Freediving and Kidney Stones

Aloha Binsted,

You should have your friend look up the physiology of "Shallow Water Black-out". There are acidity changes involved in partial pressure variations during the more extreme breath-hold diving. I forget the details, but freediving may actually be helpful. But, you have to do some research and there is a lot of research out there on this subject. For example, when you push yourself too hard on a dive and when you come up to the surface you feel the urge to urinate. This is your body trying to balance out the acidity levels created by the excessive CO2 that has built up. There are a couple other physiology factors that might also be helpful. He should look into it.

Hope this helps!

Aloha