Or...breathing in a specific pattern! That may involve a certain number of inhales and exhales, or holding an inhale or exhale, or even breathing in one nostril and breathing out another nostril.
According to Hindu practices, prana is the energetic life force that exists in all of us. Yama means to gain control of. So Pranayama is the practice of gaining control over the prana (or energetic life force) inside our bodies, using breath. Certain pranayama practices can increase your energy or calm you down (among other things). Just like when your mom told angry 6 year old you to take 10 deep breaths to calm down when you were angry.
When you go to yoga class, or have a session with a yoga therapist they will often include pranayama in the practice. Yoga therapists can tailor the breath practice to help with various conditions such as anxiety, depression, or fatigue.
Are you interested in learning how pranayama can help you? Let me know! Fill in the contact request form or email me at firstname.lastname@example.org.