How do you keep yourself awake??

I couldn't study without fighting sleepiness.

I don't like coffee very much.
However,I drink it before studying midnight.
If I don't so,I'll come to feel sleepy at onece.
Then,I never use milk and suger.
I always drink coffee Black and Non-suger!
I drink it with thinking "this is medicine...!"

Do you come to feel sleepy when you study?
If you so,how do you keep yourself awake?
Please tell me good ways!!