When I was involved in Theatre, as well as diaphram control, I learned Intercostal Breathing. This is the trick to act dead on stage without your chest moving. It REALLY expands your capacity when you learn to do it unconciously, but you don't need to do it conciously while singing. And coupled with "breathing from your stomach" as the martial artists say, really works the diaphram.

With full lungs, you should be able, with good breath control, and without strain, to hold a note until "normal" people (who aren't doing it right) fall on the floor exhausted. With proper training, you should be able to hold a note for an enormous amount of time - and you don't need to force much more volume of air out to sing with more volume - it's called "Projection".

Used to play these "dare games" as a kid when singing with the social youth choir...

You DO need to warm up to get this mode "switched on" unless you have learned to breathe like this all the time!

That's the argument with all these nice Pop "breathy singers" - they always use the mike, so don't need to "sing properly". I was watching some "Carols in some big place" thing the other night and one of the "rave" female "pop-stars" was having to grab 2 or 3 breaths EACH LINE to sing simple carols - she was barely lasting 3 words per breath - and you could see that she was labouring. The other one was just ghosting along - she was breathing so well that you could hardly detect it.

And you shouldn't get what Little Hawk mentions if you are doing it properly - if you are getting what he mentions, then you are still breathing at the top end only of your lungs.

Robin