I'm not a big fan of energy drinks. Heck, even just running under the Red Bull arch as I come out of the water at a triathlon annoys me just a bit. As a nutrition consultant, for the sake of my clients I have sometimes wished in the past that energy drinks did not exist. And here are the reasons why:

1) Danger of Caffeine Overdose and Addiction: The average energy drink contains nearly 4 times the amount of caffeine found in commercial soda beverages and several of the more popular brands contain the caffeine equivalent of 14 Cokes. A 6-ounce cup of coffee has 80-150 milligrams (mg) of caffeine, but the caffeine content of energy drinks ranges from 50-500+ mg, with one popular energy drink "shot" topping out at 570mg, which gives you the equivalent of about three and a half cups of coffee with a single sip!

Why should this concern you? Because caffeine forces your adrenal glands to secrete enormous amounts of adrenaline and "energy" hormones, even when those glands are depleted. The result is a growing tolerance to the effects of caffeine, and eventual burn-out and severe adrenal depletion. This is accompanied by a feeling of increasing tiredness and a need for higher and higher amounts of caffeine to achieve an energy boost. Attempts at quitting the addiction can result in withdrawal symptoms such as severe headaches and complete loss of mental focus and function.

In addition, by inhibiting the activity of the vitamin folate, B12 and B6, high levels of caffeine may interfere with your body's ability to regulate two significant cardiovascular disease risk factors: homocysteine and cholesterol. By causing blood vessel constriction and increased risk of blood clots, the caffeine content in some energy drinks can literally be deadly for someone with high stress levels or high blood pressure. Finally, high levels of caffeine consumption have been associated with increased risk of stroke and arthritis, insomnia, heart palpitations, tremors, sweating, nausea, diarrhea, chest pain, and neurological symptoms!

Finally, since caffeine is a potent ergogenic aid for sports performance, you're simply reducing the chance that your body is going to pay any attention whatsoever to that caffeine infused gel you plan on consuming during your next race.

2) Sugar and Artificial Sweeteners. One can of energy drink contains the equivalent of nearly 10 teaspoons of sugar! This amount of sugar causes your sensitive pancreas to create a literal flood of insulin in an attempt to manage all the extra glucose (sugar) that ends up in the bloodstream. Some of this sugar may be used by the muscles, but usually only if you are exercising quite frequently. The remainder of the sugar is converted into fat by the liver. In addition, the body releases both epinephrine and cortisol from your adrenal glands (as if they weren't already stressed enough from the caffeine!). The result is  quick swing in energy, followed by a subsequent crash, a severely compromised immune system, a surge of cell-damaging "free radicals", thickened blood and an eventual insensitivity to insulin, also know as type II diabetes.  And you just thought sugar was bad for your teeth!

With the high amount of sugars you are already forced to consume while training and racing, drinking even more sugar in a concentrated, liquid form is not ideal for your body, even if it does "bump up" your afternoon work productivity.

But what about artificial sweeteners? Don't they eliminate this problem? Unfortunately, research has shown that there is still a release of gastric hormones when you consume an artificial sweeteners. This gives your brain a confusing message: that food is present, but that the food has no "calories". Subsequently, you develop an appetite craving typically 30-60 minutes after consuming an artificially sweetened beverage.

In addition, these artificially sweetened chemicals (yes, chemicals!) such as aspartame (Nutrasweet), sucralose (Splenda), acesulfame potassium, and sugar alcohols have been linked to upset stomachs, mood swings, birth defects, cancer, diabetes, emotional disorders, epilepsy, seizures, a variety of neurological disorders and even obesity!

3) Acids. Finally, carbonic acid, citric acid and phosphoric acid in popular carbonated energy drinks can dissolve tooth enamel (causing tooth rot and yellow teeth), raise the risk of stomach damage and ulcers, cause bone breakdown, osteoporosis, and bone fractures, and upset the fragile "acid-alkaline" balance in the human body (which was just discussed in more detail in podcast episode #53 at http://www.bengreenfieldfitness.com )

And that is why I am not a fan of energy drinks.