“Sitting for long periods of time — when you don’t stand up, don’t move at all — tends to cause changes physiologically within your muscles. You stop breaking up fat in your blood stream, you start getting accumulations of fat … in your liver, your heart and your brain. You get sleepy. You gain weight. You basically are much less healthy than if you’re moving.”—If you’re reading this Tumblr post while sitting down, stand up! Here’s more reasons why.