kickboxing.....does anyone do it?

I was a tournament fighter long ago.
I studied Shotokan.
If your serious about self defence: Krav Maga or similar.
If your interest is fitness PX90 or the like to start and get in shape and Yoga for your mind.
You must eat/drink properly to maximise and maintain your results.

Endurance is the key to health and wellbeing.