Hook breathing?

[scoles]

Could someone explain what this is. I read somewhere that the great Herbert does it so there must be some reason for it. Is it safe? Is it just another name for packing?

 

[SEDATE]

constant body temp is 36 C , just simple our body try to keep it 35.9C-36.1 C , the body only have an abilty to control very accurate and very sensitive control temp mechanizm by billons sensor on our body when goes 35C hypeothermia occur when goes below 32 C you die, rgrds

 

[naiad]

A thread which explains about hook breathing...
http://forums.deeperblue.net/freediving-training-techniques/29204-what-hook-breath.html