I took a nice long bike ride a few days ago. I was sick of staring at a computer screen, and I thought maybe activity would help me focus.
It did, but I needed a day's rest first. Which almost defeated the purpose.
In all seriousness, these sorts of deadlines do get me going -- it's just there's an optimal amount of stress we need that really helps us write productive, relatively bug-free code.
I feel like I should and could have done more for a chunk of time between (looks at repo commit dates) May 16 and June 21, but my testers gave lots of good feedback that let me implement some low-risk, high-reward stuff.