coffee is a drog. if you drink a lot it will lose its effect.
What is good about coffee:
introduction:
look what coffee makes to you:
I don't know to explain with scientific terms but i will explain how i understood.
imagine you have an energy bar. - like that healthbar/manabar/fatiguebar in videogames
when you have 100 energy you are full - like in the morning when you get up
in the course of the day you lose energy.
now every organism comes to play. Some people need to go to sleep when their energy level drops to 30, others go to sleep when it drops to 20, others to 40... etc
let's say your organism needs sleep when your energy reaches 30.
what does coffee do?
a lot of people imagine that coffee raises your energy. But it's not what it does. In fact it lowers your bottom line - the line where your organism needs sleep.
So if you need to sleep when your energy is 30, if you drink a cup of coffee, you will need to sleep when your energy drops to 25 - this way you imagine you win 5more energy points.
what you do with that extra energy is up to you 
this is why you can't really drink coffee instead of sleep
this^ is the usefull part of coffee.
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the bad part:
coffee is a drog. so when you drink a lot ... in time it will not have the same effect.
for example:
first time a person drinks a cup of coffee, it lowers his level by 5poins. If that person drinks coffee for a period of time, he will lose that 5points bonus... A coffee will give him only 4 or less points - I hope you understand...
and because it's a drog you can beccome addicted to it. psychically and physically.
psychically when you want that cup of coffee because you want it 
physically when you start shaking if you dont drink coffee for a period of time. - a friend told me how he was addicted to cocacola. he told me that he was literally shaking when he missed a drink one day. - same with coffee i guess
but it's not really bad. It's not like an addiction that you can't get over it or something if you want. It's something easy to deal... i guess
I just wanted to tell you(and others) that if you drink a lot of coffee it will lose/lower its benefical effects
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another bad thing is what it makes to your hearth. I don't know if it raises your bloodpressure but i know it gives you ... i don't know the english term for "palpitatii" - that's when your heart beats faster and unreagulary
^^ these apply if you drink like a maniac. If you drink with moderation i think it's ok.
here's a link about coffee. From what i see, it's pro coffee but it uses a lot the term "moderation"
I worked in a hospitall and all the doctors were saying that coffee is bad to health. A general recomandation for all the people with hearth problems is to drink less coffee
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Me and coffee
because you asked if we drink reagularly:
I use coffee only when i need it realy realy much for it's benefical things - for example if i have an exam tomorow and i have to learn all night... fuck school!
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coffee and poker:
i used to drink coffee to keep miself wake at the tables untill i found on a forum a post of a SNE player who said that he doesn't drink coffee at all. If he feels sleepy he goes to sleep for 1-2hours.
I think it's better this way than to alter your health just to stay awake and alert at the tables.
If you drink coffee for this^ reason, you should reevaluate the situation. As I said over time it will lower it's effect and you will need more coffee to keep you awake.
More coffee = more side effects. It will probably not kill you but your hearth will get tired over time making your overall finess going down.
If you drink coffee just for the fun of drinking than you should reconsider the situation because you win nothing and you lose a lot in the longrun. try tea or just water.
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You know... when we were born we didn't need coffee. Why do we need it now?? Do we really need coffee?
I'm not against coffee because it has some benefits but i don't drink it to much because i don't want to lose its effect:)
I drink it only when i really need it.
I preffer to sleep 1h instead of drinking a cup of coffee. If i can't sleep and i really need to be alert, i drink a cup of coffee.
I hope you read this even if it's a long post.
Sorry for my english
cheers and good luck ♦