I'm 34, but I thought I'd share my experiences anyway.
I tried lifting every other day on the cycle I'm finishing up, but it was to much for me. I found that the seventh day of the week, complete rest, did wonders for me.
Still, in the post 5s, working out 3x per week is tough. You need to manage fatigue well, and skip some work if you need to.
For example, I do bicep curls and skull crushers on "off" days, but I skip them all together if I feel the need to reccover a little more.
As another example, I accidentally skipped bent over rows in my last workout. Not sure how, I just skipped it! But I did pull ups, so my lats were worked. Honestly, I'm glad I did, because I was beat the next day!
Anyway, I think reducing the work(especially here in the post 5s) is a reasonable thing to do, if recovery is an issue.
Frequency is an important principle, though. You are taking advantage of the anabolic state your body is in. I'd hazard a guess that reducing the number of exercises and maintaining frequency is more beneficial than reducing frequency on a higher number of exercises.
Did that make any sense? It makes sense in my head -- not sure if it comes out right in writing.