For me, this is related to the anxiety and excitement that betting causes; mixing coffee, energy drinks, or other drugs will only intensify the effect of these sensations. Personally, I have a set schedule for my activities; I rarely spend more than two hours betting. Using the example given for a sports bet, I simply place the bet and wait for the result; following the game won't make it go my way. Of course, I enjoy watching the matches and bet more on the local championship; I don't have to force myself to stay up late at night, for example.
Taking coffee and energy drink is not the best option and just like you said it won't still change what the result will be, but as a human being and the money involve is a money that can change life for instance, you will be so eager and curious to see what will be the final result and to some point your mind won't be at ease until the game is over and even when the game will be over if it doesn't go well ( in your favor) your mind won't still be at ease because you will be calculating what you would have used the money for and how rich you would have become.