Research on the external physical load on elite youth soccer players during the weekly training microcycle in competitive periods and official matches is limited. The aims of this study were twofold: a) investigate possible differences in external physical load (PL) across player positions in U17 elite youth soccer players during official matches; b) determine the weekly training to match physical load ratio (WTMLr) across player positions. The sample included 20 outfield players from an elite soccer academy (mean age 15.94 ± 0.25 years) playing in four positions: central defender (CD), full-back (FB), central midfielder (CM) and Striker (S). Data were collected during the spring in-season period for 17 official matches played in a 4-3-3 game format. Indicators of external physical load monitored were: total distance (TD); total distance in high-speed running (HSR; > 16.1 km.h-1); total distance in sprint running (SPR; > 21.6 km.h-1); and relative physical load intensity (%HSR). The WTMLr was calculated for TD, HSR, SPR and %HSR as the ratio of the average weekly sum of training PL to the average sum of PL in an official match for a given players' position. Collectively, the training intensity during a one-week microcycle (%HSR in WTMLr) achieved only 76 % of match demands. CD performed significantly lower in all measured indicators of external PL during the official match than all other positions (p < 0.05; g > 0.80) except for TD in S. S achieved significantly higher SPR during official matches compared to CD (p < 0.05; g > 0.80), CM, and FB (g > 0.80). In contrast, CD reported higher WTMLr (medium-large effect size) in HSR and SPR indicators than all other positions. CM performed significantly higher %HSR in WTMLr than S and FB (p < 0.05; g > 0.80). Results revealed insufficient training intensity relative to match demands and, at the same time, weekly training PL did not meet match demands (especially in HSR and SPR) for players across the different positions. Therefore, practitioners should select appropriate training methods (drills and games) to ensure sufficient training intensity (HSR and SR metrics) and consider using the WTMLr, which can be used to help optimise and individualise training PL for different player positions.
Normal-weight obesity appears to be an extended diagnosis/syndrome associated with insufficient physical fitness levels and inadequate eating habits at least from school years. However, its relation to long term health parameters in pre-school children remains unknown, even though pre-school age is crucial for the determining healthy lifelong habits. Therefore, the aim of the current study was to investigate the differences in physical fitness level and basic eating habits between normal-weight obese, normal-weight non-obese, and overweight and obese preschoolers. The research sample consisted of 188 preschoolers aged 4.0-6.9 years (Mage = 5.52 ± 0.8 year), normal-weight obese = 25; normal-weight non-obese = 143, overweight and obese = 20. Body composition was measured using bio-impedance InBody230. Six tests assessed the physical fitness level: sit-ups; standing long jump; shuttle running 4 × 5 meters; throwing with a tennis ball; multistage fitness tests; sit and reach. A four-item eating habits questionnaire for parents focusing on breakfast regularity, consumption of sweet foods and drinks, selection of food and attitude towards eating was used. A non-parametric analysis of variance and Fisher's exact test along with suitable effect sizes were used for data processing of physical fitness tests and the basic eating habits questionnaire, respectively. Normal-weight obese children performed significantly worse (from p = 0.03 to p < 0.001, ES ω2-G = low to medium) in muscular fitness, cardiorespiratory fitness and running agility compared to normal-weight non-obese counterparts and did not significantly differ in the majority of physical fitness performance tests from overweight and obese peers. In basic eating habits, normal-weight obese boys preferred significantly more sweet foods and drinks (p = 0.003 ES = 0.35, large), while normal-weight obese girls had significantly more negative attitude towards eating (p = 0.002 ES = 0.33, large) in comparison to their normal-weight non-obese peers. Normal-weight obesity seems to develop from early childhood and is associated with low physical fitness and deficits in eating habits which might inhibit the natural necessity for physically active life from pre-school age or sooner.
- MeSH
- cvičení MeSH
- dítě MeSH
- lidé MeSH
- obezita dětí a dospívajících epidemiologie etiologie MeSH
- ochrana veřejného zdraví MeSH
- předškolní dítě MeSH
- průřezové studie MeSH
- průzkumy a dotazníky MeSH
- školy MeSH
- stravovací zvyklosti * MeSH
- tělesná hmotnost * MeSH
- tělesná výkonnost * MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Despite the health-related implications of normal-weight obesity in children, very little research has explored the fundamental associations between this status and important long-term health parameters. Therefore, the aim of the current study was to investigate the physical fitness of children with normal-weight obesity, in comparison to normal-weight non obese and overweight and obese counterparts. A total of 328 middle-school-aged children (9.8 ± 0.5 y) took part in this study (n = 44 normal-weight obese; n = 237; normal-weight non obese; n = 47 overweight and obese). Height, weight, and body-fatness were measured. Four physical fitness tests were conducted: (1) Multistage fitness test; (2) shuttle run 4 × 10 m; (3) sit-ups for 60 s; (4) the broad jump. Welch's analysis of variance (ANOVA), stratified by sex, with post-hoc testing where necessary, was performed. Children with normal-weight obesity had significantly (p < 0.01) lower cardio-respiratory and muscular fitness than normal-weight non obese peers. In addition, normal-weight obese and overweight and obese boys had comparable deficits in strength and explosiveness of lower limbs, speed coordination, and endurance, compared to normal-weight non obese counterparts. Normal-weight obese children appear to have similar deficits in PF as their overweight and obese peers, compared to normal-weight non obese counterparts, whilst boys had larger deficits than girls.
- MeSH
- dítě MeSH
- kardiorespirační zdatnost * fyziologie MeSH
- lidé MeSH
- nadváha epidemiologie MeSH
- obezita dětí a dospívajících * epidemiologie MeSH
- průřezové studie MeSH
- sexuální faktory MeSH
- svalová síla * fyziologie MeSH
- tělesná hmotnost MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
High-intensity interval training (HIIT) is frequently utilized as a method to reduce body mass. Its intensity of work results in a number of beneficial adaptive changes in a relatively short period of time. Irisin is a myokine and adipokine secreted to the blood during exercise and it takes part in the regulation of energy metabolism. It is a vital issue from the prophylaxis point of view as well as treatment through exercise of different diseases (e.g., obesity, type-2 diabetes). The aim of this study was to evaluate changes in irisin concentration, body composition, and aerobic and anaerobic performance in men after HIIT. Eight weeks of HIIT following the Tabata protocol was applied in the training group (HT) (n = 15), while a sedentary group (SED) (n = 10) did not participate in fitness activities within the same time period. Changes of irisin, body composition, and aerobic and anaerobic performance were evaluated after graded exercise test (GXT) and Wingate anaerobic test (WAnT) before and after eight weeks of training. Training resulted in an increased of blood irisin concentration (by 29.7%) p < 0.05), VO2max increase (PRE: 44.86 ± 5.74 mL·kg-1·min-1; POST: 50.16 ± 5.80 mL kg-1·min-1; p < 0.05), reduction in percent body fat (PRE: 14.44 ± 3.33%; POST: 13.61 ± 3.16%; p < 0.05), and increase of WAnT parameters (p < 0.05) in the HT group. No changes were observed in the SED group. HIIT resulted in beneficial effects in the increase in blood irisin concentration, physical performance, and reduced fat content. The HIIT may indicate an acceleration of base metabolism. This effect can be utilized in the prevention or treatment of obesity.
- Publikační typ
- abstrakt z konference MeSH
The nutrition of soccer players is an important topic and its knowledge may help to increase the quality of this popular game and prevent possible health problems and injuries in players. This meta-analysis aims to estimate the current dietary trends of three basic macronutrients in junior and senior soccer players during the first two decades of the 21st century. We analyzed data from 647 junior players (mean age 10.0-19.3) from 27 groups, and 277 senior (mean age 20.7-27.1) players from 8 groups from altogether 21 papers in this meta-analysis. Weighted averages were calculated for each macronutrients. Protein intake is higher than recommended in both juniors, 1.9 95% confidence interval (CI) 1.8-2.0 g/kg/day, and seniors 1.8 95% CI 1.6-2.0 g/kg/day. However, carbohydrate intake is still below the recommended values in both groups (5.7 95% CI 5.5-5.9 g/kg/day in junior and 4.7 95% CI 4.3-5.0 g/kg/day in senior players). The proportion of fat as total energy intake is in concordance with the recommendations (31.5 95% CI 32.0-35.9% in junior and 33.1 95% CI 29.9-36.2% in senior players). In particular, due to possible health complications, the small carbohydrate intake should be alarming for coaches, nutritional experts, and parents.
- MeSH
- dieta * MeSH
- dietní proteiny aplikace a dávkování MeSH
- dietní sacharidy aplikace a dávkování MeSH
- dietní tuky aplikace a dávkování MeSH
- dítě MeSH
- dospělí MeSH
- energetický příjem MeSH
- fotbal * MeSH
- fyziologie sportovní výživy MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nutriční nároky * MeSH
- sportovci MeSH
- stravovací zvyklosti * MeSH
- výživová politika MeSH
- živiny MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
Fundamental motor skills (FMS) are the basic elements of more complex sport-specific skills and should be mastered at the end of early childhood; however, the relationship between FMS and sport-specific skills has not yet been verified in prepubertal soccer players. Therefore, the aim of this study was to determine the role of FMS in the process of acquiring soccer-specific motor skills (measured using speed dribbling) with regard to physical fitness and biological maturation. Forty male soccer players (11.5 ± 0.3 years of age) at the highest performance level participated in the study. The test of Gross Motor Development - second edition and Unifittest 6-60 were used to assess FMS and physical fitness, respectively. The role of FMS in a complex theoretical model with the relationships between physical fitness, biological maturation and speed dribbling was analyzed by multiple regression path analyses (MRPA). Moderate to strong correlations were found between FMS, physical fitness, and speed dribbling (r = 0.56-0.66). Biological maturation did not appear to be a significant predictor of physical fitness or speed dribbling. The MRPA model using FMS as mediator variable between physical fitness and speed dribbling showed a significant indirect effect (standard estimation = -0.31, p = 0.001; R2 = 0.25). However, the direct correlation between physical fitness and speed dribbling was non-significant. Our results showed that FMS significantly strengthened the influence of physical fitness on the performance of speed dribbling, a soccer-specific motor skill, and thus play an important role in the process of acquiring sport-specific motor skills in prepubertal soccer players. When considering the long-term training process, especially during childhood and before puberty, a wide range of FMS activities should be applied for better and possibly faster acquisition of soccer-specific motor skills.
- Publikační typ
- časopisecké články MeSH
Background: Normal weight obesity in children has been associated with excessive body fat, lower bone density and decreased total lean mass. However, no studies have been done into whether normal weight obese children differ in skeletal robustness or lean mass development on the extremities from normal weight non-obese, overweight, and obese peers although these are important indicators of healthy development of children. Methods: Body height, body weight, BMI, four skinfolds, and two limb circumferences were assessed. We calculated total body fat using Slaughter's equations, the Frame index for skeletal robustness and muscle area for the upper arm and calf using Rolland-Cachera equations. Using national references of BMI and measured skinfolds, three subgroups of participants (9-12 years) consisting of 210 middle-school-aged children (M-age = 11.01 ± 1.05)-110 girls and 100 boys-were selected: (A) overweight obese (OWOB) (n = 72); (B) normal weight obese (NWO) (n = 69); and, (C) normal weight non-obese (NWNO) (n = 69). All values, were converted to Z-scores to take account of participant's sex and age. Results: NWO children had significantly poorer skeletal robustness on lower extremities and poorer muscle area on the upper arm and calf compared to NWNO counterparts with significantly higher evidence in boys-skeletal robustness NWO boys: Z-score = -0.85; NWO girls: Z-score = -0.43; lean mass on the calf: NWO boys Z-score = -1.34; NWO girls: Z-score = -0.85. The highest skeletal robustness-but not muscle area on the calf-was detected in OWOB children. Conclusions: Further research should focus on whether this poor skeletal and lean mass development: (1) is a consequence of insufficient physical activity regimes; (2) affects physical fitness of NWO children and could contribute to a higher prevalence of health problems in them. We have highlighted the importance of the development of a simple identification of NWO children to be used by pediatricians.
- Publikační typ
- časopisecké články MeSH
- Publikační typ
- abstrakt z konference MeSH
Background: The Movement Assessment Battery for Children-second edition (MABC-2) Age Band 1 is widely used to identify preschoolers with motor difficulties. Despite unsatisfactory construct validity of the original three-factor model, MABC-2 (manual dexterity, aiming and catching, and balance), previous research has not considered possible age and gender differences throughout the entire preschool period. Aim: The aim of this study was to verify the construct validity of the MABC-2 Age Band 1 in a population of Czech preschoolers with respect to age and gender. Methods: Using data from 510 Czech preschoolers (3-6 years; 4.9 ± 1.1 years), confirmatory factor analyses (CFA) were used for each age category and gender. Results: The goodness-of-fit indices of CFA supported the original three-factor model of the MABC-2 only in 3- and 4-year-old children, and in boys (3-6 years). Low factor loadings and ceiling effects of several test items (Drawing Trail, Walking Heels Raised, and Jumping on Mats) seem to be a probable cause of weak fit indices in 5- and 6-year-old children and in girls (3-6 years). Conclusion: These results suggest that the MABC-2 can be a valid tool for assessing motor development and identifying motor difficulties among 3- to 4-year olds, and generally fits better for preschool boys in the Czech Republic. However, in 5- to 6-year olds, ceiling effects and a low power of discrimination was found for the Drawing Trail, Walking Heels Raised, and Jumping on Mats tests. Therefore, the three-factor model is not appropriate for all preschoolers, and separate norms should be established for each age and gender.
- Publikační typ
- časopisecké články MeSH
