It just depends on the actual workout itself. If it's arm day, I should get done with that in 30 minutes because I'm not going to be sitting around taking long rest periods. Whereas with legs or back I might take a little bit longer with the heavier lifts. I'm trying to make sure that in the workouts where I'm going extremely heavy—like if I know I'm going to be doing a slightly higher-rep set of squats with 300 or 400 pounds—I'm going to make sure I have enough rest time between sets that I can actually get those weights for those reps. But if the weight isn't that heavy, I don't really need the extra rest.
And especially when I'm doing 7's, I'm maybe going to rest two to three minutes at the most [earlier in the workout], and then once I hit those 7's at the end, I'm resting only 30-40 seconds. I believe you need to take enough rest to lift heavy weights, but if it takes you 5-10 minutes to rest and get psyched up for a big lift, I don't know if that's going to be good. Because now you're not going to be in a bodybuilding zone; you're going into more of a strongman or powerlifting mode, where it's just about strength and you're not getting any cardio or the same pump. So anywhere from one to three minutes' rest is usually good for me.
Yeah, I'm pretty instinctive. Let's say I'm doing front squats and something just isn't feeling right with my technique, then maybe I'll go to a machine instead or just switch to back squats. It's usually based around machine work. If I'm doing a certain leg press and I don't like the way it feels, then instead of scratching leg press off completely, why not change it to vertical leg press? Most gyms have more than one type of equipment. So you find out what works best for you, and that may change from day to day. But that's where you have to be willing to adapt.
