CrossFit je všestranně orientovaný tréninkový program zaměřený na rozvoj celkové kondiční připrave-nosti. K získání titulu „Fittest on Earth“ musí účastníci projít tříkolovým eliminačním systémem (CrossFit Open, Regions, Games). Cílem studie je analýza vývoje počtu účastníků v letech 2011–2017 mužů (n = 1 012 297) a žen (n = 702 011) v prvním eliminačním kole a posouzení vhodnosti počtu postupových míst v jednotlivých regionech. Výzkumná data získaná z veřejně dostupných zdrojů prokázala vzrůsta-jící lineární vývojový trend počtu účastníků (R2 = 0,98–0,99), počet mužů byl v celém období vyšší oproti počtu žen. V kategorii Individual Men (IM) byl v regionu Evropa v roce 2017 zaznamenán nejvyšší počet účastníků (n = 40 716; tj. 0,006 % z obyvatel regionu), nejmenší počet účastníků byl v roce 2017 zjištěn v regionu Západní Kanada (n = 3 678, tj. 0,028 % z obyvatel regionu). V kategorii Individual Women (IW) byl v regionu Evropa v roce 2017 zaznamenán nejvyšší počet účastnic (n = 21 742, tj. 0,003 % z obyvatel regionu), nejmenší počet účastnic byl zjištěn v regionu Západní Kanada (n = 3 596, tj. 0,027 % z obyva-tel regionu). Nedostatek dobré shody počtu postupových míst byl v kategorii IM zjištěn v letech 2016 a 2017, v kategorii IW byla zjištěna dobrá shoda v celém sledovaném období 2011–2017. Test poměru šancí prokázal, že v roce 2017 měli účastníci ze Západní Kanady 12,22krát větší šanci na postup než účastníci z Latinské Ameriky, zatímco účastnice ze stejných regionů měly 7,03krát větší šanci na po-stup. S ohledem na zjištěné výsledky lze pro kategorii IM doporučit úpravu počtu postupových míst a rozdělení regionu Evropa.

CrossFit is an all-round training program focused on the development of overall fitness. To win the title “Fittest on Earth”, the participants must pass a 3-round elimination system (CrossFit Open, Regions, Games). The objective of the study is to analyze the development of participants' numbers in 2011–2017, men (n = 1 012 297) and women (n = 702 011), in 1st elimination round and to assess the appropriateness of the number of qualifying places in particular regions. The research data from public sources show a growing linear evolutionary trend in the number of participants (R2 = 0.98–0.99); the number of men was higher than the number of women through the whole period. In the category Individual Men (IM), the highest number of participants (n = 40 716; i.e. 0.006 % of the region population) was registered in the region Europe in 2017; the lowest number of participants (n = 3 678, i.e. 0.028 % of the region popu-lation) was found in West Canada in 2017. In the category Individual Women (IW), the highest number of participants (n = 21 742, i.e. 0.003 % of the region population) was registered in Europe in 2017; the lowest number of participants (n = 3 596, i.e. 0.027 %) was found in West Canada in 2017. The lack of good correspondence in the numbers of qualifying places was found in the IM category in 2016 and 2017; in the IW category, a good correspondence was found in the whole observed period 2011–2017. The odds ratio test has shown that in 2017, males from West Canada had 12.22 times bigger chance for qualifying than males from Latin America while females from the same regions had 7.03 times bigger chance for qualifying. In view of the results, it is possible to recommend an adjustment of the number of qualifying places and the division of the region Europe.

• Klíčová slova
• crossfit,
• MeSH
• cvičení MeSH
• lidé MeSH
• sportovci statistika a číselné údaje   MeSH
• tělesná a funkční výkonnost * MeSH
• tělesná výkonnost MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• hodnotící studie MeSH

• Publikační typ
• abstrakt z konference MeSH

PURPOSE CrossFit is a young sport discipline which offers varied strength and endurance training through complex exercises. Currently there are relatively few studies focusing on performance analysis in terms of the physiological response of organism. The aim of the research was to verify near infrared spectroscopy (NIRS) in combination with spiroergometry as a functional means for specific load testing in CrossFit. METHODS Elite crossfitter (male, age 20, body height 185 cm, body weight 87 kg) formed part of this study. Two Moxy sensors (placed on the vastus lateralis muscle and the intercostal muscles) and chest (strap) heart rate (HR) sensor were used for obtaining the data. The Cortex MetaMax 3BR2 system was used for portable spiroergometry. The AMRAP method (as many repetitions as possible) was used for testing. The selected test consisted of (1) 10 Deadlifts, 100kg, 15 Assault Air Bike Calories; (2) 12 lunges (with two 20 kg Kettlebell), 10 push-ups, 8 ring swings; (3) 20 SkiErg Calories, 10 50kg back squat, 10 toes to bar. RESULTS The testing has confirmed that breathing functions and muscle oxidation can be well observed under load in given exercises and movements. It has been confirmed that CrossFit provides a very varied load to which the organism must respond immediately. The strength load changes, causing deflection in SmO2 and VCO2 which consequently imposes demands on the respiratory component. CONCLUSIONS This is the first study which monitors the load in the combination of strength and endurance load through crossfit elements. Based on our result, it seems that linking NIRS and spirometry is a suitable combination for a comprehensive analysis of the athlete not only for CrossFit.

• Klíčová slova
• crossfit,
• MeSH
• cvičení MeSH
• ergometrie MeSH
• lidé MeSH
• spektrální analýza MeSH
• spirometrie MeSH
• sportovci MeSH
• zátěžový test MeSH
• Check Tag
• lidé MeSH

Východiska: Oblast fitness je příznačná častými změnami, objevují se nové trendy, metody nebo cviky. Současným trendem je „high intensity“ neboli způsob cvičení, který je spojen s vysokým úsilím, intenzivními prožitky, vysokou tepovou frekvencí apod. „High-intensity“ je zahrnuto do více oblastí a používáno širokou sportovní veřejností. Vzhledem k rozsáhlému využívání je důležité, aby terminologie byla používána a interpretována správně. Cíle: Vymezit vybrané aktuální pojmy spojené s „high intensity“ a zřetelně popsat jejich odlišnosti. Jednalo se o HIFT (high-intensity functional training), HIIT (high-intensity interval training), kruhový trénink, CrossFit® a funkční trénink. Metodika: Byla provedena literární rešerše v databázích Pubmed, Semantic scholar, Google scholar a Scopus. Využity byly i tuzemské nedigitalizované zdroje. Do analýzy byly zahrnuty pouze zdroje, u kterých bylo možné jasně určit použití daného pojmu. Výsledky a závěry: Vybrané pojmy byly vymezeny a zároveň byly popsány rozdílné znaky. Každý z uvedených pojmů má svá jasná specifika, a proto by neměly být zaměňovány nebo nevhodně použity. Vzhledem k neustálému vývoji ve fitness je nutné tento sektor stabilně sledovat i z pohledu terminologie.

Background: Frequent changes, new trends characterize the fitness industry, methods or exercises appear. The current trend is “high intensity”, or a way of exercising, associated with high effort, intense experiences, increased heart rate, etc. “High-intensity” is included in several areas and used by the general sporting public. Due to its widespread use, it is important that terminology is used and interpreted correctly. Objective: To define selected current concepts associated with “high intensity” and clearly describe their differences. These were HIFT (high-intensity functional training), HIIT (high-intensity interval training), circuit training, CrossFit, functional training. Methods: Literature research was performed in the databases Pubmed, Semantic scholar, Google scholar, Scopus. Domestic non-digitized sources were also used. Only sources for which the use of the term could be clearly identified were included in the analysis. Results and conclusions: Selected terms were defined, and at the same time, different attributes were described. Each of these terms has its precise specifics and should therefore not be confused or inappropriately used. Due to the constant development in the fitness industry, it is necessary to monitor this sector stably.

• MeSH
• cvičení MeSH
• lidé MeSH
• sportovní výkon MeSH
• sporty * MeSH
• Check Tag
• lidé MeSH

Východiska: Problematika dopingu se nevyhnula ani CrossFitu®, který představuje mladou progresivní sportovní disciplínu. Crossfitový výkon vyžaduje vysokou úroveň silových i vytrvalostních schopností, které jsou navíc v pestrých kombinacích. V posledních letech se nejen zvýšil počet pozitivně testovaných atletů, ale také se objevily nově používané látky SARM (selektivní modulátor androgenního receptoru) a PPARδ (receptory aktivované proliferátory peroxizomů). Jedná se o podpůrné prostředky, které jsou velmi dobře dostupné a představují tak zvýšené riziko. Cíle: Vytvořit seznam pozitivně testovaných atletů v CrossFitu®. Představit SARM a PPARδ, jejich účinky a možnosti zneužití. Metodika: Z oficiálních zpráv byl sestaven seznam atletů s dopingovým nálezem. Bylo provedeno review literatury týkající se vybraných SARM a PPARδ, vztahující se k danému tématu. K vyhledávání byly použity databáze Scopus, Web of Science, PubMed, Google scholar. Výsledky: PPARδ se ukazují jako účinný lék pro pacienty s diabetem II. typu nebo metabolickým syndromem. Mají funkci ve zvýšení oxidace mastných kyselin, transportu glukózy ve svalu. Dále přispívají ke zvýšení vytrvalostního výkonu. Potenciální vedlejší účinky jsou sice mírné, ale zasahují kosterní a oběhovou soustavu. SARM představují substituci anabolických steroidů. Prokazuje se jejich srovnatelná účinnost. Jejich vedlejší účinky jsou pravděpodobně mírnější, nicméně je zde zřejmý vliv na změnu lipidového nebo hormonálního spektra. U SARM je k dispozici velmi málo validních informací a provedených studií. Závěry: Na vzorku profesionálních atletů se ukazuje, že doping je aktuální téma v CrossFitu®. SARM a PPARδ nacházejí oblibu u uživatelů díky účinnosti, dostupnosti a relativně nízkým akutním vedlejším efektům. Obě látky sebou přinášejí zdravotní rizika a v mnohých ohledech nejsou zmapovány jejich dlouhodobé negativní účinky. V tomto ohledu je důležité nadále edukovat sportovní obec a upozorňovat na nové trendy ve zneužívání zakázaných látek.

Background: The issue of doping also concerns CrossFit®, which represents a young progressive sports discipline. CrossFit® performance requires a high level of strength and endurance skills, which are also in various combinations. Another attribute is the high intensity associated with high demands on subsequent regeneration. As it turns out, these aspects are well influenced by banned substances. Objective: In recent years, has not only the number of positively tested athletes increased, but also the newly used substances SARM (selective androgen receptor modulator) and PPARδ (peroxisome proliferator-activated receptors) have appeared. These are enhancing drugs that are very well available and thus pose an increased risk. Methods: A list of athletes with a doping finding was compiled from official reports. A literature review was performed on selected SARMs and PPARδ related to the topic. Scopus, Web of Science, PubMed, Google scholar databases were used for searching. Results: PPARδ has been shown to be an effective drug for patients with diabetes II. type or metabolic syndrome. They have a function in increasing the oxidation of fatty acids, the transport of glucose in muscle. They also contribute to improving endurance performance. Potential side effects are mild but affect the skeletal and circulatory system. SARMs are a substitution for anabolic steroids. Their comparable effectiveness is proven. Their side effects are probably milder, but there is a noticeable effect on the change in the lipid or hormonal spectrum. Very little valid information and studies are available for SARM. Conclusions: A sample of professional athletes shows that doping is a topical issue in CrossFit®. SARM and PPARδ are popular with users due to their efficacy, availability, and relatively low acute side effects. Both substances carry health risks, and in many respects, their long-term adverse effects are not known. In this regard, it is important to continue educating the sports community and drawing attention to new trends in doping.

• MeSH
• androgenní receptory MeSH
• cvičení * MeSH
• doping ve sportu * metody   prevence a kontrola   MeSH
• lidé MeSH
• receptory aktivované proliferátory peroxizomů MeSH
• sportovci MeSH
• sporty MeSH
• Check Tag
• lidé MeSH

In the basic principles of CrossFit®, the goal is to improve fitness, related to the simultaneous development of strength and endurance. This is also the main idea of concurrent training, which has been researched since the 1980s. This article aimed to analyze the acute and chronic effects of CrossFit® and to assess the relevance of using the concurrent training methodology. The findings show that CrossFit® is an intense form of exercise that affects the function of the endocrine, immune, and central nervous systems. It also has potential in the development of strength and endurance parameters. These conclusions were compared with relevant concurrent training studies. Although the CrossFit® interventions (workouts of the day) have much in common with concurrent training, methodological recommendations can only be partially transferred. The approach for training and athlete development must be based on the originality of this sport.

• MeSH
• fyzická vytrvalost MeSH
• kondiční příprava metody   MeSH
• lidé MeSH
• svalová síla MeSH
• tělesná výkonnost * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• systematický přehled MeSH

Background: There is a paucity of literature on the effects of fitness programs such as CrossFit (CF), Les Mills (LM), and traditional resistance training (TRAD) on sensorimotor responses, which define overall motor skills levels that are major factors in improving quality of life of fitness training practitioners. Objective: The purpose of this study was to assess and compare the sensorimotor responses after 16 weeks of CF, LM and TRAD trainings. Methods: A total of one hundred and seven sedentary participants (81 men, 26 women, age 30.5 ± 5.7 years, weight 78.9 ± 11.1 kg, height 174.9 cm, fat mass 25.4 ± 5.3%) were assigned randomly into 3 groups CF (n = 34), LM (n = 33) and TRAD (n = 40), they followed the training allocated at the rate of 5 sessions/week for 16 weeks. On three occasions: before (T0), after eight (T1) and sixteen weeks (T2) of training, participants underwent different tests of sensorimotor measures; coordination (Extremity Motor Coordination Test), accuracy (Motor Accuracy Test), agility (Illinois Agility Test) and balance (Y Balance Test).Results: Coordination improved only in the LM group for upper (T0-T1: p < .001, d = 0.09-0.13; T1-T2: p < .001, d = 0.16-0.18) and lower limbs coordination (T0-T1: p < .001, d = 0.16-0.25; T1-T2: p < .001, d = 0.24-0.26). Agility test showed improvements for LM (T0-T1: p < .001, d = 0.55; T1-T2: p < .001, d = 0.87) and CF (T0-T1: p = .002, d = 0.20; T1-T2: p < .001, d = 0.40) and no difference for TRAD. For balance, results showed improvements in lower limbs for CF (T0-T1: p < .001, d = 0.08-0.14, T1-T2: p < .001, d = 0.05-0.23) and TRAD (T0-T1: p ≤ .003, d = 0.05-0.08, T1-T2: p < .001, d = 0.08-0.13) and at T2 for LM (p = 0.04, d = 0.06-0.2), for the upper limbs, results showed improvements for CF (T0-T1: p < .001, d = 0.04-0.09; T1-T2: p < .001, d = 0.15-0.28), at T2 for TRAD (p = .01-.03, d = 0.03-0.10) and no difference for LM. For motor accuracy, results did not show any difference. Conclusions: CF and LM trainings helps develop agility; however, CF and TRAD are more oriented to balance while LM are to coordination improvement, all three trainings have no effect on motor accuracy.

• MeSH
• cvičení fyziologie   klasifikace   MeSH
• dospělí MeSH
• lidé MeSH
• motorické dovednosti MeSH
• odporový trénink klasifikace   metody   MeSH
• sedavý životní styl * MeSH
• senzorická zpětná vazba MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• klinická studie MeSH

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

This interventional study examined the effect of a four-week vegan diet (VegD) during a four-week high-intensity functional training (HIFT) on performance, training results and blood biochemical indices in female (n = 12) and male (n = 8) moderate-trained CrossFit participants. The whole study group performed the maximum number of repetitions with a load of 70% one repetition-maximum (1RM) and a modified Fight Gone Bad (FGBMod) test before and after a dietary intervention (the group was divided to follow a VegD or a traditional mixed diet (MixD)) in a randomised and parallel design. Pre-exercise resting blood samples were also analysed. There was a significant improvement in the number of repetitions performed at a load corresponding to 70% of 1RM in the classic squat in the MixD group (p < 0.001), and in the classic deadlift in the VegD group (p = 0.014). Furthermore, there was a significant improvement in the results of the FGBMod performance test after a MixD. Moreover, an improvement in some exercises in the modified FGBMod test (Wall Ball after the VegD and the MixD, and rowing after the MixD) was also observed. However, differences between the MixD and the VegD groups were not clinically relevant. In conclusion, the short-term study conducted here indicated that a VegD in HIFT training positively affects strength endurance in the classic deadlift but is unlikely to be more beneficial in improving performance than a MixD.

• MeSH
• cvičení MeSH
• dieta veganská * MeSH
• kosterní svaly MeSH
• lidé MeSH
• odporový trénink * MeSH
• svalová síla MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• randomizované kontrolované studie MeSH

BACKGROUND: Because betaine (BET) supplementation may improve muscular strength and endurance, it seems plausible that BET will also influence CrossFit performance (CF). PURPOSE: The aim of this study was to evaluate the effects of three weeks of BET supplementation on body composition, CF performance, muscle power in the Wingate anaerobic test (WAnT), and the concentrations of selected hormones. The secondary aims were to analyze the effectiveness of two different BET doses (2.5 and 5.0 g/d) and their interaction with the methylenetetrahydrofolate reductase (MTHFR) genotype. METHODS: The study was designed in a double-blinded randomized cross-over fashion. Forty-three CF practitioners completed the entire study. CF performance was measured using the Fight Gone Bad (FGB) workout and muscle power was evaluated in a 30-second WAnT. Body composition was determined by air-displacement plethysmography. Blood was drawn to assess hormone concentrations. The C677T single nucleotide polymorphism (rs180113) in the MTHFR gene was analyzed. RESULTS: FGB total improved with BET by 8.7 ± 13.6% (p < 0.001), but no significant changes were observed with placebo (- 0.4 ± 10.0%, p = 0.128). No changes were also observed in WAnT and body composition. After BET supplementation testosterone concentration increased by 7.0 ± 15.4% with BET (p = 0.046) (no change with placebo: 1.5 ± 19.6%, p = 0.884) but had no effect on concentrations of insulin-like growth factor or cortisol. Finally, there were no significant interactions between MTHFR genotype and BET dose in any outcome. CONCLUSIONS: BET supplementation may improve CF performance and increase testosterone concentration. However, there was no evidence of a difference between dosages (2.5 and 5.0 g/d) and MTHFR genotypes. The trial was registered on clinicaltrials.gov (NCT03702205) on 10 October 2018.

• MeSH
• betain * farmakologie   MeSH
• dvojitá slepá metoda MeSH
• klinické křížové studie MeSH
• lidé MeSH
• potravní doplňky MeSH
• testosteron * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• randomizované kontrolované studie MeSH