That's alot. How often do you play for this long?

Stretch, exercise, diet... the obvious stuff will help. But gettin old ain't for sissies (my karate instructor said).

I am 45 years old.  We practice everyother Saturday if we don't have a gig.  We start at 12 noon and played the last time until 7 pm with 2 brakes.  We are up to about 60 songs now and still didn't get through all the material.  My hands are sore and usually my lower back. I take Aleve.  I have to play two church services the next day and getting started is tough.  I guess after about a song or two, I just forget about it and do what I have to do. I think moving equipment bothers me more than the drumming.
I have to say that mentally, I am more like Chip71.  I put the pain out my mind because the show must go on. When the lights come on it is show time.
                      Nutty

Try taking pain-killers BEFORE you play - that's a trick I learned from a buddy of mine who's in the military: take pain-killers (particularly anti-inflammatories like aspirin or aleve) BEFORE the strenous activity that's going to cause the pain. Also take some more when you go to bed after a gig - that might make the morning after a bit less of a drag. When I first started playing with Pat Travers, my hands hurt a lot, because I'd never played so hard in my life. I learned to always have aspirin or excedrin handy.

This is what I do also.  Before and after.  Im 45, and have been doing this for the last couple of years.  Its part of getting old(er) I guess-

The best idea is to probably put up witht the pain, basically having sore muscles is a sign of adaptation, meaning you will be able to withstand that kind of activity. Although drinking a glucose solution would also help, as it will help reduce muscle fatiguing and therefore any soreness.

You will also save loads on paracetemols

The key to playing along time and still keeping everything from hurting the next day is eating right, Taking the time to work out (you know like in a gym) and spending lots of time behind the Drum Set. Another good point is to work on not trying to play so hard, Sit back and just chill. I went to from playing 1/45min to playing 4/55min in 4hrs. After that first time playing 4/55min, the next day I was in bed about to die. Now I can play 4/55min for 3 or 4 times a weekend.

Pain killers? Isn't that a bad idea? I notice a lot if I drink a lot of booze before a show, I am not that good but even moreso I don't notice myself pulling stuff in my arms/legs and end up doing damage to my muscles that I wouldn't have done. Almost all pain killers are bad for you, I hear. I just personally think blocking out pain is a really bad idea, you should really know if your body is in pain, it means something is wrong.