When we practice asanas in yoga we stretch and influence all the meridians (energy channels) in our body. We also influence our nervous system. This can bring about big changes in the body.
After a yoga practice you need to give the body and your nervous system time to assimilate these changes. If you skip the integration part (Savasana) after a yoga practice and go straight back to being active the chances are you will feel agitated and on edge. This is unnecessary and if you keep doing it that way, your nervous system will become chronically over-stimulated.
A general guideline is to take 6 minutes in Savasana for every hour you practice.
I believe everybody should build in enough time for Savasana after a yoga practice.
I even believe it is the most important (and maybe the hardest) pose to master. But it’s so worth it!