I never go to the range when tired or not 100% to minimize the chance of making a careless error. I just got back from a business trip and planned to go to the range since it won't be as busy on a weekday, but being tired from travel I opted to stay home.
This made me wonder though if I should practice occasionally when I'm not 100%. If I'm home asleep and someone breaks in, I'll be sleepy or slightly disoriented. I could have the flu. In either case, if I had to defend myself, am I ready?
I would expect building good routines and muscle memory when I can focus on it should make me more capable when I'm notable to focus as well. Any thoughts? Does anyone practice when not 100%?