Research published in Diabetologia found that those who sat for the longest periods of time were twice as likely to have diabetes or heart disease, compared to those who sat the least.6 Sitting for more than eight hours a day has also been associated with a 90 percent increased risk of type 2 diabetes.
Colon Cancer: Excess sitting may increase your risk of colon, breast, and endometrial cancers. The mechanism isn’t known for certain, but it could be due to excess insulin production, which encourages cell growth, or the fact that regular movement boosts antioxidants in your body that may eliminate potentially cancer-causing free radicals.
Findings presented at the 2015 Inaugural Active Working Summit also found that sitting increases
Lung cancer by 54 percent
Uterine cancer by 66 percent
Colon cancer by 30 percent
Another reason for this increased cancer risk is thought to be linked to weight gain and associated biochemical changes, such as alterations in hormones, metabolic dysfunction, leptin dysfunction, and inflammation—all of which promote cancer.
Digestion: Sitting down after you’ve eaten causes your abdominal contents to compress, slowing down digestion. Sluggish digestion, in turn, can lead to cramping, bloating, heartburn, and constipation, as well as dysbiosis in your gastrointestinal tract, a condition caused by microbial imbalances in your body.
According to Microbial Ecology in Health and Disease,
“There is growing evidence that dysbiosis of the gut microbiota is associated with the pathogenesis of both intestinal and extra-intestinal disorders. Intestinal disorders include inflammatory bowel disease, irritable bowel syndrome (IBS), and celiac disease, while extra-intestinal disorders include allergy, asthma, metabolic syndrome, cardiovascular disease, and obesity.”
Standing requires you to tense your abdominal muscles, which go unused when you sit, ultimately leading to weak abdominals.Hip Problems: Your hips also suffer from prolonged sitting, becoming tight and limited in range of motion because they are rarely extended. In the elderly, decreased hip mobility is a leading cause of falls.Sitting also does nothing for your glutes, which may become weakened, affecting your stability and the power of your stride when walking and jumping.
Varicose Veins. Sitting leads to poor circulation in your legs, which can cause swelling in your ankles, varicose veins, and blood clots known as deep vein thrombosis (DVT)
Weak Bones. Walking, running, and engaging in other weight-bearing activities lead to stronger, denser bones. Lack of activity may cause weak bones and even osteoporosis.