The importance of proper planning, rest and recovery can't be overstated.
I foolishly "forgot" that I would be helping out with the simple moving job . . . and trained my legs on Friday.
Come Saturday morning at 11:30 am (and only half of the truck loading completed), I was wishing I had fresh legs.
Two take home points:
Take your daily activities into account when you plan your workouts. You don't want to train so hard that you negatively effect the performance of "other" activities.
Muscles targeted in a workout should be given at least 48 hours rest and recovery before being retrained.*
It'd sure be nice if I ALWAYS practiced what I preached -- my legs aren't going to be happy for the next few days. OUCH!!
* Longer rest may be required, dependent on the size of the muscles trained and the intensity of the training session.