Research on pranayama has shown the following benefits..
Decreasing in anxiety and depression
Decrease in blood pressure
Increased energy levels
Reduction of stress and overwhelm
With deep and regulated breathing, you can reverse these symptoms instantly and create a sense of calm in your mind and body. When you breathe deeply and slowly, you activate the parasympathetic nervous system, which reverses the stress response in your body. Deep breathing stimulates the main nerve in the parasympathetic nervous system—the vagus nerve—slowing down your heart rate, lowering your blood pressure, and calming your body and mind.
One of my favorite breathing technique:
Alternate Nostril Breathing:
When you are feeling anxious or ungrounded, practice Alternate Nostril Breathing, known as Nadi Shodhana in the yogic tradition. This will immediately help you feel calmer.
Hold your right thumb over your right nostril and inhale deeply through your left nostril.
At the peak of your inhalation, close off your left nostril with your fourth finger, lift your right thumb, and then exhale smoothly through your right nostril.
After a full exhalation, inhale through the right nostril, closing it off with your right thumb at the peak of your inhalation, lift your fourth finger and exhale smoothly through your left nostril.
Continue with this practice for 3 to 5 minutes, alternating your breathing through each nostril. Your breathing should be effortless, with your mind gently observing the inflow and outflow of breath.