You guys are right about me being too old to lift heavy anymore. I should have figured that out on my own the last... 3 times I tweaked my back doing dead lifts, or the second time I strained my lat doing heavy rows (that one still hurts). I can't even describe how bad my arthritic neck aches after heavy squats.
The thing is I still have a lot of... motivation to get stronger. I don't think I've really learned my lesson yet. I really pushed hard to get a 520 squat on my 52nd birthday, for example. Missed it by 45lbs, but I did unrack that sucker just to get a feel for it. I can say I'm going to back off, but I know when I get to the gym I'm not going to think about the risk of injury as much as the "need" to lift more.
I can at least skip the max lifts.
@rutman is right. It does nothing for building muscle. Maybe I can set a minimum rep count to, say, four. Something like that : )