Remember to Forget
When I'm working on something and I'm really into it I can forget to take breaks. Before an hour is up I'm usually losing my focus and the time would be better spent taking my mind off of it all.
I think it's more productive to just drop it occasionally and come back at it from another angle and let my subconscious mind chew on what I just took in. So while you're adhering to the action plan's 50/50 rule don't forget to squeeze a few percentages in there for breaks and relaxation. Some rules can be bent, others can be broken. If you're a little more rigid in your thinking then consider relaxation an action. It's the action that refreshes your research and other actions.
Maybe you don't need to be reminded. But I do. Ultimately that's why I wrote this blog. I don't want to burn out and let all the hard work I've put into this go to waste. Taking breaks is not being lazy. It's being productive!