Energy Drinks Linked to Side Effects for Athletes: Study

New research suggests that while popular drinks like Rockstar, Monster and Red Bull may provide athletes with a performance boost, side effects of energy drinks may cause insomnia, nervousness and other problems.

In a study published last month in the British Journal of Nutrition, researchers found that while the popular, highly-caffeinated beverages may result in a 3% to 7% increase in performance, the boost does not come without psycho-physiological changes.

Researchers from the Camilo Jose Cela University in Spain conducted a four year study focusing on the energy drink side effects. Using double-blind, placebo controlled trial, researchers examined the performance of 90 top athletes who played football, basketball, rugby, volleyball, tennis, hockey and climbers and swimmers. All participants were low-caffeine-consuming athletes.

The athletes took an equivalent of three cans of energy drinks, 3 mg caffeine/kg body mass, or a placebo before competition.

Sixty minutes after ingestion, athletes completed a training session. The researchers then used GPS devices to determine the distance and speed at which was covered in team sports. They also used dynamometers and potentiometers to measure muscle performance in other sports.

Overall, athletes reported experiencing more strength, power and resistance. Muscle power improved by three and seven percent.

Researchers indicated the athletes ran further in team competitions, at higher intensities. Basketball players increased their jump height, climbers increased their muscle force and power, swimmers increased their swimming speed, volleyball players increased their hit force and accuracy and tennis players increased the number of points scored.

Despite the improved performance, athletes also reported a number of side effects, including difficulty sleeping, nervousness and activeness, or increased stimulation, in the hours following competition. Researchers saw no differences in outcomes between male and female athletes in the incidence of side effects.

Energy drinks, like Red Bull, contain carbohydrates, caffeine, taurine and B vitamins. Most other energy drinks contain similar ingredients. The concentration of caffeine present in the products provide 80 mg of caffeine per 250 ml can, yet some energy drinks are sold in 500 ml cans.

Researchers reported that drinking Monster or Rock Star seemed to have an “energizing effect” from the caffeine in the product. No other ingredient produces a significant effect on physical or cognitive performance.

Widespread Use

More than 50% of athletes take energy drinks during training and before competitions, researchers estimate. The statistic is a cause for concern for some health experts, considering the other studies which have revealed side effects from energy drink consumption.

Other studies suggest energy drinks may affect the way the heart beats, causing it to have more forceful heart contractions. A study published in December 2013 revealed adults who drink energy drinks have significantly increased heart contraction rates after drinking the beverages.

A study published last month concluded energy drinks like Monster, Red Bull and Rockstar, pose a serious threat of heart problems. The study found drinking energy drinks may be linked to an increased risk of angina, irregular heartbeats and sudden death.

More than half of the reported problems investigated during the study involved cardiovascular symptoms. Other side effects reported were psychiatric and neurological incidents, along with cases of cardiac arrest and sudden death.

Wide spread reports of side effects spurred the FDA to announce the launch of a dietary supplements adverse event reporting system in January of this year. The reporting system is designed to help the FDA detect supplements that pose a risk to the public, including excessive levels of caffeine.