Abstract:

The aim of this study was to investigate the acute effect of the combined consumption of glutamine and creatine on the performance of cyclists. Eight licensed, active, and trained male cyclists (age: 25.85 ± 9.75 years; height: 174.71 ± 5.18 cm; body weight: 69.81 ± 7.16 kg; body mass index (BMI): 22.95 ± 2.97 kg/m2; sports age: 5.28 ± 2.28 years) voluntarily participated in this study. In a randomized, single-blind, and cross-over design, the cyclists were randomly divided into 2 groups and performed the functional threshold power (FTP) test by taking glutamine&creatine (SUP) or placebo (PLA) at a 48-hour interval. The Borg Scale, Visual Analog Scale (VAS), and Gastrointestinal Symptom Rating Scale (GSRS) were utilized at the end of the tests. Between-group comparisons were analyzed with paired sample t-tests. Cohen’s d formula was applied to calculate the effect size. No statistical significance was found in heart rate (HR), cadence, FTP (average power, W, W/kg), rating of perceived exertion (RPE), and VAS values (p>0.05). Also, while there was a small effect size in cadence (0.34) and a large effect size in VAS (0.83) in favor of the SUP group, a medium effect size (0.61) was observed in RPE in favor of the PLA group. In GSRS results, no significant difference was observed between the groups (p>0.05). In conclusion, it was determined that glutamine&creatine coingestion had no acute effect on functional threshold power (FTP) and performance. However, it can be said that glutamine & creatine consumption has a positive effect on muscle pain.

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