Well,
gman and rhale:, I don't know how old you are, but I'm assuming you haven't hit 50 yet. I always hope I'm still around when all you whippersnappers who think you are immortal and omnipotent start getting referred to your hearing doctors, your hernia surgeons, and getting mail from Medicare Supplemental Insurance companies

I won't tell you how old I am, but let's just say if I had had a way to go overseas when I was a baby, I could have thrown my pablum bowl at Hitler and Mussolini. And it's like Indiana Jones said to his girlfriend after he got dragged under the truck and she commented that he wasn't the man he used to be. Indiana said: "It's the mileage, sweetheart--the mileage."
So yes to the bad back, yes to the hernia surgeries, yes to the injured shoulder, yes to arthritic joints, yes to benching about half of what I did when I was 35, and yes to having beat the crap out of two bouncers in one night when there ended up there were three of them--that sort of thing will send you looking for alternative solutions in a hurry.
Russ