Sutra 2.43 says, SELF-DISCIPLINE in practice leads to the destruction of impurities and to the perfection of the body and senses.
Hm. Lofty goals.
The 3rd NIYAMA (practices for self-care) is TAPAS. Tapas can be translated in many ways -- regularity of practice, heat, fire, discipline, continued effort, transformation -- but the message is pretty much universal. The MORE you come to your mat with regularity, the more you will create positive change, leading to the likelihood that you'll keep coming to the mat. FUN!
In tapas practices, we build heat or INNER FIRE which is said to burn off impurities. These impurities may be due to what we eat, how we act, how much screen time we take in and/or environmental factors. And when we experience the transformational potential of our practice, it creates a positive neural groove to encourage us to come back again and again.