What about routines for building muscular endurance? I lifted weights for the 2nd time in my life 8 months ago and I've been doing it 5-6 times a week ever since. So I don't have a lot of experience.
When I first started lifting I did something pretty close to a 5x5 and gained 25# of muscle (I was skinny as hell). But then I realized that my muscular endurance wasn't all that hot. I spent 4 weeks doing descending sets exclusively and saw huge endurance gains. For instance, for dumbbell presses I started with 70# dumbbells, went to failure. Immediately (no break), 65# dumbbells... etc. in 5# increments. Same pattern down to 20# DBs. Then, 15# dumbbells for 30 seconds as fast as possible, same with 10#, 5# and sometimes no weight at all.
I'd estimate that the entire "set" took between 7-8 minutes and consisted of around 150 repetitions. Then, I hit the treadmill for 5 min. and then do another descending set. Believe me, at first it's hell but you get used to it.
I thought I would lose strength, but last week I started doing 5x5 again and I'm a little stronger than I was when I stopped.
What do you think about this kind of routine? Positives? Negatives? I really appreciate your input. Working out is an experiment for me.