Most articles discussing the dangers of excess coffee focus primarily on coffee’s caffeine content.
The only side effect I’ve ever suffered is dehydration, which was caused by drinking too much coffee (caffeine dehydrates) and not enough water. I felt mentally wired and physically lethargic at the same time.
Adequate water intake offsets/prevents this problem.
As for how much is too much…
Specific amounts – I think – is largely dependent on your own personal use and tolerance levels.
Here’s a link to an article that details caffeine’s side effects:
http://www.naturalnews.com/012352.htmlThe article is very one sided, slamming caffeine without mentioning any benefits of it or its sources like coffee, tea, chocolate, etc.
But it does highlight caffeine’s negative effects on uncontrolled neuron firing which leads to the pituitary gland secreting
"unnecessary" ACTH and adrenaline hormones.
Again, the degree of these sides is largely due to the amount of your consumption, which is also dependent on your tolerance levels.
The article also seems to assume that everyone is inactive – spending their day between sitting at a desk and on a sofa – which supports their claim that the hormonal releases are unwanted, unneeded, and not at all beneficial.
Those who use caffeine pre-workout understand the faults in this argument.
To get the other half of the caffeine debate, read this post that details caffeine’s positive effect on resistance training performance and enhanced glycogen replenishment:
http://www.getbig.com/boards/index.php?topic=230226.msg3244843#msg3244843
