For many people, working at a desk all day might seem like the perfect cop out for your expanding waistline. But in reality, there are plenty of ways to work out while you're at work. Working at a desk from 9 to 5 - or even longer -- definitely decreases your mobility. And yes, it also increases your chance for weight gain. Muscles grow stiff and tight after long periods of sitting in one place. But there are ways to get around having your day at a time at a standstill. Stretching regularly prevents muscles from stiffening and promotes the flow of blood. There are a bunch of exercises that will help you loosen up. Sit up straight in your chair, stretch your arms over your head for 10 seconds and then alternate reaching higher on the left and then the right. Or tilt your head to the right so that your ear almost touches the shoulder. Press the head lower and hold for 10 seconds. Relax and repeat on the other side. Here are some ways to get a quick exercise fix without ever leaving your desk. Stand up and sit down... without using your hands. Repeat over and over.