Part of mindfulness is to be aware of yourself and your surroundings in the moment. Through meditation you relax, or quite your mind and feel, or listen to your body.
Meditation can be used as a biofeedback technique to help you become aware of your bodies stressors and train you to respond and reduce the negative affects of these stressors on your mind and body.
Breathing is one bodily function that can be controlled consciously and unconsciously. Most of us are aware of our breathing and notice its increase or decrease due to physical or emotional stimulation. The awareness of and calming of breathing is an early step in meditation.
The average heart rate is 70 beats per minute. Most of us are aware of our heart rates increase or decrease do to physical or emotional stimulation, but unlike lying still and quickly controlling our breath, sensing the heart beat takes more awareness of your body.
Becoming aware of your heart is a step in advancing your meditation practice. One example of awareness of a heartbeat and its affect on the mind is that of a woman’s post-partum depression and doctors discovering that playing music which includes a sound of a beating heart equivalent to that of a fetus can help alleviate the symptoms of this depression.