We used to laugh at the pompous US-made movies at North Luffenham showing their approved straining maneouvres - we just got on with it without any need for jockstrappery or centrifuges.
... But experience is really the key to G-tolerance and that means plenty of high G practice, particularly during flying training!
I mean its not like a good AGSM will reduce fatigue or provide an increased level of protection in a sustained turn.... Or that an experienced operator with a sh*t AGSM can't GLOC...