Muscles grow during rest, but not during the training. Strength training is just an incentive, but not the only condition. You should sleep at least 7-8 hours a day. Note, I mean a deep sleep and not just the opportunity to take a nap. In some cases, it is necessary to sleep more than 8 hours for the effective recovery, especially if you have stressful and hard work.
A break between each set during the training should be calculated on the base of the nature of the exercises, 2-4 minutes for the exercises with maximum efforts and 60-90 seconds for the exercises at low speed performance. The easier the exercise is, the less time for a break between the sets you need. If you do not give your muscles enough rest, the lactic acid that accumulates in them can negate all your efforts in the following set.
“More” does not mean “better” when it refers to the duration of your training. If you can maintain tension during the entire training duration of 30-90 minutes, it gives you an advantage for the natural increase of the muscle mass growth hormone level. This facilitates the recovery period. However, too long trainings can reduce natural testosterone production, increase cortisol secretion and reduce recovery functions of the body, you will feel yourself weak and jaded.