I work at a desk all day and I have no tme to excercise. I was wondering if there is excercises I can do while at my desk.

get a small set of hand weights, even stress balls are fun ... the whole standing without using your arms for leverage is good ... make it a point to take the long route to your desk/office if you have the time ... instead of tooling around the internet, take a good pace around the office instead ...