Having taught yoga to children starting at age 5, I have found that one can't start young enough with practicing yoga. There is so much stimulation going on in a child's life with (digital) games, sweets, how they should behave to be accepted, pressure from school and home to "do well at school". Without them being aware of it, this creates a lot of tension.
When doing yoga with kids it’s all about discovering and accepting yourself.
We emphasize on how you feel in a pose, rather than how a pose should look like. Where most physical activities are more competitive, in yoga we focus on having fun and learning about how our bodies are all different and as there is no one exactly build alike no one is better or worse.
What we do have in common is that we all carry a beautiful light inside and when we are happy with who we are our light starts shining even brighter.
This is not something you can actually see but you can feel it. This is why even with the little ones we include meditation or visualization, to find a little bit of peace and stillness.
And the amazing thing is that most kids (even the really active ones) enjoy the relaxation part of yoga best!
Growing up knowing about your light and being able to find stillness is a tremendous gift and this is why I believe that one cannot start young enough with yoga!