Mate - Coke ?

Zaneblue, I´ve got a question for you:

Do you think Coca Cola (light) will affect PE due to caffeine ?
I am also into Mate. Here in Patagonia Mate is the equivalent to green tea. To me mate is one of the ways of drinking a lot of water.

I am now facing a new PE routine (will stick to it for 4 months at least) and the only part of my diet that I am not sure of is Coke and Mate.