I think it is due to poor project planning but every few months I find myself needing to go back into sprint mode – a time when I have to stop all extra-curricular activities, get on a good, regular sleep schedule, and spend most of my time in front of the computer working. This is different than an Agile sprint because work becomes all-consuming.
The key to sprint mode is seeing an end in sight. If you can’t see the end then you start to lose hope and that’s the worst thing to happen in that situation. It’s also nice if you can schedule some down time after being in sprint mode but I’ve never found time for that.