if you have a plan, and stick to it, you wont be in the gym any longer or less than normal.
I have a 5 day workout plan where I hit each body part twice pretty much, one for power/strength, the other time for hypertrophy. I do this on cycle or off.
I just lift heavier/harder on cycle. but either way, im in the gym 1 1/2-2hrs.
but if you go in and wing it (on cycle), you'll find yourself in the gym for 2-3hrs before you realize it, and prob still wont be tired, but you'll be hungry, which is when you'll look at the clock after your 8th set of incline bench.