Starting with small work outs or "bursts" of activity does indeed help. At a minimum, it gets you into the "idea" of getting exercise. As you become used to doing small activities such as taking the stairs, it gets easier and easier to work it into your day.

The more often you do this, the better you will feel. I've found that when I exercise, even a little, I feel better, even if I haven't lost any weight. It gives me the motivation to keep moving and to try to reach for bigger goals.