Q: do you have any office exercises that target office malaise?
A: Sure, there many office exercises you can do throughout your workday. For some you don't even have to get up from your desk. They will help break up your work day a bit and give you an energy boost.
If you have the room, get up and do body-weight squat exercise -- one of the best all-around exercises. Of course, if you are wearing high heels or other footwear that's not exercise-friendly you'll want to take the shoes off before doing this exercise. And if your clothes restrict your range of motion you may have to only do a half-squat instead of a full one. 10-20 repetitions of these should get your blood flowing again!
Even if you are unable to get up to do any office exercises, you still have a few choices. One simple exercise is knee extension. Sit up straight in your office chair with both feet on the floor, then extend one leg out so it's parallel to the floor, hold it for a second or two, then return it back down. Then repeat the same exercise with the other leg. Continue alternating legs until you've done 10-20 repetitions with each.