The breath-holding thing is all about the CO2 build-up in your bloodstream, and it's about a tolerance level to it. So, if you relax, efficiently keep your oxygen, and not make this CO2 build-up more extreme, you can actually hold [your breath] more efficiently.

David Blaine once held his breath for 20 minutes and 2 seconds, during which his heart rate dropped to 8 beats per minute.

Sleep deprivation is one of the most amazing ways—if it's controlled—to go to another place [hallucinate].