You have probably never seen repulse Monkey done this way before as a simple Qigong exercise. The Kidney is very important in traditional Medicine as it powers the whole energy system of your body.
To be specific the exercise stimulates the Belt Meridian which circles your waist. The Belt meridian is unusual in that most of the energy pathways go either u and down the limbs or body.
Take it nice and slow by not trying to breathe too deeply or doing too many reps. five breaths is more than enough to start with each day, especially if you are doing the exercises i have shown you before in this blog.