For bed-sized quilts, I figure on a side a day, and that takes me about an hour to do. I watch TV while doing it. I use straw needles and do wear a thimble because if I don't they cut into my fingers. Slow and steady wins the race!

When I hand stitch the binding, I'll put a goal into finishing 1 side at a time while watching TV. If my hands don't hurt by the time I get to the next side I'll continue but sewing for 1.5hrs a night is about my max. And yes, I use tiny stitches too plus a thumble at times.

Finer needles and thimbles like everyone else has said. But you also should look into hand stretches to keep keep your ligaments loose and prevent cramping. I hand quilt as well, and the routine is sew for about an hour, stretch out my fingers and take a 5-10 minute break, then start sewing again. Also taking some kind of anti-inflammatory before you start is helpful.

I am very slow at binding, too, and just do a little at a time. What I find essential is a rubber finger to help me grip the needle.

I think the key is to start out with a shorter time, then do it regularly and build up the time. This is what I needed to do when learning to play guitar and clarinet. If I played too much when I hadn't played for a while, my fingers would get so sore from the guitar strings. After a while of regular play, the tips would callous up. For the clarinet, it took me a while to strengthen up my lip muscles and breathing muscles again. I also agree that metal thimbles are hard to use, I do have one that is leather and works for me better but I still mostly bind by machine as I really think that is stronger as well as faster.

Agree with ginger, those leather pads are the only thing I use, and a ladder stitch. It does take me about 4 or 5 hours to finish

I finally finished binding my quilt, it's about 75 x 90 I think. Made the hanging sleeve to go with it from the same material as the backing, but won't put it on until I decide if I want to enter it in the show or not....give my fingers a rest.
The problem wasn't with muscle cramps in my hands, it was pokeing the needle through the binding fabric...it was a piece from my stash and even though I washed it first it was stiffer than what I expected it to be. Changed needles and used more of a downward over my thumb stitch and that seemed to help. God forbid that I ever have to remove the binding for anything., it's on to stay!

First of all, have you tried non-thimble thimbles that stick on your finger, such as ThimblePads or UltraThimbles? I really like the small metal disc thimbles.

If you decide you STILL can't use a thimble, then you'll have to learn to not use your finger to push the needle through. Instead, grasp the needle between your thumb and forefinger and squeeze to push/pull the needle through the fabric. Hopefully this action won't make the muscles in your hands sore, or exacerbate any arthritis you may have. Personally I find it's easier to use the stick-on thimbles.