I work out every day in the morning for an hour and then follow up the lifting workout with abdominal training for 10 to 15 minutes. I usually do one body part a day and the hour-long workout will consist of about six to eight exercises, with four sets per exercise. My rest time between sets depends on my goal of the set. If I am trying to build size, I will take up to two minutes rest between sets, but if I am looking to do a lifting cardio session to build the endurance of the muscle and burn fat, I will keep my rest time between sets under a minute.
Anyone that is in the gym for over an hour is either talking too much and wasting time or trying to take on too much in one session. Everyone’s current state of conditioning is different, but even the most conditioned athletes have a limited about of muscle glycogen (energy) available at a given time. Much like your cell phone, the charge only has so much life and after a lot of use, it’s time to plug your cell into the charger. When lifting, you are much like a cell phone battery and in my mind, after an hour it’s time to recharge it and get out of the gym. If you stay in the gym longer than an hour with max intensity, I feel most are hitting the point of no return and causing more adverse effects than positive effects.