An energy drink may provide a temporary fix, but it does not address you body's basic needs such as good nutrition, exercise, and sleep. It can also be extremely hazardous to use energy drinks as a pre-exercise "pick-me-up."
Recently, drinks such as Red Bull, Monster, Rock Star, Amp, NOS, 5-Hour Energy, and many others have been marketed to the public as a sort of coffee alternative. These drinks are usually included amongst the health supplement region of a store, which in the case of energy drinks means nothing about their health value. Most drinks claim to give you a boost of energy with a "secret blend" of ingredients with energy-boosting properties. Since most of us are immersed in our cultures, we don't realize how we scurry rapidly about and exude a "push, push, push" mentality. Many citizens of other nations pick this up immediately upon a visit to the United States, however. It is the desire to get things done quickly and without having to worry about energy loss that makes us incessant coffee drinkers. For some, the potent taste and questionable flavor pushed them away from the coffee craze. Now, however, energy drinks fill the gap for many who cannot stomach coffee. They usually provide a large dose of sugar (sugar-free brands excepted), caffeine (often disguised as guarana), taurine, ginseng, and a myriad of other mood-altering or mood-elevating substances.
The first time I witnessed noticeable effects of an energy drink was when I observed my college roommate return from a military team tryout. The tryout consisted of aggressive physical activity, including footmarching with a heavy pack for a number of miles, running a certain distance, and doing a number of body weight exercises like pushups, situps, pullups, and lunges, and team-building exercises such as carrying a heavy log and filled sandbags a certain distance. To motivate himself to complete the exercises, my roommate took two 5-Hour Energy drinks. He made it to part of the way through the footmarching when his body simply quit wanting to move. When I came into the dorm room, I found that he was so tired that he fell asleep with his head in between his knees before he could lay down. All efforts by me to wake him were in vain for at least 30 minutes, which was extremely disconcerting.
Obviously, my roommate's circumstances were out of the ordinary. Certainly a singular event does not constitute proof in any scientific sense of the word. What does constitute proof is numerous scientific studies of caffeine and heavy exercise which support my initial conclusion that caffeine does bad things to an athlete who is exercising heavily. This is because caffeine is a diuretic, which means that it causes the body to lose water. Water is vital for exercise, and the lack of it during periods of strenuous activity can lead to decreased physical performance, heatstroke, fainting, and in extreme cases, death. Basic training soldiers are forced to drink many times a day, because their leaders have been trained to realize that every body needs water. The body is composed of approximately three-quarters water, and the body's cells need that water to operate correctly. A lack of it changes the chemical balance within the body and degrades its performance.
Caffeine and other energy-boosting supplements also raise your heart rate. It may seem logical that you want that to occur in order to be faster and push harder. In fact, the body injects hormones into your bloodstream such as adrenaline to do just that. If it didn't boost your heart and respiration rate, then your muscles, organs, and brain would not receive the blood they needed to operate, and you would pass out. Pre-loading your body with caffeine, then, prematurely raises your heart rate above normal, and causes your body to operate at an even faster tempo. If your heart over speeds, then it can lead to serious health problems. The answer is simple: exercise and energy drinks do not mix.
What about normal everyday life? Caffeine has been around and imbibed for centuries, so why are we complaining about it now? One issue is the quantity of the caffeine contained within energy drinks. In 5-Hour Energy, for example, there is 138mg of caffeine in two ounces! This is 30mg more than eight ounces of coffee. For a complete list, see http://www.energyfiend.com/the-caffeine-database To be fair, 5-Hour Energy is not the worst offender. In fact, it's not even close. One mad potion called Fixx Extreme packs 400mg into a .17 oz. package! Serving portions this extreme will undoubtedly cause extreme stress upon the heart. Remember that caffeine is a drug, like alcohol and nicotine, and addiction can occur. This makes the drug ineffective, which naturally leads to the downward spiral of increase dosages and tolerance.
There are a number of completely intuitive activities that are more than effective in energizing the body, including eating, sleeping, and exercising. If you are not successfully accomplishing any of these three tasks, doctors recommend that you cease trying to create false energy and attempt to use real energy. Food gives you calories, and sugars, fats, and proteins are broken down by your body over time to provide a stable source of energy. Sleeping replenishes the body's systems after a day's abuse. Exercising causes an increase in circulation, which increases the flow of oxygenated blood to the body's systems. Caffeine and sugar rushes merely imitate these processes and cause your body to forget what it really needs. They also make sleeping difficult! If you feel like you need the boost, be prepared to pay the price. You are facing an eventual crash, increased susceptibility for sickness, and greatly increased stress on your cardiovascular system.