You know that nice kind of sore you get from a good workout? It's evidence that you pushed yourself a little harder than normal. When you do recover, you feel like you're in a better, readier state than you were before.
You can get something similar from work. It sets in at the end of the day, whether it be 5PM, 8PM, or 11PM. It's when your brain is almost fried, and you can go only a little bit more, but you know you should stop. Things feel a little surreal at that point. Like you didn't even notice the time passing. You shift back into reality and sounds become clearer, the people around you feel like people instead of rocks, and you realize you're hungry.
But just like a good workout, you don't have to work out all day to do good work. You can have an amazing workout in thirty minutes if you know what to focus on. Which means you can have an amazing day of work if you manage to focus on the most important things and work on those things for two, three, four hours. Pat yourself on the back if you actually even get that much done in a day. We've all experienced more lackluster days, most days.
Don't go overboard. I remember, one time, my arms and legs were so tired I could hardly get out of bed (I was rowing a boat or something). It was a strange sensation not being able to move, so much that it was almost funny, but it was definitely too much. Aim for when you can walk and move and run around freely, but you have that slight tension inside that's telling you you can't lift heavy things or run too hard today. When you're back 100% the next day or the one after that, you're ready to do it better, faster, and stronger.
Don't pull all nighters. Nobody's going to give you a medal. If you work so hard that you sleep all day the next day, there wasn't much point in staying up now was there? Instead, keep up the momentum of showing up every day. Keep going until you have a little bit left. Enough to start fresh on a full tank. You'll go a bit further every time if you keep it up. It adds up faster than you think.