At what point in studying should I give up for the night?

It is important to keep a glass of water beside you while studying, as this helps your brain work. Keep sipping so your brain has this fluid to function. When it comes to a stage where you're taking more bathroom breaks without making any progress, when your eyes are heavy and it seems you've exhausted every opportunity to make further headway with your work, then your brain has switched off and it's safe to say your comfy bed is calling!

I would say when you reach a point that you don't feel like you're making progress and would benefit both emotionally and physically from a little sleep or rest.

Probably as soon as you feel too tired to focus properly. Trying to learn while that tired is almost a waste of time for many people. Rest well and continue another day when you are properly focused and able to store the information properly.

Never try to force yourself to do too much. As soon as you feel tired or are starting to overthink, that is definitely the time to get some sleep. You may feel that the next day, once you have had time to rest, studying becomes slightly easier. Set up a plan for studying which allows times for breaks and also make sure you are not overdoing it.

Listen to your body and mind. When you feel sleepy and unable to concentrate then it's better to get a good night sleep and then again continue the next day!

It's a tough balance, especially if you need to cram. Pace yourself throughout the term so you will not find yourself needing to cram quite so much. After you hit a point of the night where you are more tired than awake, chances are you are not cognitively benefitting much from the studying anyway so it is best to rest. For this reason, I also found it helpful as a student to do "boring" homework (like reading a textbook), at the gym on the treadmill and used post-its/flags to mark important points for review later. Exercise stimulates the brain and seemed to very much help commit information to memory. The flags allowed for a quicker review and way to take notes later on when I was able to be still enough to write. Also remember that you do not have to be perfect. It is better to show up well-rested, bright, and alert for your exam to get a good score AND be health than to worry about destroying your health for a perfect score.

When you can't concentrate anymore, when you reach that point when you aren't going to retain anything.

I have found that studying is something that needs to be balanced with rest. The most important consideration is whether continued study passed certain time cuts into the amount of respite for your mind and body to recover. This means frequent breaks and at least 8-9 hours sleep. A good rule, to begin with, is 45 min of work to 15 min breaks and ensuring that you get to bed to allow for a good rest. Personally, I find any study after 9 pm pointless as my brain and body are too fatigued and only cause severe stress for the next day.

When you begin to feel tired or you cannot retain any information, you should certainly close the books for the night! Choosing to rest and not study does not mean you are giving up either :) Your health is important so you should always make sure to take breaks while studying and don't over-do it! Set goals for yourself during your week so that you can spread out your study habits and not be forced to crunch in one night!

You should give up studying when you don't understand what you are studying. It helps to meditate for ten minutes and going to bed. That way you will be able to concentrate when you start studying the next day preferably in the early morning.