BACKGROUND: Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime), postural stability (PStab), heart rate (HR) and perceived exertion (RPE). METHODS: In a randomized double-blind placebo-controlled crossover design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body mass (BM)) and PLA in 26 moderately trained CrossFit practitioners was examined. The study protocol involved five separate testing sessions using the Fight Gone Bad test (FGB) as the exercise performance evaluation and biochemical analyses, HR and RPE monitoring, as well as the assessment of RTime and PStab, with regard to CYP1A2 (rs762551) and ADORA2A (rs5751876) single nucleotide polymorphism (SNP). RESULTS: Supplementation of 6 mgCAF/kgBM induced clinically noticeable improvements in FGBTotal results, RTime and pre-exercise motor time. Nevertheless, there were no significant differences between any CAF doses and PLA in FGBTotal, HRmax, HRmean, RPE, pre/post-exercise RTime, PStab variables or pyruvate concentrations. Lactate concentration was higher (p < 0.05) before and after exercise in all CAF doses than in PLA. There was no effect of CYP1A2 or ADORA2A SNPs on performance. CONCLUSIONS: The dose-dependent effect of CAF supplementation appears to be limited to statistically nonsignificant but clinically considered changes on specific performance, RTime, PStab, RPE or HR. However, regarding practical CAF-induced performance implications in CrossFit/HIFT, 6 mgCAF/kgBM may be supposed as the most rational supplementation strategy.
- MeSH
- cytochrom P-450 CYP1A2 MeSH
- dvojitá slepá metoda MeSH
- klinické křížové studie MeSH
- kofein * farmakologie MeSH
- kyselina mléčná MeSH
- lidé MeSH
- polyestery MeSH
- potravní doplňky MeSH
- reakční čas MeSH
- sportovní výkon * fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
One of the least invasive sampling methods suitable for self-sampling is saliva spitting. The aim of this study is to evaluate the suitability of saliva self-sampling for unsupervised testing. Two self-sampling strategies were compared on the basis of visual evaluation of samples, measurement of cortisol levels in samples and questionnaire survey. The saliva samples obtained by supervised self-sampling were found to be fully suitable for further analysis. In contrast, not all saliva samples obtained from unsupervised self-collection can be used: 13% non-compliance with the minimum required sample volume, 8% with some food/drink residues and 26% taken at the wrong day time. About 42% of the unsupervised probands made at least one significant error in the saliva self-collection procedure. These results indicate that the accuracy of the results based on the analysis of samples received from saliva self-sampling is limited. For clinical investigation, the presence of an inner standard (referring to the reliability of the sampling procedure) is required.
This double-blind placebo-controlled cross-over study utilized comprehensive monitoring of blood bicarbonate (HCO3 ̄) kinetics and evaluation of gastrointestinal (GI) upset to determine their impact on an ergogenic potential of sodium bicarbonate (SB) co-ingested with carbohydrate (CHO). Nineteen CrossFit athletes performed 6 bouts of 15 s Wingate Anaerobic Test (WAnT) 90 min post-ingestion of 0.4 g·kg-1 body mass (BM) of SB (SB + CHO treatment) or PLA (PLA + CHO treatment) with 15 g CHO. Blood HCO3 ̄ concentration was evaluated at baseline, 30-, 60-, 75- and 90 min post-ingestion, in between WAnT bouts, and 3 and 45 min post-exercise, while GI upset at 120 min after protocol started. Control (no supplementation; CTRL) procedures were also performed. An effective elevation of extra-cellular buffering capacity was observed 60-90 min post-ingestion of SB + CHO. At mean peak blood HCO3 ̄, or at start of exercise an increase > 6 mmol·L-1 in HCO3 ̄ was noted in 84% and 52.6% participants, respectively. SB + CHO did not prevent performance decrements in WAnT bouts. There were no significant relationships between changes in blood HCO3 ̄ and WAnTs' performance. Total GI was significantly higher in SB + CHO compared to CTRL, and stomach problems in SB + CHO compared to CTRL and PLA + CHO. There were inverse associations between peak- (p = 0.031; r = - 0.495), average- (p = 0.002; r = - 0.674) and minimum power (p = 0.008; r = - 0.585) and total GI upset, as well as average power and severe GI distress (p = 0.042; r = - 0.471) at SB + CHO. The implemented dose of SB + CHO was effective in improving buffering capacity, but did not prevent decrements in WAnTs' performance. GI side effects were crucial in affecting the ergogenic potential of SB and thus must be insightfully monitored in future studies.
- MeSH
- dvojitá slepá metoda MeSH
- gastrointestinální nemoci * chemicky indukované MeSH
- hydrogenuhličitan sodný škodlivé účinky MeSH
- hydrogenuhličitany MeSH
- klinické křížové studie MeSH
- lidé MeSH
- polyestery MeSH
- sportovní výkon * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
