At least since Red Bull's introduction to the U.S. market in 1997, energy drinks have become common in many diets around the world. In fact, one study in Europe revealed that as many as 30% of adults over 18 consume energy drinks regularly ("'Energy' Drinks Report," 2013).

Energy drinks can owe their success in part to the ways in which they are marketed, like as a way to combat tiredness at work. Advertisements for one product, 5-Hour Energy, have even claimed it can combat the "2:30 feeling," a euphemistic reference to the natural lull in circadian rhythms that often occurs to many people in the mid to late afternoon. But being tired at work is a common affliction; readers may not be surprised to learn that, at least in one survey, over 90% of respondents said they had tried one or more methods to increase their energy levels while at work, and that caffeine is a necessity for their workdays ("More Than Sixty Percent," 2015).

Although a dose of caffeine can temporarily improve cognitive performance and elevate mood in a tired person, energy drinks often have very large doses. Where a cup of coffee has about 80 milligrams of caffeine, and a dose of 200 milligrams can be enough to cause caffeine intoxication (characterized by anxiety, insomnia, upset stomach, twitching, and restlessness), some energy drinks have boasted caffeine contents as high as 500 milligrams (Toblin et al., 2012). The Mayo Clinic considers 400 milligrams to be a safe limit for adults over the course of an entire day (Howard, 2017). Besides the caffeine content, energy drinks contain other stimulants as well as large quantities of sugar or sweeteners. Little yet is known about exactly how caffeine interacts with these other stimulants, like guarana, taurine, and L-carnitine, and studies that support the claims that energy drinks (as opposed to caffeine alone) boost physical and cognitive performance are limited (Alsunni, 2015).

What is known about energy drinks is that consuming them increases heart rate and arterial blood pressure because of the high caffeine dose (Alsunni, 2015). Excessive and regular consumption has been shown to disrupt sleep, causing drowsiness during the day (Toblin et al., 2012), exacerbating the fatigue a person means to combat by drinking energy drinks in the first place. A study of U.S. service members on a combat deployment to Afghanistan in 2010 revealed that nearly half of the surveyed service members consumed at least one energy drink in a day; almost 14% drank three or more (Toblin, et al., 2012). Considering that caffeine enhances diuresis, the regular or excessive consumption of energy drinks in an arid climate like Afghanistan's would significantly increase risk of dehydration, compounding fatigue and affecting alertness, performance, and general health. In addition, the service members who consumed three or more energy drinks per day also reported obtaining an average of four fewer hours' sleep per night compared to those who drank zero to two per day (Toblin, et al., 2012).

Like service members, many industry shift workers likely consume energy drinks to combat drowsiness or non-alertness while on the job. Some may claim that coffee is not enough; the caffeine in a cup or two of coffee doesn't get them to a productive state of wakefulness, so they use energy drinks. But what could be happening instead is that the energy drink habit—continual intoxicating doses of caffeine and stimulants—has disrupted their bodies' ability to get recuperative sleep, so they become reliant on the habit as a poor substitute for rest.

From a workplace health and safety perspective, monitoring employees' intake of energy drinks could positively affect behavior-based safety lapses, given the correlation between excessive consumption of energy drinks and sleep disruption leading to fatigue. Other solutions like more intelligent shift scheduling and fatigue management systems, like Predictive Safety's PRISM and AlertMeter platforms, can help employees avoid relying on energy drinks to be productive and alert. Other countermeasures to combat fatigue in the workplace, like snacks, hydrating drinks, short breaks or rest, and reasonable doses of caffeine like a cup of tea or coffee, and so on, may help energy drink consumers to temper their habit more healthily and at the same time improve safety at work in a subtle but important and effective way.

Alsunni, A.A. (2015). Energy drink consumption: Beneficial and adverse health effects. International Journal of Health Sciences 9(4): 468–474. Retrieved from

"Energy" drinks report. (2013, Mar. 6). European Food Safety Authority. Retrieved from

Howard, J. (2017, Apr. 26). What that energy drink can do to your body. CNN. Retrieved from

More than sixty percent of U.S. workers admit to workplace mistakes due to tiredness. (2015, Jan. 13). PR Newswire. Retrieved from

Toblin, R.L., Clarke-Walper, K., Kok, B.C., Sipos, M.L., & Thomas, J.L, (2012). Energy drink consumption and its association with sleep problems among U.S. service members on a combat deployment—Afghanistan, 2010. Morbidity and Mortality Weekly Report (MMWR) 61(44): 895–898. Retrieved from