Most cited article - PubMed ID 38226646
The dose-dependent effect of caffeine supplementation on performance, reaction time and postural stability in CrossFit - a randomized placebo-controlled crossover trial
BACKGROUND: CrossFitⓇ sessions and competitions are characterized by high-intensity challenges that combine aerobic and anaerobic activities with short recovery periods. As a result, effective nutritional practices play a crucial role in optimizing performance and enhancing recovery. Therefore, nutritional practices are central to optimizing performance and accelerating recovery. This review aims to summarize current evidence on nutritional and ergogenic aid responses to CrossFitⓇ practice. METHODS: The search was conducted in four electronic databases (PubMed, Web of Science, Scopus and SportDiscus). Gray literature was also extracted for studies exploring the nutritional habits of CrossFitⓇ participants as well as the ingestion of ergogenic aids. In addition, a meta-analysis was conducted to examine the impacts of dietary habits and ergogenic aids on performance. RESULTS: Forty-nine studies met the eligibility criteria and were included in the current review. Carbohydrate intake was below the recommendations for athletes, although protein ingestion remains adequate. High-carbohydrate diets had a positive effect on CrossFitⓇ performance. The evidence concerning the effects of a ketogenic diet on performance is limited. When used prior to or during the workout, the impact of carbohydrates on CrossFitⓇ performance was negligible, whereas the effect of caffeine was significant. Ergogenic aids, particularly creatine and protein, are commonly used by CrossFitⓇ participants. CONCLUSION: The standard diets recommended to CrossFitⓇ participants need to be revised because they are characterized by lower values of carbohydrates. Caffeine should be used prior to or during the CrossFitⓇ sessions. Regarding the impact of ergogenic aids on recovery, future studies are needed.
- Keywords
- Carbohydrates, caffeine, conditioning, energy, performance, strength,
- MeSH
- Diet MeSH
- Dietary Proteins administration & dosage MeSH
- Dietary Carbohydrates administration & dosage MeSH
- Sports Nutritional Physiological Phenomena * MeSH
- Diet, Ketogenic MeSH
- Caffeine administration & dosage MeSH
- Physical Conditioning, Human * MeSH
- Creatine administration & dosage MeSH
- Performance-Enhancing Substances administration & dosage MeSH
- Humans MeSH
- Athletic Performance * physiology MeSH
- Feeding Behavior MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Scoping Review MeSH
- Names of Substances
- Dietary Proteins MeSH
- Dietary Carbohydrates MeSH
- Caffeine MeSH
- Creatine MeSH
- Performance-Enhancing Substances MeSH
Twenty-eight endurance-trained males aged 31.1 ± 10.2 years (body mass [BM] 81.9 ± 9.0 kg) completed this randomized double-blind placebo (PLA)-controlled crossover study investigating the effect of 12-week Colostrum Bovinum (COL) supplementation (25gCOL·day-1) on aerobic fitness and capacity, time to exhaustion, BM and body composition (BC), and blood lactate concentration. There were four main-before/after supplementation study visits (COLPRE and COLPOST; PLAPRE, and PLAPOST). During study visits, BM and BC evaluation, incremental rowing test (IRT) to exhaustion, and evaluation of resting (REST) and post-exercise (POST-IRT) blood lactate concentration were performed. COL, but not PLA supplementation, significantly increased (p < 0.05) time to ventilatory threshold (TVT). Moreover, the implemented treatments had large (mL·min-1) and moderate (mL·min-1·kg-1) effects on oxygen uptake at VT (VO2VT), as well as moderate effect on power output at VT (PVT; W·kg-1) with the highest values observed at COLPOST visit. Neither significant influence of COL supplementation on time to exhaustion (TEXH) in IRT, BM, and BC on blood lactate was observed. Importantly, there were significantly (p < 0.05) higher increases in VO2VT (mL·min-1 and mL·min-1·kg-1) after COL compared to PLA supplementation. In summary, COL supplementation resulted in a favorable increase in TVT, and tended to improve some of the evaluated threshold indicators, namely VO2VT and PVT in endurance-trained male athletes during IRT. Therefore, COL supplementation may be considered as a support to improve aerobic fitness and capacity in endurance-trained males; however, supplementation strategy must be personalized and properly incorporated into the individual training. TRIAL REGISTRATION: The study protocol was registered at ClinicalTrials.gov (NCT06390670).
- Keywords
- ergogenic support, proteins, supplementation, swimming, triathlon,
- MeSH
- Adult MeSH
- Double-Blind Method MeSH
- Physical Endurance * MeSH
- Cross-Over Studies MeSH
- Colostrum * MeSH
- Lactic Acid blood MeSH
- Humans MeSH
- Young Adult MeSH
- Dietary Supplements * MeSH
- Body Composition * MeSH
- Oxygen Consumption MeSH
- Endurance Training * MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Randomized Controlled Trial MeSH
- Names of Substances
- Lactic Acid MeSH
BACKGROUND: Although caffeine (CAF) supplementation has been shown to improve exercise performance, its dose-dependent effect on CAF metabolism has not been sufficiently investigated. The aim of this study was to evaluate the effects of 3, 6 and 9 mg of CAF/kgBM on changes of CAF and paraxanthine (PRX) in the serum and saliva at four time-points. METHODS: In a randomized, double-blind, placebo-controlled crossover design, acute pre-exercise supplementation in 26 moderately-trained athletes, participating in high-intensity functional training (HIFT), was examined. The study protocol involved CAF/PRX biochemical analyses of serum and saliva with respect to CYP1A2 polymorphism and CYP1A2 enzyme activity. RESULTS: Despite significant differences between the serum and saliva levels of CAF and PRX, there was no difference in the PRX/CAF ratio. The interaction effect of dose and time-points for PRX concentration was revealed. The main effects of dose were observed for CAF and the PRX/CAF ratio. The main effect of time-points was registered only for serum CAF. CONCLUSIONS: Dose- and time-dependent effect of CAF supplementation on CAF and PRX in the serum and saliva of athletes was confirmed, but there was no effect of the CAF dose on CYP1A2 enzyme activity, nor was there an interaction of CYP1A2 with enzyme inducibility. The CAF/PRX correlation indicated the possibility of interchangeable use of serum and/or saliva analyses in exercise studies. CLINICAL TRIAL REGISTRATION: This trial was registered prospectively at ClinicalTrials.gov (NCT03822663, registration date: 30/01/2019).
- Keywords
- Enzyme activity, Ergogenic support, High-intensity functional training, Metabolism, Sports dietetics, Supplementation,
- Publication type
- Journal Article MeSH