To optimize the brain's natural wake-rest cycle, taking a break every 90–120 minutes may be a good idea. However, this is individual, and if you feel you're getting distracted or tired, you may want to take a break sooner.To optimize the brain's natural wake-rest cycle, taking a break every 90–120 minutes may be a good idea. However, this is individual, and if you feel you're getting distracted or tired, you may want to take a break sooner.