How long is the optimal (healthy) time where you can perform research work productively and be focused without taking breaks? This is assumed to consist mainly of mental work (writing, developing ideas, reviewing other work, etc.) but may include active work in the lab as well.
I can usually do 2-3 hours at a time (up to 5 if I am really focused and well-rested) - I am curious if this is a typical amount of time experienced by others. I know people who can work 10+ hours without even a bathroom or food break but others who cannot work for more than a half hour at a time.
When you do take breaks, what sort of break activity is the best to recharge your mind, in your experience? Eating/drinking? Social activities? Spending time in nature? Resting in a dark room? Changing to a different project for a while? Praying or reading?