conditioning for powerlifters. Why no improvement?

[NotThatUgly]

I've been training for years and whenever I make a serious effort to improve my conditioning, I never seem to notice any improvement. I can see the progress of my lifts, or my body size/shape, but when it comes to cardiovascular conditioning, there's been no noticeable improvement ever.

I remember I used to cycle to work up a hill every day. The first time it killed me. The 100th time.... it still killed me. I see the same thing today. I made an effort to do some HIIT, with goblet squats. There's been no progress. Every time I want to puke after the 4th or 5th interval. Even when deadlifting or squatting for reps (anything above 5 or 6) I sometimes just get that awful crash feeling of having zero energy and wanting to vomit.
I went through a phase of hitting a heavy bag. I would try to do rounds, 20 minutes total 3 minutes on 1 off. After a few months, instead of my total time going up, I was still barely holding on for the full 20.

The problem is not food. I'm overfed, I'm close to 20%bf so I'm no starving myself.

Does this happen to anyone else? Is there something wrong with me?

[Jason2459]

Yup

[SA249]

Id suggest starting with something that doesn't make you want to puke, and progress over a longer period of time.

Sled drags, light single arm carries, incline walks on the treadmill might be a bit friendlier.

Think of what you are doing as being similar to if you tried to hit a heavy single on deadlifts every day, and ended up hitting a wall. Build a base before you attack it.

[Jason2459]

Blood work never hurts