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.

Practical Application and Methodological Considerations on the Basics of Sports Nutrition in Basketball: A Comprehensive Systematic Review of Observational and Interventional Studies.

The current systematic review (PROSPERO registration no. CRD42022334707) of observational (OS) and interventional studies (IS) aimed at evaluating the state of scientific knowledge on the basics of sports nutrition, framing discipline-specific dietary recommendations, and indicating potential directions for future studies in various age, experience level, and able-bodied abilities groups of basketball players (BP). A systematic search of PubMed, SPORTDiscus, and Web of Science ended on 20 December 2022. Records were excluded if reporting studies on animals, sport disciplines other than basketball, or supplementation protocols other than those related to macronutrients and hydration manipulations. Risk of bias (RoB) was evaluated using Cochrane RoB_2 tools, 'JBI checklist for prevalence studies', and 'Quality assessment tool for before-after (pre-post) studies with no control group'. The relevant data was synthesized in tables and a narrative review was performed. Seventy-two records were included (2581 participants): 63 were on able-bodied BP (2433 participants) and 9 on para-athlete players (148 participants); 45 records were OS and 27 IS. The review disclosed widespread poor nutritional habits and knowledge and shortages in applying adequate nutritional and hydration practices in BP. Moreover, the systematic review revealed the lack of a sufficient number of investigations delivering reliable proof for framing discipline-specific and evidence-based recommendations on the basics of sports nutrition in basketball.

The interplay between bicarbonate kinetics and gastrointestinal upset on ergogenic potential after sodium bicarbonate intake: a randomized double-blind placebo-controlled trial.

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.

Do Triathletes Periodize Their Diet and Do Their Mineral Content, Body Composition and Aerobic Capacity Change during Training and Competition Periods?

The triathlon is a demanding endurance multisport, which may strongly affect the nutritional status of athletes. The aim of this study was to find whether there are any differences in energy value and nutrient intake, body mass and body composition, aerobic performance and hair mineral status between training and competition periods and to assess whether there is a link between hair mineral content and physical capacity and nutrition. This observational study covered 20 triathletes aged 32 ± 7 years. The results of our study indicated performance improvement during the competition period (longer time to exhaustion (p = 0.025) and lower maximal oxygen uptake at the ventilatory threshold (%VO2max_VT; p = 0.047)). However, no differences were recorded in nutrition and body composition between two training vs. competition periods. There was a significant depletion in hair iron content during the competition period (p = 0.010). Furthermore, there were significant relationships between hair calcium content and absolute maximal oxygen uptake and %VO2max_VT during the training period. It is necessary to introduce nutritional education in the group of triathletes focused on exercise-oriented nutritional periodization following the requirements of the training and competition periods, thus preventing the risk of nutrient deficiencies.

The effect of cranberry juice and a cranberry functional beverage on the growth and metabolic activity of selected oral bacteria.

BACKGROUND: The oral microbiota is a significant risk indicator for oral diseases, such as dental caries and periodontal inflammation. Much attention is presently paid to the development of functional foods (e.g. beverages containing cranberry constituents, or foods containing probiotics) that may serve as adjuncts for oral disease treatments (e.g. periodontitis and caries). Cranberry fruit, due to its unique chemical composition and antimicrobial potential, is a possible ingredient of such foods. The study aimed to investigate the effects of cranberry juice (CJ) and a cranberry functional beverage (mixture of 80% v/v apple juice, 20% v/v cranberry juice, and 0.25 g/100 mL ground cinnamon; CFB) on the growth and metabolic activity of selected oral bacteria. METHODS: Serial dilution pour plate method (SDPP) was used to examine the effect of CJ and CFB on the growth of Actinomyces naeslundii, Streptococcus mutans, and Lactobacillus paracasei subsp. paracasei. 48-h electrical impedance measurements (EIM) during the cultivation of A. naeslundii were applied to evaluate the utility of the method as a rapid alternative for the assessment of the antimicrobial potential of cranberry beverages. RESULTS: The tested bacteria differed in their susceptibility to the antimicrobial action of CJ and CFB, with L. paracasei subsp. paracasei being least vulnerable to CFB (according to SDPP). Although CJ at a concentration of 0.5 mL/mL, showed a bactericidal effect on the growth of S. mutans, A. naeslundii was more sensitive to CJ (SDPP). Its inhibitory effect on A. naeslundii was seen even at concentrations as small as 0.03125-0.125 mL/mL (SDPP and EIM). On the other hand, S. mutans seemed to be more vulnerable to CFB than A. naeslundii (SDPP). CONCLUSIONS: CFB may be considered an adjunct in the treatment of oral diseases due to its action against selected oral pathogens, and not against the presumably beneficial L. paracasei subsp. paracasei. Bioelectrical impedance measurements appear to be a quick alternative to evaluating the antimicrobial activity of fruit beverages, but their utility should be confirmed with tests on other bacteria.

Is a Four-Week Ketogenic Diet an Effective Nutritional Strategy in CrossFit-Trained Female and Male Athletes?

This single-arm interventional study examined the effect of a 4-week ketogenic diet (KD) on aerobic capacity and discipline-specific performance in female (n = 11) and male (n = 11) CrossFit-trained athletes. The participants performed incremental cycling (ICT) and Fight Gone Bad (FGB) tests after consuming a customary diet and a KD. Pre- and post-ICT exercise blood samples were also analysed. Consuming a KD had a slight impact on aerobic capacity and no relevant effect on CrossFit-specific performance. In females, consuming a KD led to an 10.4% decrease in peak oxygen uptake during the ICT (p = 0.027) and resulted in certain alterations in haematological parameters (haemoglobin (HGB), mean corpuscular HGB, and mean corpuscular HGB concentration). Furthermore, in males, alanine aminotransferase activity increased with a simultaneous improvement in the post-ICT blood acid-base balance after consuming a KD. The pre-exercise bilirubin concentration was also elevated in the entire group after consuming a KD. In conclusion, female CrossFit-trained athletes seem to be prone to aerobic performance decrements and increased risk of developing haematological disturbances when consuming a KD. In males who consumed a KD, there was an undesirable alanine aminotransferase elevation and a small tendency towards improved acid-base status. Moreover, consuming a KD had no effect on discipline-specific performance in CrossFit-trained athletes.

The influence of progressive-chronic and acute sodium bicarbonate supplementation on anaerobic power and specific performance in team sports: a randomized, double-blind, placebo-controlled crossover study.

BACKGROUND: The aims of this study were to verify the effect of progressive-chronic and acute sodium bicarbonate (SB) supplementation on the anaerobic capacity, blood acid-base balance, and discipline-specific performance in team sports disciplines. METHODS: Twenty-four trained male field hockey players completed a randomized, placebo-controlled, crossover trial of either progressive-chronic (increments from 0.05 up to 0.2 g/kg) or an acute one-off dose (0.2 g/kg) supplementation protocol. Before and after treatments, athletes completed an exercise protocol that comprised of a discipline-specific field performance test conducted between two separate Wingate anaerobic tests (WAnTs). RESULTS: Progressive-chronic SB supplementation improved anaerobic capacity in the first bout of WAnTs, as observed based on an increase in mean power (MP: 575 ± 71 vs. 602 ± 67 W, p = 0.005, ~ + 4.7%), peak power (PP: 749 ± 94 vs. 777 ± 96 W, p = 0.002, ~ + 3.7%), power carry threshold (PCT) at 97%PP (727 ± 91 vs. 753 ± 93 W, p = 0.002, ~ + 3.6%) and average power over PCT (739 ± 94 vs. 765 ± 95 W, p = 0.001, ~ + 3.5%). Acute SB supplementation had no effect on anaerobic capacity. However, an improvement in time during discipline-specific field performance test was observed after progressive-chronic (919 ± 42 vs. 912 ± 27 s, p = 0.05; ~ - 0.8%) and acute (939 ± 26 vs. 914 ± 22 s, p = 0.006, ~ 2.7%) SB supplementation. Acute SB supplementation also improved post-exercise parameters of acid-base balance (based on blood pH, bicarbonate concentration and base excess) compared to no supplementation or placebo. CONCLUSIONS: Our study indicates that both chronic and acute SB supplementation positively supports discipline-specific performance among field hockey athletes. Moreover, the chronic protocol supported anaerobic power indices before the inset of exercise-induced fatigue but had no significant impact afterwards. However, only the acute protocol significantly affected the buffering capacity, which can be used to determine athlete's performance during high-intensity sporting events. This study design therefore highlighted that future studies focusing on sodium bicarbonate supplementation in team sports should concentrate on the efficiency of chronic and acute supplementation in varying time frames.

Relationship between body composition and the level of aerobic and anaerobic capacity in highly trained male rowers.

BACKGROUND: Body composition may affect the potential for success in sports. For this reason, our study aimed to determine the impact of body composition on the level of aerobic and anaerobic capacity in competitive rowers. METHODS: The study involved 48 males aged 20±2 years. Body composition was analysed using electrical bioimpedance. Maximum aerobic capacity (VO2max) and average anaerobic power (AP) were determined using an incremental cycling test until exhaustion and a standard Wingate Anaerobic Test (WAT), respectively. RESULTS: The optimal ranges of body components with respect to the level of anaerobic and aerobic capacity at preparatory period for highly trained rowers aged 17-23 years, with body mass 67.5-104.7 kg, were 86-88% for fat free mass (FFM), 63-65% for total body water (TBW) and 11-13% for fat mass (FM). Regression analyses showed that BM and FFM significantly contributed to the prediction of VO2max and AP. The increase in FFM and BM by 1 kg resulted in the change of VO2max by +0.161 l.min-1 and -0.057 l.min-1, and AP by +5.51 W and +4.74 W, respectively. CONCLUSIONS: Body composition is closely related to the level of aerobic and anaerobic capacity in rowers, and we suggest that its regulation can serve as an effective tool to improve physical performance. The regression models we developed seem to be promising for estimating the changes in physical capacity based on body composition modifications, however, their accuracy should be verified in an experimental study.

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.

Effect of a four-week ketogenic diet on exercise metabolism in CrossFit-trained athletes.

BACKGROUND: The ketogenic diet is becoming a popular nutritional model among athletes. However, the relationship between its use and metabolism during exercise seems to have not been fully investigated. METHODS: The aim of the study was to assess the effects of a four-week ketogenic diet (KD) on fat and carbohydrate (CHO) utilization during an incremental cycling test (ICT) in CrossFit-trained female (n = 11) and male (n = 11) athletes. During the ICT (while consuming the customary diet and after the KD), oxygen uptake and carbon dioxide exhalation were registered, and CHO and fat utilization as well as energy expenditure were calculated. RESULTS: In males, the KD led to an increase in fat utilization (g·min- 1·kgFFM- 1 and % oxidation). It was particularly noticeable at exercise intensities up to 80% of VO2max. An increase in the area under the curve (AUC) was seen in males but not in females at up to ≤65% VO2max of fat utilization. CONCLUSIONS: Male CrossFit-trained athletes seem to be more prone to shifts in macronutrient utilization (in favor of fat utilization) during submaximal intensity exercise under a ketogenic diet than are female athletes. TRIAL REGISTRATION: Clinical Trials Gov, NCT03665948 . Registered 11 September 2018 (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.