I was taught some breathing exercises that calm the mind and slow the heart rate. They all have different arm movements but the idea is the same. For "Praising the Sun" you stand with your feet together and clasp hands in front of your waist. Then while raising your hands out in front of you inhale as much air as you can until your hands are directly above your head with the palms facing up. Hold your breath as long as you can and then drop your hands about six inches and let the air settle to the bottom of your lungs. Lower your hands, outstretched, to your sides until they reach your hips. Then push your hands out to the front, at hip level, while you exhale. Then take a full inhale while spreading your arms and exhale at your normal breathing rate while bringing your arms back to the previous position. I have found this exercise to help when I want to calm nerves, get in a state of "no mind", or need to recover from hyperventilating.