If you’ve just finished a hard work out or any kind of cardiovascular workout that has that your heart rate up a great breathing technique that helps get your heart rate down safely and effectively is breathing slowly in through your nose holding for a split second and then slowly Exhaling out of your mouth.
A lot of people tend not to be able to control their breathing and breathe in through their mouth and out through their mouth which can cause too much air in, make you sound like your hyperventilating, cause dizziness, and not to mention a dry mouth.
When you breathe in through your nose there’s more control in the air supply that goes in and when you exhale out of your mouth you want to purse your lips together to slowly push out the air.
Go ahead and give it a try! This technique can be found in yoga, meditating and simply for relaxation purposes.