One very important part of yoga practice is pratyahara.
At the beginning of our asana practice, pratyahara shows up when we actively decide to settle down. We choose to soften our gaze or close our eyes. And we rest our bodies in stillness for a brief time. It is also when we actively restrain the senses and focus the mind in guided relaxation practices at the end of each yoga class. It takes skill to step back and disengage from the forward momentum of life long enough to deeply relax.
In yoga tradition, there is a nice metaphor to describe how attachment to sensation can derail us. The body is a chariot carrying the self/soul as a passenger pulled by horses (the senses), and driven by our intelligence, using the sensory mind as reins. The sense objects are the path on which the horses pull the chariot. If the horses are poorly trained or the chariot driver is inattentive or unskilled, the chariot careens off course. In other words, without a disciplined mind and right understanding, we suffer from the distractions of our uncontrolled senses, just as a charioteer suffers from trying to control untrained horses.
We make a decision to restrain ourselves from looking around, from trying to make sense of what we hear, from tasting, smelling, and from moving about. We surrender our bodies to gravity, and “let go” as we relax our need to coordinate or control our experience.
Relaxation is a tonic for your whole being and can liberate vast amounts of energy locked in the body by tension. Many people spend much of their lives in a state of physical and mental tension. The release of tension induces a gentle euphoria which suffuses the entire body and helps harmonise and integrate all aspects of our being.
Of course, it is not only to practice on a yoga mat . You may want to take a more practical approach toward sensory discipline and consider adopting a few simple lifestyle changes to tone down your habitual response to overstimulation. These include going to bed on time and being mindful in thought, speech, and action, to occasionally refraining from food, speech and entertainment; scheduling time to relax and go for a walk in nature without the phone, etc.
This training of the senses creates habits that support a balanced and healthy life, but most importantly from the yogic point of view - without actively practicing pratyahara by turning inward, one may struggle to establish and maintain a regular contemplation (dharana) and meditation practice (dhyana).