One way (but strickly depending on your physical state (strong heart, good lungs, blood circulation splendid to normal), which from what you write is very good) is:
Holding your breath .. but holding your breath .. h o l d i n g your breath.
To succeed: Take three slow, deep breaths (in-out is one), and then h o l d i n g your breath.
This way you must succeed, after the normal foreplay, thus taking into consideration that normally our lady partner needs more time than we, men to get into the mood for that soft, sweet inner explosion.
Take care,
Faith
--behold the turtle! it makes progress o n l y when its neck is out--