I started adding a little HIIT because I wanted better conditioning but I honestly didn't expect it to affect my regular gym sessions much. After a few weeks I noticed I wasn't getting as winded between hard sets and I felt like I could get through higher volume workouts without feeling completely drained.
I also like that the sessions don't have to be very long. Has anyone else noticed HIIT carrying over into their lifting or general fitness?
I think consistency matters more than making every interval brutal. Once I stopped trying to destroy myself every session I could actually stick with it and recover properly.
The main benefit I've noticed is that my conditioning doesn't interfere with my lifting as much I used to get out of breath before the muscles I was training were actually tired.
I noticed the same thing. My rest periods started feeling much easier especially after leg training. I wasn't suddenly stronger but I definitely felt like I could recover between sets better.
For me the biggest change was work capacity I used to feel finished after a few hard sets whereas now I can get through a full session without my conditioning becoming the limiting factor.

I started doing HIIT mainly for fitness and ended up enjoying the mental side too. Short hard intervals are uncomfortable but getting through them made longer workouts feel much less intimidating.
better conditioning makes repeated efforts feel less exhausting
