Synergistic effects of caffeine, l -theanine, and diaphragmatic breathing on esports performance: A randomized controlled crossover trial
NUTRITION RESEARCH, cilt.151, ss.26-36, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 151
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.nutres.2026.04.007
- Dergi Adı: NUTRITION RESEARCH
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, CINAHL, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO)
- Sayfa Sayıları: ss.26-36
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
Esports athletes require exceptional cognitive and motor performance, particularly rapid reaction times (RTs). Although caffeine is widely recognized for its ergogenic effects, the benefits of combining caffeine with L-theanine or diaphragmatic breathing on esports performance have not been thoroughly examined. In this randomized, single-blind, three-arm crossover trial, 15 professional male esports athletes (mean age = 22.9 +/- 3.8 years) each received three interventions in randomized order: (1) caffeine only, (2) caffeine + L-theanine, and (3) caffeine + diaphragmatic breathing, with a 7-day washout period between sessions. Primary outcomes included auditory and visual RTs and Aim Lab performance scores. Statistical analysis was performed using the Friedman and Wilcoxon signed-rank tests with Bonferroni correction. Both caffeine + L-theanine and caffeine + diaphragmatic breathing significantly improved auditory RT compared to caffeine alone ( P = .027). AimLab scores also improved significantly in both combined intervention arms ( P = .015 and P = .006, respectively). Visual RT did not differ between conditions. These findings suggest that combining caffeine with either L-theanine or diaphragmatic breathing may offer synergistic cognitive benefits for esports athletes, particularly in enhancing auditory RT and precision, supporting in-game performance beyond caffeine supplementation alone. Trial Registration: This study was registered at ClinicalTrials.gov (ID: NCT06621797). (c) 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.