Warm-up, stretching, and workout length


I have read that in order to maximize GH response and testosterone levels, and minimize cortisol levels, training should be kept at about an hour. My question is this: Does this hour include the mandatory warmup and stretching periods? That doesn’t leave a whole lot of time for iron-hoisting? How long do most people here lift for. I would lift for three hours straight if that would help, so I know I can take plenty of time to warm-up and stretch. Any help is greatly appreciated!