I always have a cup of coffee in the morning, and later drink regular water throughout the day. I saw a video of Ricardo Mayorga training for his fight against Fernando Vargas and before his workout he would have a very small cup of what I would imagine is pretty potent coffee. So I think as long as its not in excess and you don't use it to substitute sufficient rest for the energy you need, drink up.
I second that. Before training I used to drink a cup of coffee with glucose(instead of sugar). For the 1st 45mins of training Id be flying by once the second half of the session came around or if I'd done a hard few rounds on the pads I'd start feeling dizzy and my vision would go blurry. So now I only drink Coffee after meals( it makes me **** like a mutha****a) and then IsoTonic drinks before training:bbb
It is fine. In the acute it may raise blood pressure but in moderation there should not be long term trouble. It acts as an appetite suppressant but can cause a paradoxical effect in some people and make them crave sweets. Do not put anything in your coffee.