Energy Drinks Lead to Insomnia, Nervousness in Athletes

Energy drinks, while they may be tasty and give you that extra kick, have been shown to cause increased insomnia and nervousness among athletes, according to new research.

With the energy drink craze having spiked in recent years, now more than 50 percent of athletes guzzle this liquid boost during training and even before competitions. And although they have been shown to improve sport performance between three and seven percent, there are also negative effects on top of the positive ones.

A team of researchers at Camilo José Cela University (UCJC) had top footballers, climbers, swimmers and basketball, rugby, volleyball, tennis and hockey players drink the equivalent of three cans of energy drink or an energy drink placebo before a sports competition.

Using GPS devices the researchers determined an athlete's distance and speed during their performance, and dynamometers and potentiometers were also used to measure muscle performance.

"Athletes felt they had more strength, power and resistance with the energy drink than with the placebo drink," Juan Del Coso Garrigós, one of the study' authors, said in a statement. "However, the energy drinks increased the frequency of insomnia, nervousness and the level of stimulation in the hours following the competition."

There was found to be no difference between male and female athletes.

Energy drinks mainly contain carbohydrates, caffeine, taurine and B vitamins, with little difference in the quantities and ingredients amongst the main energy drink brands. And despite what their name clearly suggests, the main driver of their appeal, energy drinks do not provide more energy than other soft drinks, researchers say. They merely have an "energizing" effect provided by the caffeine.

In fact, none of the other ingredients actually produces a significant effect on physical or cognitive performance.

Although for competitive athletes, these "insignificant" pros may outweigh the cons.

"Energy drinks increase jump height for basketball players, muscle force and power for climbers and trained individuals, swimming speed for sprinter swimmers, hit force and accuracy for volleyball players and the number of points scored in tennis," Del Coso added.

The findings were published in the British Journal of Nutrition.