Sighing is something we do whenever we are bored, and to which we give little to no importance. But, actually, the act of sighing is more important than you may think.
Actually, and in spite of normally being an act done unconsciently, sighing has been recognized for having a positive impact on our mind and body, because it is a simple but effective way to release innter tensions and to normalize your breathing rate.
Besides doing it in times when you are not at your best shape, you should also sigh whenever you feel the need to.
And, to experience relaxation using, you sho sighing as an exercise for that effect, you should not matter about the sounds you may emit whilst air leaves your lungs towards the exterior.
We can compare sighing to opening a soda bottle: when you decide to energically shake the bottle and immediately remove the bottle cap, the tension inside the bottle will be released, and after that, the inside of the bottle will be in a state of normality.
And like as in opening a soda bottle, sighing as a conscientious act is a method of relief from negative thoughts "trapped" inside ourselves, a method to achieve relaxation.
By the way, have you ever questioned yourself on why you sigh whenever you fell tired or sad?
Well, surely that you do not do that just so that others can realise you are not on top of your game! Whilst this may be a consequence of sighing, the real cause of sighing lyes in the need of relief from the silent suffering that originates from tensions and bad feelings that we keep to ourselves.
Consequently, when tensions build one over the other, when we tend not to express these feelings with other people or to find alternative ways to "lose steam", we will be bound to reach saturation point some time soon, with the consequence being the release of these feelings suddenly and in violent fashion.
Sighing is a great counter to what may be at sometimes a psychiatric study case, by being a great anti-stress method, which is free of charge too!
As for breathing, we do it as an automatic act, and most of the times we don't take the time to access our breathing rate.
Note that by simply realizing this, you are instantly executing a relaxation exercise, thus being a relief from inner tensions as well, and maintaining your health - both physically and mentally.
The key to relaxation through breathing exercises is simply to breathe deeply.