The are couple things to consider in red bull and similar drinks:
-the central nervous system stimulants like caffeine which keeps you alert
-simple sugars, like table sugar (glucose+fructose), high fructose corn syrup, and so on
-taurine, vitamins and ect..
As everyone knows the bad guy in the room is simple sugars. In short they work this way: their main property is that they are quickly processed and absorbed into the blood and result in a spike in a glucose (blood sugar). So if the glucose is high then with the help of insulin it is transported to muscle and liver and it is stored there in the form of glycogen as energy reserves. (When your blood sugar is low, glycogen is reverted to glucose which is consumed by body for doing its stuff). If there is still too much of blood sugar (as it can be the case if you eat simple sugars as they are released too quick into the blood) and your glycogen reserves are full, then glucose is transformed into fats and that's there all thw bad magic happens.
By the way glucose by itself is extremely important as it is the main ready to use energy source of the body and the only source of energy for the brain.
When doing their thing endurance athletes do use energy drinks (not the red bull type) to get energy from glucose and to fulfill their glycogen levels and to avoid hitting the "wall" when they run out of it. Also these energy drinks are enriched with electrolytes which athletes loose due to sweating.
So if you are not at the end of your second hour of your marathon run you should have enough energy reserves and you don't need to take energy drinks to increase the levels of energy.
Caffeine by itself is ok (unless you overdose it
but that's a general rule ) and in essence because of it and other stimulants you could drink red bull. (Not with vodka
)
So the conclusions no.1 is that if you need a red bull, drink sugarfree, as the can of red bull has around 25 grams of sugar and 0 grams of fiber (which delays the release of simple sugars) and that is close to the all day dose in one small can.
So the conclusions no. 2 don't get excited about orange juice and similar things as they are also very bad and full of sugar. Read the nutrition information and search for the amount of sugars in the products.
So conclusion no. 3 to get your energy use low release carbs with low glycemic index like oats and so on (I know, not that tasty).. Banana as ttmonster said is a an option if you feel out of energy. It is somewhere in the middle between low GI and high GI. Naturally the more ripe the banana is, the sweeter it is and higher GI it has.
And the last thing as I will get blisters from typic I use the following home made energy drink before going to the gym: cold coffee for "mental energy", instant or steel cut oats and banana for "body energy", protein powder for my muscles, water as needed. Add all this to the blender and blend
