Be quiet, calm, focused, attentive to the present, mindful.
Some forms of exercise and sports are best performed with a high (though managed) degree of mental agitation. Yoga is not one of them.
Yoga Sutras, Verse II.47 recommends that in performing asanas, your effort should be relaxed (saithilya) while you absorb into the infinite (ananta). This means focused, attentive relaxation, not a wandering mind. Be alert to the asana, devote attention in the present to the asana. Employ your muscles, cardiopulmonary, vascular, nervous systems in a calm yet efficient fashion -- panic/anxiety/stress and their associated biochemical changes do have their place, but as a reaction to danger, not as a methodology for performing a planned action. When appropriate in the asana, you can ramp up your breathing, exertion, etc., while still remaining in control and attentive. Mind remains quiet while active. Lose yourself in the asana and merge with the Universe.
Physiologically the quiet of the mind has beneficial effects as feedback from keeping the body focused -- endorphins, dopamine, seratonin in the brain -- calm chemicals as opposed to anxiety chemicals. You can carry this over to the other aspects of your life. There is a yoga saying: Don’t confine your yoga to the mat.
Here are some techniques that assist with quieting the mind during asanas:
1) warm up the body parts used in the asana
2) Before moving, visualize an asana in its entirety – especially the key elements – imagine yourself performing the asana -- limbs, bones, etc. -- be mindful of posture
3) Understand and focus on proper priorities for movement, position, alignment of body parts, i.e. be attentive to the relative importance of the activities of the asana, as related to your body and your goals -- what is right for you; recognize your body particulars and limits
4) Know and use the proper breathing pattern; integrate breath with the asana; use breath to strengthen performance, control tempo, and improve stability
5) As you perform the pose, be mindful of what your body is doing: muscles, bones, torso & limbs, breathing, blood circulation, nervous system; do not let your attention wander
6) Be attentive to the chakra area along the spine (sacrum, pelvis, abdomen, chest, neck, head) that most affects, and is affected by, the pose; feel energy moving through chakras, spine, body; don’t lock the joints tightly -- that inhibits energy flow
7) Flow gracefully into and out of the pose; feel the flow of your breath, delivering peace and calm to your mind and body. Absorb into the Infinite.
8) Intentionally attempt to cultivate sthira (steadiness and alertness) and sukha (lightness, comfort, and happiness)
Performing asanas calmly also has value in achieving yoga benefits & goals without injury.
