Sparring day is one of those things that people usually have a love and hate relationship with. At the gym I go to it is safe to say that we are all novices, so we have a lot of areas where we can improve on. Since this is a contact sport and concussions are a reality it is important to recognize sparring should be practiced responsibly.
There are gyms out there that spar hard every practice after a session. From my own experience I can confidently say that sparring too often is counter productive. Save sparring for once or twice a week. You have to give not only your body but also your mind time to heal.
When I have a heavy sparring day I do not like to jump into another day of crazy sparring the very next day. I find it most beneficial to sit on your thoughts of the sparring session and think about what you learned. Reflect back on what you experienced and learned from the spar, give yourself time to digest it. It is just like learning any other scholarly material, you can get burned out on it. If you cram you will just get wrecked.