I don't see anything wrong with taking a week off if needed. The key is to keep lifting and if you need to take time off so that you don't burn out then take it! I've done it and i always come back charged up and ready to get after it again. When you're at if for a long time and it starts to be a grind and like you said your body starts to feel beat up, take a break! I don't see anything wrong with it especially when you're over 40. Shit I have an 11 year old daughter who's knee keeps blowing up from over training soccer. she's fucking 11! time off is a good thing sometimes!