Relationship between Stroking Parameters and Leg Movement Quantity in 100 Metre Front

The objective of this study was to examine the relationship between stroking technique parameters and leg kick quantity in 100 m front crawl swim. Ten New South Wales Sydney Metropolitan swimmers were examined (14.1 ± 1.09 years). The investigation was performed during 100 metre swimming (average speed 1.35 ± .04 [m.s-1]) commencing from water at 50 m outdoor pool. Stroke length (SL), Stroke rate (SR), Swim velocity (SV), Leg Kick Quantity (LKQ) were measured. Arm stroking parameters and LKQ were analysed during segment of the 100m distance. The relationship between SR and LKQ was negative. The correlation between stroke length and leg kick quantity was statistically significant r = .96, and p = .05. Leg Kick quantity influenced stroke length

Studies on soil animals in a remote region of Amazonia : particularly in relation to population assessment using field extractors.

This study was undertaken whilst leading expeditions to the Amazon in 1978 and I981. Laboratory and field methods of extracting invertebrates in soil are reviewed so as to highlight the problems inherent in collecting soil animals in remote regions. The main problem is to find an efficient, portable extraction unit that will provide reliable population estimates suitable to the environment under study. Following a detailed analysis of available literature it was decided to test a chemical extraction unit using turpentine as a repellent. This was a modification of Lewis’s extraction unit (1970) which was successfully used to repel thrips from flower heads. A trial comparison of the chemical extractor with a dry Tullgren technique using soil samples from temperate oak woodland showed that there was insufficient difference between the results to demonstrate the unsuitability of either technique. However, when the two techniques were compared with soil samples from tropical rain forest in Amazonia, the dry Tullgren funnel collected more species than the chemical unit. Further, the dry Tullgren funnel results suggested a much higher and more realistic soil animal population estimate than the chemical extractor which in turn was more efficient than a hand-sorting technique. The literature on tropical soil animal studies is reviewed. A comparative study of the soil animals living in a cultivated field and tropical rain forest soil was undertaken using a chemical extractor. The inefficiency of this type of extractor renders the results inconclusive. The evidence does however suggest that the efficiency of the chemical extractor improved when repelling animals from the drier soil collected at the cultivated field. Though the Tullgren funnel was more efficient in isolating organisms and the number of species was greater, the chemical extraction unit was a simpler method and still produced a number of different species so could be a useful and more easily managed tool for taxonomic investigations in remote areas. A limited number of soil cores collected two days after burning a cleared rain forest site demonstrated that the site still contained soil animals albeit in greatly reduced numbers. A modification of a type of corer used by Fletcher (1976) is described. This proved to be easily portable yet robust

Examining the link between isokinetic strength metrics and ball speed in women’s soccer

The shot performance of female soccer players is one of the most critical factors in winning a soccer match. It is essential to thoroughly clarify the kinetic factors that can improve shot performance. This study explores the connections between ball velocity post-shooting and isokinetic knee extension (EXT) and flexion (FLX) strength performances among female soccer players. Thirteen voluntary players from professional leagues took part in the research study. The study analyzed the average and peak concentric (Con) and eccentric (Ecc) torques, isometric (Iso) strength performances at angular velocities of 60 /s, 180 /s and 300 /s, the time required to reach peak torque, and ball velocities during shooting. The relationships among these variables were investigated separately for the dominant (D) and non-dominant (ND) legs. The analysis unveiled significant correlations between ball velocities and D-EXT (Absolute) peak torque at an angular velocity of 60 /s (r = 0.597; p < 0.05), D-%IPS (r = -0.580; p < 0.05), and ND-FLX (Absolute) average torque (r = 0.559; p < 0.05). Moreover, notable associations were observed between ball velocities and ND-EXT (Absolute) (r = 0.581; p < 0.05), as well as ND-FLX (Absolute) (r = 0.602; p < 0.05) average torques at an angular velocity of 180 /s. Additionally, significant relationships were found between ball velocities and peak (r = 0.664; p = 0.013) and average (r = 0.660; p = 0.014) torques generated during ND-EXT (Absolute) at an angular velocity of 300 /s. However, the connections between the time to reach peak torque, eccentric and isometric forces, and ball velocities were not statistically significant (p > 0.05). The results of the study indicate that enhancing concentric isokinetic strength development at 60 /s, 180 /s, and 300 /s angular velocities, along with balanced strengthening of the ND extremity, holds paramount importance in elevating shot performance among female soccer players, particularly in the context of rapid shot strategies.info:eu-repo/semantics/publishedVersio

Comparison between traditional and reverse periodization: swimming performance and specific strength values

International Journal of Swimming Kinetics 2(1): 87-96, 2013. Periodization of athletic training is conceptualized as a pedagogical process, which involves varying volume, intensity and frequency of training in attempt to optimize sporting performance. The primary purpose of this research was to compare changes in 100m swim performance (t100c), specific swim power output (SSP) and maximum drag charge (MDC), after 14 weeks of training traditional periodization (control) and reverse periodization (treatment). There were 26 volunteer swimmers (16.02±0.6 yrs. 1.72±9.3 cm 64.1±9.3 kg) divided in two groups traditional periodization (TP) and reverse periodization (RP). Results at the 14th week showed significant improvements (p\u3c0.05) in values of t100c (6.9%), SSP (20.9%) and MDC (10.0%) by RP above TP values. The results demonstrated that reverse periodization is specific and an efficient strategy of training for sprinters at time to reduce significantly load volume

Normative reference and cut-offs values of maximal aerobic speed-20 m shuttle run test and maximal oxygen uptake for Tunisian adolescent (elite) soccer players

This study aimed to develop reference curves of aerobic parameters of 20 m shuttle run test for Tunisian soccer players. The study was conducted in the 2022/2023 pre-season. The reference curves of the maximal aerobic speed (MAS) and the maximal oxygen uptake (VO2max) were developed according to the Lambda, Mu and Sigma (LMS) method, using data from 742 Tunisian premier league soccer players aged 11–18 years. Measured variables included: weight, height, body mass index and maximal heart rate (HRmax). HRmax was measured when the participants completed the maximal aerobic speed. VO2max was estimated using the 20 m shuttle run test protocol (speed increment every minute). Our results presented the smoothed percentiles (3rd, 10th, 25th, 50th, 75th, 90th and 97th) of MAS (km/h) and VO2max (ml/kg•min⁻1) according to age. In addition, raw data showed that VO2 max was positively correlated with age (r = 0.333; P < 0.001), height (cm) (r = 0.279; P < 0.001), weight (kg) (r = 0.266; P < 0.001), practice period (years) (r = 0.324; P < 0.001) and BMI (kg/m2) (r = 0.10; P < 0.05). However, it was negatively correlated to HRmax (bpm) (r = 0.247; P < 0.001). Only the measurements within the age group [12–12.99] are significantly higher (p < 0.001; ES = 0.63) compared with the previous age group [11–11.99]. Finally, regarding prevalence, our findings showed that 15.5 % of the players in our sample had VO2max values above the 87.7th percentile cut-off, while only 0.3 % exceeded the 99.18th percentile. The development of normative curves could help coaches and physical trainers to more accurately detect weaknesses in the aerobic performance of their players in order to sustain high-intensity repetitive actions during a soccer match.info:eu-repo/semantics/publishedVersio

Interventions to Promote the Development of Motor Performance Skills in Primary School Aged Children with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis of Controlled Trials

Background: The development of proficiency in motor performance skills (MPS) builds the foundation for the complex movement skills required to participate in a range of sports and physical activities throughout the lifespan. Objective: To assess the efficacy of different intervention approaches on developing MPS proficiency in children with autism spectrum disorder (ASD) and examine the intervention factors that influence change. Method: Searches were completed in three databases (PubMed/MEDLINE, Scopus, Web of Science) up to March 2022. Only randomised controlled trials (RCTs) or controlled trials (CTs), that evaluated the effectiveness of interventions on overall MPS proficiency or specific MPS such as balance, running speed and agility, bilateral coordination, jumping, ball skills and push-ups in children (4–13 years old) were included. The DerSimonian and Laird random-effects model was used to compute the meta-analyses. The effect sizes were reported as Hedges’ g. Using a random-effects model, potential sources of heterogeneity were identified, including subgroup analyses (type of intervention), and single training factor analysis (total number of weeks, session frequency, total intervention time, total number of training sessions). In addition, a multivariate meta-regression calculation was performed for balance. The GRADE framework was applied to assess certainty of evidence. Results: Seventeen interventions (13 RCTs and 4 CTs) revealed significant differences among groups favouring the intervention group with moderate to very large effects. Significant (p 0.05) small-to-large effects of interventions were evident on overall motor performance skills (ES = 2.43), ball skills (ES = 2.95), jumping (ES = 1.89), bilateral coordination (ES = 2.21), push-ups (ES = 1.92), balance (ES = 1.56), running speed and agility (ES = 1.31). Multivariate meta-regression for balance revealed that total sessions, total intervention time and session frequency predicted (p = 0.009, p0.001, p = 0.036, respectively) the effects of interventions on change in balance performance. Conclusion: Structured interventions that explicitly teach traditional FMS or promote the development and learning of movement skills specifically associated with a type of physical activity or sport, effectively improve MPS in children with ASD. Education settings should implement ‘planned’ movement experiences or interventions as a strategy to promote MPS proficiency in children with ASD

Making neuroscience a priority in Initial teacher education curricula: a call for bridging the gap between research and future practices in the classroom

Constant global advancements and expanding evidence in the neuroscience of learning have provided compelling support for the inclusion of neuroscience as a crucial content priority in initial teacher education. Existing research confirms the efficacy of neurocognitive interventions for atypical and typical school-aged learners in a variety of key subject areas. Despite advances in the neuroscience of learning, the adoption of contemporary approaches and strategies that support and enhance neurocognitive development by education practitioners is yet to be the norm. Incorporating neuroscience education content, research, and practical application into initial teacher education curricula will enhance teacher preparation, leading to evidence-based education.info:eu-repo/semantics/publishedVersio

Obesity status and physical fitness levels in male and female portuguese adolescents: a two-way multivariate analysis

Obesity and decreasing fitness levels among the youth are growing concerns in Portugal, similar to other developed countries, with implications for health and psychomotor development. Understanding the influence of health determinants such as sex and age are crucial for developing effective public health strategies. This study aimed to analyze the association between sex and chronological age with obesity status and physical fitness in Portuguese adolescents. A total of 170 adolescents (85 males and 85 females) were evaluated for body mass index, abdominal adiposity, aerobic fitness, abdominal resistance, upper limb resistance, lower limb power, and maximal running speed in a 40 m sprint using the FITescola® physical fitness battery, a Portuguese government initiative. The general model, analyzed using Pillai’s trace, showed a significant effect of age and sex on body mass index, abdominal circumference, aerobic fitness, abdominal resistance, upper limb resistance, lower limb power, and maximal running speed (V = 0.99, F (7) = 10,916.4, p < 0.001, partial η2, sex = 0.22; age = 0.43, sex and age interaction = 0.10). Boys had higher physical fitness levels than girls in most tests, but both sex groups had a significantly higher proportion of non-fit adolescents, with boys showing the highest number of participants classified as non-fit.This research was funded by the National Funds through FCT—Portuguese Foundation for Science and Technology (UIDB/DTP/04045/2020).info:eu-repo/semantics/publishedVersio

A Deep Learning Neural Network to Classify Obesity Risk in Portuguese Adolescents Based on Physical Fitness Levels and Body Mass Index Percentiles: Insights for National Health Policies

The increasing prevalence of overweight and obesity among adults is a risk factor for many chronic diseases and death. In addition, obesity among children and adolescents has reached unprecedented levels and studies show that obese children and adolescents are more likely to become obese adults. Therefore, both the prevention and treatment of obesity in adolescents are critical. This study aimed to develop an artificial intelligence (AI) neural network (NNET) model that identifies the risk of obesity in Portuguese adolescents based on their body mass index (BMI) percentiles and levels of physical fitness. Using datasets from the FITescola® project, 654 adolescents aged between 10–19 years old, male: 334 (51%), female: n = 320 (49%), age 13.8 ± 2 years old, were selected to participate in a cross-sectional observational study. Physical fitness variables, age, and sex were used to identify the risk of obesity. The NNET had good accuracy (75%) and performance validation through the Receiver Operating Characteristic using the Area Under the Curve (ROC AUC = 64%) in identifying the risk of obesity in Portuguese adolescents based on the BMI percentiles. Correlations of moderate effect size were perceived for aerobic fitness (AF), upper limbs strength (ULS), and sprint time (ST), showing that some physical fitness variables contributed to the obesity risk of the adolescents. Our NNET presented a good accuracy (75%) and was validated with the K-Folds Cross-Validation (K-Folds CV) with good accuracy (71%) and ROC AUC (66%). According to the NNET, there was an increased risk of obesity linked to low physical fitness in Portuguese teenagers.This project was supported by the National Funds through the FCT—Portuguese Foundation for Science and Technology (project UIDB/04045/2021).info:eu-repo/semantics/publishedVersio