I am a huge fan of controlled breathing exercises, and most clients I see would and do benefit from a set of simple but effective breathing exercises. These are easy to incorporate even during the most hectic of days - these can be done upwards from a minute, anywhere - and best of all, they are free and will always travel with you.
While there are lots of different types of exercises available, the simple '4 counts in, 6 counts out' works wonders and is easy to remember. The more you do it, the better the results, as the body learns to relax as soon as you start. Controlled, smooth breathing patterns calm the nervous system and help us to re-focus, regulating blood pressure and oxygenating the blood (when stressed, we are often fall into a shallow breathing pattern). Sure, the first few times the exercises may feel odd, but just like any new skill, one gets the hang of them soon.
How often would it be beneficial to practice controlled breathing and for how long? Doing a few short sessions several times a day would be ideal. Do note that the idea is not to hyperventilate; quite the opposite, the controlled breathing exercises aim to develop smoothness and regularity of pattern, rather than 'deep' breathing. The are great for improving mental focus, and quieting down a head full of chatter.
Here's a recent article in the New York Times about the effectiveness of these exercises. To access the article click HERE