The dose-dependent effect of caffeine supplementation on performance, reaction time and postural stability in CrossFit - a randomized placebo-controlled crossover trial.

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.

Dose-dependent effect of caffeine supplementation on judo-specific performance and training activity: a randomized placebo-controlled crossover trial.

BACKGROUND: Caffeine (CAF) supplementation could have a positive impact on physical performance and sport abilities. Nevertheless, the CAF-induced, dose-dependent influence on discipline-specific performance and combat activity in combat sports have not been sufficiently investigated. The aim of this study was to examine the effect of single ingestion of 3, 6, or 9 mg/kg body weight of CAF and placebo (PLA) on judo-specific performance and sparring combat activities. METHODS: In a randomised double-blind placebo-controlled cross-over design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body weight) and placebo PLA in 22 male highly-trained judoists was examined. The study protocol involved five separate testing sessions using the Special Judo Fitness Test (SJFT) with heart rate monitoring, three judo sparring combats and evaluation of the rate of perceived exertion (RPE) using the Borg scale. RESULTS: Six and 9 mg/kg CAF improved SJFT performance, while 9 mg/kg increased combat activity. Three mg/kg CAF lacked any apparent positive ergogenic effect. Among athletes, who include CAF-containing products in their habitual diet (consumers), only 9 mg/kg CAF effectively enhanced SJFT performance, while in those who do not consume CAF-containing products at regular basis (non-consumers), the enhancing effect was achieved even at 6 mg/kg. CONCLUSIONS: Regarding combat sports, higher (6-9 mg/kg) than currently recommended CAF dosages (3-6 mg/kg) are apparently more effective in terms of judo-specific performance. However, the ergogenic CAF effect is not only dose-dependent, but it is also related to customary CAF consumption. TRIAL REGISTRATION: Clinical Trials Gov, NCT03822663 . Registered 28 January 2019 - Retrospectively registered.

Consumption of cranberry functional beverage reduces gingival index and plaque index in patients with gingivitis.

Periodontal disease is highly prevalent worldwide, and consumption of certain foods, such as fruits, seem to improve the effectiveness of periodontal therapy (PT) due to their antiadhesive, immunomodulatory, and antioxidative properties. We hypothesized that the cranberry functional beverage (CFB) consumed for eight weeks improves gingival inflammation indices via inhibition of dental plaque, and alterations in antioxidant status, and systemic inflammation in patients with gingivitis. In this two-arm randomized controlled study, fifty participants were divided into an experimental group (CFB), administered daily with 750 ml CFB, or a control group administered the same amount of water. All patients underwent nonsurgical PT prior to the intervention. Gingival (GI) and bleeding on probing (BoP) indices of inflammation, plaque (PI) and approximal plaque (API) indices of dental plaque deposition, saliva and serum total antioxidant status (TAS), serum malonylodialdehyde level (MDA), and interleukin 1-beta level (IL-1beta) were measured pre- and postintervention. A risk of caries development was determined by Streptococcus mutans (SM) and Lactobacillus spp. (LAB) counts in supragingival dental plaque. Changes in GI and PI but not BoP and API were significantly more pronounced in the CFB group compared to the control group. Serum or saliva TAS, IL-1beta, and MDA did not differ between groups. The number of SM reduced in CFB, but not in the control group. We demonstrated that the consumption of CFB improves gingival and plaque indices without posing a risk of caries development. Thus CFB can be recommended as a safe adjunct for nonsurgical PT in patients with gingivitis.