League of Legends (LoL) is one of the most popular video games, with 100 million monthly active players. The game requires mental functioning and cognitive abilities for success, and mental fatigue is a potential factor in performance. Some players turn to cognitive-enhancing drugs to gain an edge, and energy drinks are popular due to claims of reducing mental fatigue and improving performance through esports nutrition. 

In this study, researchers examined the effects of an ergogenic supplement on cognitive function and mental and physiological fatigue in a sample of elite esport players during a simulated competition. They hypothesized that mental fatigue from playing three consecutive video games would result in a decline in performance and that the use of an energy drink would reduce it.

The energy drink consisted of 12 g of glycerin, 150 mcg of vitamin B12, 70 mg of magnesium, 40 mg of sodium, and 1005 mg of a proprietary blend of L-Carnitine, 150 mg of caffeine, L-theanine, Phosphatidylserine, Choline (from alpha-GPC), and Nicotinamide Adenine Dinucleotide (reduced form NADH). The placebo drink was made from Crystal Light Pink Lemonade Drink Mix and was consumed in equal volume with the treatment drink. Participants were unable to guess which drink they received.

The cognitive measures included the Eriksen Flanker Test, the Go/No-go Visual Reaction Time Test, and the Working Memory Test (n-back), which were conducted using an online source. The physical measures included the handgrip dynamometer test, which measured grip strength, and the modified YMCA physical fitness test, which measured muscular endurance.

It’s important to consider confounding variables that impact cognitive function, including sleep, exercise frequency, and nutrition. The average sleep duration of the participants was 8.1 hours per night, and they reported playing 10.3 hours of League of Legends and 1.8 hours of other video games per day, with an average exercise frequency of 4.2 days per week. The self-assessment of diet quality revealed that only 4 of the participants felt they had a healthy diet.

The results showed that playing three consecutive LoL games did not result in an accumulation of mental fatigue, and the consumption of Reload did not improve performance parameters. The energy drink improved reaction time, accuracy, and working memory performance compared to the placebo, but did not have any effect on grip strength or muscular endurance. The study concludes that the energy drink may have the potential to enhance cognitive performance in LoL players.

The authors suggest that future research consider pre- and post-testing during an in-season competition to determine if there are greater signs of mental fatigue. Additionally, they suggest examining the relationship between BMI and esport performance, as well as determining the effects of dietary interventions on performance improvements.

1. The study showed that playing three consecutive League of Legends (LoL) games does not result in an accumulation of mental fatigue, and the consumption of an energy drink (Reload) did not improve performance parameters.

2. The study participants were elite LoL athletes who had an average age of 20.8 years and an average BMI of 25.6, which falls within the overweight category.

3. The study participants had a sleep and training schedule that exceeded the average American and made sleep and practicing LoL a priority.

4. A strength of the study was that it was the first to examine the effects of mental and physical characteristics relative to esport performance concurrent with the effects of ergogenically formulated nutrition supplementation on professional participants.

5. The study had several limitations, including the testing of professionals rather than amateurs, the use of a convenience sample of participants from the same team, and the low sample size of the study.

Based on these results, coaches can focus on creating a sleep and training schedule that prioritizes rest and training for their players. They can also encourage their players to assess and improve their diets to help with overall health and performance. However, it is important to keep in mind the limitations of the study and further research is needed to fully understand the effects of energy drinks and mental fatigue in esport performance

Thomas CJ, Rothschild J, Earnest CP, Blaisdell A. The Effects of Energy Drink Consumption on Cognitive and Physical Performance in Elite League of Legends Players. Sports (Basel). 2019 Aug 22;7(9):196. doi: 10.3390/sports7090196. PMID: 31443435; PMCID: PMC6784180.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6784180/

EHPI