Our bodies are meant for standing, not sitting, according to Loma Linda University Health. Sitting too long, particularly in a cramped position, can potentially pinch some of the nerves in your body, particularly the sciatic nerve in your lower back. Without much movement for a few days, the muscles in your body begin to weaken due to the restriction. Being in a cramped position for too long can also cause digestive problems such as bloating and cramping because your abdomen is compressed, according to the Vein Center of Florida.
If you’re on a long flight, you’re often told to get up and move around every few hours. That’s because sitting in a cramped position puts you at risk for blood clots, according to Live Science. These blood clots can form in your legs and move up to your lungs. If this happens and treatment isn’t available, your body can go through cardiac arrest or some lung tissue could die (via Penn Medicine).