An article published by DAN Europe, I consider to be one of the most valuable pieces of research into an aspect of deep freedive physiology that I have come across in a long time. You can read more here: http://www.freedivers.net/blog/?p=898
For more questions, you're welcome to join the remote coaching program. You'll shortly will see why there's no genral answers for your questions, and each one must have an individual approach.
