Mizue in charge of "nobinobi yoga" recommends "an easy way to calm you down at desk".
Place your fists lengthwise on your desk.
Place your forehead on two fists.
Close your eyes to listen to your your breath and stay for a while.
Only in a few minutes you will find yourself in calm.
You can do this wherever you are confortable.
One very important thing is you need to concentrate on your breath.
Piled emails to answer? Put it away.
Don't try to think something else hastily.
To tell the truth this is very difficult,
while you are staying there
you may feel like saying something what you are not allowed to say
(that's why you needed to calm yourself)
or you may fall asleep drooling.....
Relaxation and taking a good rest is very very hard.