Seconded.
Found that lack of fluids (water!!!) was the source of many of my headaches, so I came at this solution from that angle.
As an aside, this does require you to chunk your work differently. I've found it's a great practice to use such opportunities to keep up with the communication part of your work, so that when you hit the desk again, your mind & messaging apps are clear of those social notifications
My tip: drink a LOT of fluids. You will have to keep going to the bathroom which is a natural break point, and not something as abrupt as an alarm; the urge to pee sort of creeps on you, so you can stay in the zone until you really gotta go. The hydration is good for your brain/body anyway, so win-win.