You hold at
your end range of motion, pushing against your own body tissues resistance, but gently, and slowly breathing. So for 12 breaths,
you are very still.
Stillness drives energy into the body and stretch relieves stagnation - poor circulation, energy and nerve flow. Very healing! It's as close as you can get to reversing the aging process of your body.
By pushing toward your breaking point (but not past!) and enduring the discomfort for longer and greater intensity, you build massive stress resilience! (You never have to endure more than mild discomfort! Just stop at "mild" and hold - you will naturally build resilience and go further in your daily training.)
Result: you can take more stress, calmly, but know your limits and refuse to hurt yourself. You focus your mind on what you want (effectively now!), so you're happier and more fulfilled in your life. Your body moves, feels, and looks better!