No pushing, no extreme stuff, be mindful of your capacity and you will feel different.
Connect with the ground and feel it strong and firm under your feet. Build up to 36 if you want to - don't rush there.
Try three cycles first, then nine and go from there. If you start then, like I often do - get distracted - write the numbers 1 - 36 somewhere and focus on each number as you go.
Count on your fingers if all else fails, and if you have 36 of them, I'd love to know.
The idea is that we are gently moving stale energy (and releasing that which no longer serves us) out of the body and bringing in the new and fresh. Any clearing you do helps you and all the people around you and regular practice helps you strengthen and brings benefits to your body.
The new fresh air we breathe in has the stronger life force energy in it - especially if we are outside. Inside the house, the energy has slowed and is recycling around, this is why it's important to open windows and doors.
More lively energy brings you better life force.
Breathwork is used all over the world to balance mind and body, and has been known to help focus and also with pain relief. (Think birthing for example.)
You are breathing out the ideas and thoughts you have, and bringing in the energy of universal consciousness. This energy is stronger and clearer near water and is also contained in water, this is why we get great ideas in the shower or the bath, why the air is fresher at the sea and near lakes and waterfalls, and why we have more of a flow when we are hydrated.
We are what we think, and also what we drink! Fresh is best.
Have a try with the breath exercise and let me know how you get on.