When is it time to take a break?

I wanted to edit this:

The title can mean a few different things.

What I am referring to is lets say you are playing non stop a few hours a day or more and working on stuff that is very difficult for you to play.

Once your fingers start hurting should you ease off? Or just keep going?

What would be best to keep them strong and increase strength?

Also, if you ever get into a rut where you just cannot come up with anything good or cannot get any better should you take a break all together?

The more you practice the better you get but should there be valid breaking points?

Fingers should never hurt so you probably just need to stretch or warm up a bit before you get to work. When I get in a creative rut, I just pick a song that I want to learn and go at it. It's a more relaxed fun thing to do and I always learn something cool about song writing or riffs, technique, etc.

I used to play 3 hours a day for 6 days a week. My fingers never hurt but I'd have callouses. Just like in sports (e.g. weight lifting) if it hurts, don't use it for a while til it's not hurting anymore....