscles are important for walking and for stabilising you. If these muscles are weak you are more likely to injure yourself from falls, and from strains when you do exercise.
It can be due to reduced blood flow, tight muscles and ligaments, fluid pooled in the body's lower extremities, or pins and needles sensations in the feet.
Leg pain can have many causes, but your description of aching after prolonged standing or sitting suggests a possible buildup of fluid in the leg veins (chronic venous disease, venous insufficiency).
But when experts analyze the handfuls of studies examining the effects of prolonged sitting, the data shows that sitting for more than eight hours a day can have a serious impact on a person's health.
Sitting can also lead to overall deconditioning, early muscle fatigue, weakened core stabilizers, and tightening of the hip flexors, resulting in increased stress on your low back and reduced spine flexibility.
Leg weakness can be caused by a variety of medical conditions, some of which are serious. Possible causes include stroke, systemic diseases, inflammatory conditions, nerve damage, muscle disorders, and medication side effects.
Sitting for prolonged periods of time can be a major cause of back pain, cause increased stress of the back, neck, arms and legs and can add a tremendous amount of pressure to the back muscles and spinal discs.
Research has linked sitting for long periods of time with a number of health concerns. They include obesity and a cluster of conditions — increased blood pressure, high blood sugar, excess body fat around the waist and unhealthy cholesterol levels — that make up metabolic syndrome.
The strategy that worked best was five minutes of walking for every 30 minutes of sitting. This strategy also had a dramatic effect on how the volunteers' bodies responded to large meals, producing a 58% reduction in blood pressure spikes compared with sitting all day.
The average American sits 8 hours a day. That is quite a stretch of time when our bodies could benefit from movement, physical activity or even standing. This sedentary period of time, researchers have found, can increase our risk of obesity, metabolic syndrome, heart disease, cancer and even death.
Leg fatigue or heaviness can be caused by various conditions. They include: Varicose veins: The leg veins become enlarged. Peripheral arterial disease (PAD): Buildup of fat deposits in the artery walls, thus, causing inadequate circulation of blood in the legs.
The sensation of heavy legs, also known as venous insufficiency, is related to poor circulation. It occurs when blood flow from the legs to the heart is impaired, causing the heaviness.
Muscle weakness is commonly due to lack of exercise, ageing, muscle injury or pregnancy. It can also occur with long-term conditions such as diabetes or heart disease. There are many other possible causes, which include stroke, multiple sclerosis, depression, fibromyalgia and chronic fatigue syndrome (ME).
Often, the cause of weakness or pain in the legs when walking is a narrowing of the space around nerves that carry signals to the lower part of the body. When symptoms affect your legs, the condition is typically lumbar spinal stenosis.
Problems with the joints, (such as arthritis), bones (such as deformities), circulation (such as peripheral vascular disease), or even pain can make it difficult to walk properly. Diseases or injuries to the nerves, muscles, brain, spinal cord, or inner ear can affect normal walking.
Sitting doesn't just affect the bones and muscles. It affects metabolism as well, and as we gain weight, it's more pressure and increased force that go through the joints and can cause more injury. You also see decreased blood flow. People end up with more varicose veins.
Scientists analyzing data found that it takes about 60 to 75 minutes of "moderate intensity" exercise to undo the damage of sitting for at least eight hours a day.
But consider this: A growing body of evidence suggests that spending too many hours sitting is hazardous to your health. Habitual inactivity raises risks for obesity, diabetes, cardiovascular disease, deep-vein thrombosis, and metabolic syndrome.
It is thought excessive sitting slows the metabolism – which affects our ability to regulate blood sugar and blood pressure, and metabolise fat – and may cause weaker muscles and bones. Research on astronauts in the early 1970s found life in zero gravity was linked with accelerated bone and muscle loss and ageing.
The natural curvature of the spine supports the weight of our body evenly. The longer one sits, the more strenuous it becomes for the body. If you suffer with nerve pain, sitting for long periods of time is slowly damaging the nerves over time.
Poor posture is both a cause and sign of muscle imbalance. Continuously sitting, maintaining an incorrect posture when you stand or sit, or letting your shoulders droop for a long time could leave a few muscles unworked, making them weak.
Beyond ergonomic seating and 90-degree angles
Sitting for long periods of time creates a perfect storm of strain that includes joint misalignment and muscle weakness," explains Scott A. Rushton, MD, an orthopaedic surgeon at Lankenau Medical Center, part of Main Line Health.
"There have been some studies that measured the amount of pressure on the discs," says Dr. Atlas. "Not surprisingly, the pressure is lowest when you're lying down." But there is more pressure on the discs when you're sitting than when you're standing.