ABSTRACT
It is vital from the public health and educational perspective to be familiar with changes in the fitness levels of individuals and populations since fitness is associated with several health outcomes and cognition. Skill-related physical fitness refers to performance in sports or occupation and is associated with motor skill performance. The aim of the present study was to examine secular trends in skill-related physical fitness of 16 678 participants in four youth generations of Slovenian children and adolescents in years 1983 (n = 3128), 1993/94 (n = 3413), 2003/04 (n = 5497), and 2013/14 (n = 4640). Using repeated cross-sectional design, we observed fitness level of all participants divided into three age groups: 6-10, 11-14, and 15-19 years. Skill-related physical performance was measured with seven fitness tests for speed, coordination, balance, and flexibility. Analysis of covariance was used to compare differences in fitness performance between decades in each age and sex group, adjusted for body height, body weight, and body mass index. Overall, large but inconsistent changes in coordination, a small improvement in speed, and a decline in flexibility were seen. The trends over the whole examined period were not linear throughout decades. Generally, positive trends were noticed in periods 1983-1993 (range 1.4%-17.9%; except flexibility) and 2003/04-2013/14 (range 0.2%-36.4%; except age group 15-19 years) while in the period 1993/94-2003/04 there are some particularities in secular trends according to individual components as well as age groups. In general, the secular trend showed a positive direction for both genders (p < 0.05), except for gross motor coordination, which demonstrated positive trends in 1993 and 2013 compared with a decade earlier (p < 0.05) and from 1983 to 2013/14, except for the youngest boys in 2003 and the youngest girls from 1993 to 2003 (p < 0.05). Our findings call for exercise programs aimed at improving speed and gross motor coordination in both sexes and all age groups, especially in the group of 15-19 years old.
ABSTRACT
OBJECTIVES: (1) To develop reference values for health-related fitness in European children and adolescents aged 6-18 years that are the foundation for the web-based, open-access and multilanguage fitness platform (FitBack); (2) to provide comparisons across European countries. METHODS: This study builds on a previous large fitness reference study in European youth by (1) widening the age demographic, (2) identifying the most recent and representative country-level data and (3) including national data from existing fitness surveillance and monitoring systems. We used the Assessing Levels of PHysical Activity and fitness at population level (ALPHA) test battery as it comprises tests with the highest test-retest reliability, criterion/construct validity and health-related predictive validity: the 20 m shuttle run (cardiorespiratory fitness); handgrip strength and standing long jump (muscular strength); and body height, body mass, body mass index and waist circumference (anthropometry). Percentile values were obtained using the generalised additive models for location, scale and shape method. RESULTS: A total of 7 966 693 test results from 34 countries (106 datasets) were used to develop sex-specific and age-specific percentile values. In addition, country-level rankings based on mean percentiles are provided for each fitness test, as well as an overall fitness ranking. Finally, an interactive fitness platform, including individual and group reporting and European fitness maps, is provided and freely available online (www.fitbackeurope.eu). CONCLUSION: This study discusses the major implications of fitness assessment in youth from health, educational and sport perspectives, and how the FitBack reference values and interactive web-based platform contribute to it. Fitness testing can be conducted in school and/or sport settings, and the interpreted results be integrated in the healthcare systems across Europe.
Subject(s)
Hand Strength , Physical Fitness , Male , Female , Humans , Adolescent , Child , Reference Values , Reproducibility of Results , Exercise , Exercise Test/methods , Body Mass IndexABSTRACT
ABSTRACT: Blagus, R, Jurak, G, Starc, G, and Leskosek, B. Centile reference curves of the SLOfit physical fitness tests for school-aged children and adolescents. J Strength Cond Res 37(2): 328-336, 2023-The study provides sex- and age-specific centile norms of Slovenian children and youth. Physical fitness was assessed using the SLOfit test battery on population data, including 185,222 children, aged 6-19 years, measured in April and May 2018. Centile curves for both sexes and 12 test items were constructed using the generalized additive models for location, scale, and shape (GAMLSS). Boys generally achieved higher scores in most of the physical fitness tests, except in stand and reach, but this was not consistent throughout childhood and adolescence, nor did it pertain to the entire range of performance. Girls outperformed boys in the arm-plate tapping test throughout childhood; the poorest performing girls outperformed the poorest performing boys in the 600-m run, 60-m dash, backward obstacle course, and standing broad jump. The shapes and trends of physical fitness curves adequately reflect the effects of growth and development on boys' and girls' physical performance. Comparing the existing reference fitness curves showed that Slovenian children and adolescents display higher fitness levels than their peers from other countries. This study provides the most up-to-date sex- and age-specific reference fitness centile curves of Slovenian children, which can be used as benchmark values for health and fitness monitoring and surveillance systems.
Subject(s)
Exercise , Physical Fitness , Male , Female , Humans , Adolescent , Child , Exercise Test , Reference ValuesABSTRACT
BACKGROUND: It is unclear whether active commuting has the potential to improve children's health. This study examined the association of commuting mode and distance with children's cardiorespiratory fitness (CRF). METHODS: We conducted a cross-sectional study, including 713 Slovenian schoolchildren aged 12 to 15 years. Commuting modes were self-reported, and four commuting groups were constructed, while CRF was determined with a 20-m shuttle run test. The distance from home to school was calculated using the Geographic Information System. Effects of commuting mode and distance, controlling for age, gender and amount of total physical activity, were evaluated using general two linear models (one for each direction of commuting to/from school). RESULTS: The main effect of commuting group on CRF and its interaction with distance were significant in the direction from school to home (P = 0.013 and P = 0.028, respectively), but not in the opposite direction. Predicted differences in CRF between commuting groups were moderate and generally higher in males than in females. When comparing commuting group median distance from home to school, males driven by car had around 4 ml/min/kg lower predicted CRF than those who walked (P = 0.01) or used wheels commuting (e.g., bicycle, skateboard). CONCLUSIONS: The distance of commuting had a small effect on CRF, except in the Car group where children who live close to school had significantly lower CRF than those living further away. Children driven by car who live within wheels or walk distance from school should be targeted by interventions promoting active transport.
Subject(s)
Cardiorespiratory Fitness , Adolescent , Bicycling , Child , Cross-Sectional Studies , Female , Humans , Male , Schools , Transportation , WalkingABSTRACT
The aim of this study was to find a trend of changes for selected anthropometric characteristics and motor abilities of young male and female tennis players of three different age groups. Trends were observed in the periods between 1992, 2000 and 2008. In addition, a comparison of results of tennis players and school pupils was included. The sample of subjects were selections of young tennis players and of primary and secondary schools pupils (boys and girls) divided into three age groups (12- to 13-year-olds, 14- to 15-year-olds, and 16- to 17-year-olds). Fitness tests items (backwards obstacle course, forward bend on the bench, 20-second hand-tapping, 60-second sit-ups) and three anthropometric measurements (body height, body weight, BMI) were included in this study. The analysis of trends for different periods of measurement in male and female tennis players revealed an increase in some test items and a decrease in others. In the majority of observed fitness test items, young tennis players performed better than their school peers, indicating the positive effects of training and an appropriate selection process of tennis players. Male and female tennis players were taller than the school pupils, and body height values in both groups increased from 1992 to 2008. The body weight and BMI values for male and female tennis players, and male and female pupils in all three age groups have been constantly increasing.
Subject(s)
Athletes , Physical Fitness , Tennis , Adolescent , Anthropometry , Body Height , Body Mass Index , Body Weight , Child , Female , Humans , Male , Multivariate AnalysisABSTRACT
BACKGROUND: We evaluated accuracy of urinary liver type fatty acid-binding protein (L-FABP) for prediction of early allograft function and compared it to neutrophil gelatinase associated lipocalin (NGAL), diuresis and urinary creatinine excretion rate (UCr). METHODS: Urine samples from 71 consecutive patients were taken 4, 10, 24 and 48 h after transplantation. We classified recipients into two groups: immediate graft function (IGF), with more than 70% reduction of serum Cr at 7th day post-transplant, and delayed graft function (DGF)/slow graft function (SGF) group (DGF--the need for hemodialysis procedure in the first week, SGF--less than 70% reduction of serum Cr in the first week). RESULTS: Thirty-one recipients had IGF and 40 had DGF/SGF. L-FABP was only useful 48 h post-transplant with ROC AUC of 0.85 (95% C.I. 0.74-0.92); NGAL 24 h post-transplant had ROC AUC of 0.82 (0.7-0.91). Sensitivity, specificity, PPV and NPV for prediction of DGF/SGF with L-FABP > 9.5 mg/mmol Cr and NGAL > 33.1 µg/mmol Cr were: 86, 80, 83 and 83% (L-FABP), and 68, 93, 91, and 73% (NGAL). The difference in urine output between the groups was largest 4 h post-transplant (p = 0.001), later on the difference diminished. There were no significant differences in ROC AUC between L-FABP at 48 h, NGAL at 24 h, urine output at 4 h and UCr excretion rate at 10 h post-transplant. UCr < 0.56 mmol/h 10 h post-transplant predicted DGF/SGF with 94% sensitivity, 84% specificity, 89% PPV and 91% NPV, ROC AUC was 0.9. Classification tree with urine output 4 h and UCr 10 h post-transplant accurately predicted 89% of outcomes. When L-FABP or NGAL were added, the prediction was accurate in 92 or 90%, respectively. CONCLUSIONS: L-FABP is comparable to NGAL for prediction of first week allograft function, however UCr and diuresis were non-inferior.
Subject(s)
Acute-Phase Proteins/urine , Allografts/metabolism , Creatinine/urine , Fatty Acid-Binding Proteins/urine , Graft Survival/physiology , Kidney Transplantation/trends , Lipocalins/urine , Proto-Oncogene Proteins/urine , Adult , Biomarkers/urine , Female , Humans , Kidney Transplantation/adverse effects , Lipocalin-2 , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Time FactorsABSTRACT
During the course of their work, teachers may be subjected to conditions that cause different health problems. This study examines occupational health disorders in a representative sample of 858 teachers (528 female; age 44.0 ± 9.67 years) divided into three groups of teachers with specific occupational requirements: specialist physical education teachers (specialist PETs), classroom teachers, and specialist teachers. The number of health disorders in the last 12 months was recorded using the Chronic Health Disorders Questionnaire. The differences between the different types of teachers, controlled for sex and age, were analyzed using binary logistic regression. The results showed that 89% of teachers experienced colds as the most frequently reported health problem, followed by 58% for lower back problems, 57% for headaches, 51% for hoarseness, and 43% for neck problems. A binary logistic regression showed that specialist PETs were the group with the highest health risk. They were about twice as likely to have musculoskeletal or hearing disorders than the other two groups of teachers. They were also significantly more likely to suffer from hoarseness. Understanding these different health challenges is critical to developing targeted interventions and robust support systems. These interventions should include initiatives aimed at raising awareness of health risk factors, implementing injury interventions and vocal cord hygiene programs, making ergonomic adjustments, and promoting awareness of self-care (both mental and physical). Given that the teaching profession is currently struggling with an aging workforce and a shortage of teachers, addressing these challenges is critical to the continued well-being of the teaching professionals.
Subject(s)
Occupational Diseases , Physical Education and Training , School Teachers , Humans , Female , Male , Adult , Middle Aged , School Teachers/statistics & numerical data , Physical Education and Training/statistics & numerical data , Occupational Diseases/epidemiology , Surveys and Questionnaires , Logistic Models , Occupational Health/statistics & numerical dataABSTRACT
Many school-based physical activity (PA) interventions have been developed, but only a few have assessed their long-term effects. A PA intervention taking place in the first four years of some Slovenian primary schools entails an enhanced physical education (PE) curriculum, including two extra lessons of PE per week, a wider selection of PE content, and additional outdoor education delivered by both a specialist PE teacher and a general teacher. The effects of the intervention on children's physical fitness (motor tasks and anthropometry) were evaluated within a quasi-experimental study. In total, 324 children from nine Slovenian primary schools either received the enhanced curriculum (intervention (n=160)) or standard PE (control (n=164)), and were followed for a four-year intervention period and seven years post intervention. Data from the SLOFIT database were used to compare differences in the physical fitness of children each year. Linear Mixed Models were used to test the influence of the PA intervention. Over an 11-year period, the PA intervention group significantly differed in all motor tasks, but not in anthropometric measures or body mass index, after controlling for year of measurement and sex. Differences between the control and intervention groups decreased with time. This study highlights the importance of tracking the long term effects of PA interventions. PA intervention in the first four years of Slovenian primary school offers the possibility of improving physical performance in children; initiatives aiming to increase their performance (physical fitness, physical activity) and health outcomes are warranted.
Subject(s)
Body Weights and Measures , Exercise , Physical Education and Training/statistics & numerical data , Physical Fitness , Schools/statistics & numerical data , Adolescent , Child , Female , Health Promotion , Humans , Longitudinal Studies , Male , Motor SkillsABSTRACT
A cross-sectional study was carried out to examine the frequency and types of serious injuries in physical educators throughout their professional career, in relation to their gender, age and teaching level, certain factors causing the injuries and the consequences of those injuries on their working ability. The subjects (n = 468) answered a self-administered questionnaire. In men, one group's higher frequency of injuries was 1.8 (95% CI [1.26, 2.57]) times higher than in women. Every year in age increased the odds for moving into a group with a higher frequency of injuries by 7.6% (95% CI [1.06, 1.10]). The most common injuries for both genders were lower limb injuries. The most common cause of injury was the teacher's own mistake. Over 60% of teachers had to modify their teaching after an injury. It is necessary to further explore preventive strategies to reduce injuries in these workers.
Subject(s)
Physical Education and Training/statistics & numerical data , Teaching/statistics & numerical data , Wounds and Injuries/epidemiology , Adult , Age Factors , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Slovenia/epidemiologyABSTRACT
Understanding the growth pattern is important in view of child and adolescent development. Due to different tempo of growth and timing of adolescent growth spurt, individuals reach their adult height at different ages. Accurate models to assess the growth involve intrusive radiological methods whereas the predictive models based solely on height data are typically limited to percentiles and therefore rather inaccurate, especially during the onset of puberty. There is a need for more accurate non-invasive methods for height prediction that are easily applicable in the fields of sports and physical education, as well as in endocrinology. We developed a novel method, called Growth Curve Comparison (GCC), for height prediction, based on a large cohort of > 16,000 Slovenian schoolchildren followed yearly from ages 8 to 18. We compared the GCC method to the percentile method, linear regressor, decision tree regressor, and extreme gradient boosting. The GCC method outperformed the predictions of other methods over the entire age span both in boys and girls. The method was incorporated into a publicly available web application. We anticipate our method to be applicable also to other models predicting developmental outcomes of children and adolescents, such as for comparison of any developmental curves of anthropometric as well as fitness data. It can serve as a useful tool for assessment, planning, implementation, and monitoring of somatic and motor development of children and youth.
Subject(s)
Puberty , Sports , Male , Child , Adolescent , Female , Humans , Adult , Anthropometry , Age Determination by Skeleton/methods , Cell Proliferation , Body Height , GrowthABSTRACT
Using the population-based data we aim to estimate the general population trends of multiple components of physical fitness of children, identify critical structural changes in these trends, and evaluate the potential changes in differences in the test scores between the children. During the entire study period, 1989-2019, median body mass index and triceps skinfold increased in both genders and all age groups. Muscular fitness, in general, showed negative trends, with some exceptions: during the post-2010 period, children were mostly experiencing the improvement of isometric strength of the upper body. The neuromuscular components of physical fitness showed positive trends, especially in girls. Cardiorespiratory fitness has been declining in all age groups until the last decade, with the largest decreases occurring before 2000. In the last decade, the trends reversed. The flexibility indicator revealed the largest differences between boys and girls, with boys mainly experiencing negative and girls mostly positive trends. The variability of the test scores mostly increased during the study period. This increasing variance suggests that-despite generally favourable trends in the last decade-children in Slovenia have been facing increasing inequalities in their development, which can potentially lead to future inequalities in health.
Subject(s)
Cardiorespiratory Fitness , Physical Fitness , Body Mass Index , Exercise , Female , Humans , Male , SloveniaABSTRACT
SLOfit Lifelong is a public health initiative which was created to upgrade a well-established, national physical fitness surveillance system for Slovenian schoolchildren that has been collecting annual fitness and health data for over three decades. The ultimate objective of creating SLOfit Lifelong was to build a modern societal infrastructure with the capacity and ability to detect future causal associations between childhood physical fitness trends and future health outcomes based on the lifelong surveillance of one's own fitness status. By instilling citizens with an ambition to test, understand, and follow-up their own physical fitness and health status (including related health risk factors), this initiative provides the technical support and expert feedback needed to engender greater individual control over understanding (and thus modulating), one's own physical fitness status as they progress into older adulthood. This perspective paper details the extensive approach taken to devise appropriate fitness test batteries for adults and older adults which can also relate to the student version of the original SLOfit test database, including establishing criterion health risk zones and a public approach to establish this national, citizen-driven health feedback framework. Through its sophisticated online web applications, social media, print media, and outreach workshops, SLOfit Lifelong provides the expert support for public health engagement by fostering positive lifelong physical literacy experiences an individual can enjoy across their aging journey.
Subject(s)
Citizen Science , Aged , Child , Exercise , Humans , Literacy , Longevity , Physical FitnessABSTRACT
To date, few data on how the COVID-19 pandemic and restrictions affected children's physical activity in Europe have been published. This study examined the prevalence and correlates of physical activity and screen time from a large sample of European children during the COVID-19 pandemic to inform strategies and provide adequate mitigation measures. An online survey was conducted using convenience sampling from 15 May to 22 June, 2020. Parents were eligible if they resided in one of the survey countries and their children aged 6-18 years. 8395 children were included (median age [IQR], 13 [10-15] years; 47% boys; 57.6% urban residents; 15.5% in self-isolation). Approximately two-thirds followed structured routines (66.4% [95%CI, 65.4-67.4]), and more than half were active during online P.E. (56.6% [95%CI, 55.5-57.6]). 19.0% (95%CI, 18.2-19.9) met the WHO Global physical activity recommendation. Total screen time in excess of 2 h/day was highly prevalent (weekdays: 69.5% [95%CI, 68.5-70.5]; weekend: 63.8% [95%CI, 62.7-64.8]). Playing outdoors more than 2 h/day, following a daily routine and being active in online P.E. increased the odds of healthy levels of physical activity and screen time, particularly in mildly affected countries. In severely affected countries, online P.E. contributed most to meet screen time recommendation, whereas outdoor play was most important for adequate physical activity. Promoting safe and responsible outdoor activities, safeguarding P.E. lessons during distance learning and setting pre-planned, consistent daily routines are important in helping children maintain healthy active lifestyle in pandemic situation. These factors should be prioritised by policymakers, schools and parents. HighlightsTo our knowledge, our data provide the first multi-national estimates on physical activity and total screen time in European children roughly two months after COVID-19 was declared a global pandemic.Only 1 in 5 children met the WHO Global physical activity recommendations.Under pandemic conditions, parents should set pre-planned, consistent daily routines and integrate at least 2-hours outdoor activities into the daily schedule, preferable on each day. Schools should make P.E. lessons a priority. Decision makers should mandate online P.E. be delivered by schools during distance learning. Closing outdoor facilities for PA should be considered only as the last resort during lockdowns.
Subject(s)
COVID-19 , Screen Time , Adolescent , COVID-19/epidemiology , COVID-19/prevention & control , Child , Communicable Disease Control , Exercise , Female , Humans , Male , Pandemics , SchoolsABSTRACT
OBJECTIVES: Determine the temporal trends in cardiorespiratory fitness (CRF) and health risk of Slovenian schoolchildren across a 20-year span, assessed via 20-m shuttle run (20mSRT), including defining centile ranges and possible health risk(s) for each generation. METHODS: Nationally representative data from 9,426 healthy schoolchildren (6-14 years old) were used to determine changes in CRF across three generations, in 1993 (n = 3,174), 2003 (n = 3,457) and 2013 (n = 2,795) from a multistage, stratified, decennial study. RESULTS: 20mSRT performance declined â¼2.8% from 1993 to 2003, independent of age or sex of the child. This trend was reversed in 2013, increasing by â¼8.2% across all age groups, for both girls and boys, for a net increase of 5.4%. The magnitude of improvement was similar for both sexes. Moreover, girls in the 2013 generation (for ages 10-13 year) completed more stages than their 2003 male counterparts. Across all generations, children achieved CRF values corresponding to low cardiovascular risk for future health outcomes. Centile values ranged from "low" to "very high" depending on age, sex, and generation of the sample. CONCLUSION: Negative trends in CRF from Slovenian schoolchildren were reversed by 2013, indicating that Slovenia should continue implementing progressive national physical fitness strategies introduced between sampling periods (i.e., 2003-2013). Additionally, due to the universal nature of Slovenian schoolchildren achieving "healthy cut-off values" for 20mSRT (generation-inclusive), it is suggested that more specific cut-off criteria are developed, especially for younger children, and girls, so that future CRF results can be more accurately applied for both clinical and pedagogical users.
ABSTRACT
The Republic of Slovenia implements the largest longitudinal database of child physical fitness in the world-SLOfit. Slovenia has some of the most physically active children globally, and it has responded rapidly to incorporate national physical activity (PA) interventions throughout the COVID-19 pandemic. Despite aggressive campaigns to maintain PA at home, the country has seen a tremendous decrease in child physical fitness over the past several months as self-isolation measures have been mandated by national authorities. These trends prompted researchers to create a method of tracking and communicating government decisions which have a direct impact on child physical activity, fitness and overall health (i.e., the SLOfit Barometer). The research team assembled experts for consultation on creation of the SLOfit Barometer after processing preliminary data on 20,000 schoolchildren which found the greatest decline in child physical fitness since systematic testing began more than 30 years ago. Only 2 months of self-isolation erased over 10 years of hard-fought health gains acquired from national public health policies and PA interventions. This crisis in child fitness requires integrated community participation and a robust public health policy response, and with the SLOfit Barometer acting as a national bellwether system, it is envisioned that policy makers and the public will advocate for bold, progressive actions to combat this national health emergency. This surveillance tool tracks government action to combat the increasing child physical inactivity and obesity trends brought on as a direct result of COVID-19 isolation regulations.
Subject(s)
COVID-19/psychology , Health Promotion , Physical Fitness/physiology , Public Health , Quarantine , Surveys and Questionnaires/statistics & numerical data , Adolescent , Child , Child, Preschool , Humans , SloveniaABSTRACT
The proportion of overweight children and adults has been growing rapidly in the last few years in many European and other countries. Certain consequences of overweight are already manifested in youth; in adulthood they are one of the main causes of death and several diseases. The study examined the proportion of overweight and obese Slovenian girls aged 7 to 18 with the use of an annually repeated cross-sectional study. The study lasted from 1991 to 2006 and was based on the body mass index according to IOTF norms. The results show that in this period the proportion of overweight girls increased by almost 30% (from 13.5% to 18.8%), whereas the proportion of obese girls doubled (from 2.3% to 4.6%). The prevalence of overweight and obesity is highest in childhood and early adolescence where it is around two to three times higher than at the age of 18.
Subject(s)
Obesity/epidemiology , Overweight/epidemiology , Adolescent , Child , Cross-Sectional Studies , Female , Humans , Prevalence , Slovenia/epidemiology , Students , Time FactorsABSTRACT
PURPOSE: The aim of this study was to assess the reliability and validity of the new judging system in DanceSport. METHODS: Eighteen judges rated the 12 best placed adult dancing couples competing at an international competition. They marked each couple on all judging criteria on a 10 level scale. Absolute agreement and consistency of judging were calculated for all main judging criteria and sub-criteria. RESULTS: A mean correlation of overall judging marks was 0.48. Kendall's coefficient of concordance for overall marks (W = 0.58) suggesting relatively low agreement among judges. Slightly lower coefficients were found for the artistic part [Partnering skills (W = 0.45) and Choreography and performance (W = 0.49)] compared to the technical part [Technical qualities (W = 0.56) and Movement to music (W = 0.54)]. ICC for overall criteria was low for absolute agreement [ICC(2,3) = 0.62] but higher for consistency [ICC(3,3) = 0.80]. CONCLUSION: The relatively large differences between judges' marks suggest that judges either disagreed to some extent on the quality of the dancing or used the judging scale in different ways. The biggest concern was standard error of measurement (SEM) which was often larger than the difference between dancers scores suggesting that this judging system lacks validity. This was the first research to assess judging in DanceSport and offers suggestions to potentially improve both its objectivity and validity in the future.
ABSTRACT
Physical fitness is important in view of reducing risks for a number of non-communicable diseases, both for individuals and policy-makers. In this paper, we present a prototype tool that combines forecasting of individual fitness parameters of schoolchildren to early adulthood with estimation of relative risk for all-cause early mortality in adulthood based on the forecasted fitness. This tool is a first step in the development of a platform that will show age, gender, and geographical distributions of risk and suggest potential interventions.
Subject(s)
Exercise , Mortality , Physical Fitness , Risk Assessment , Adult , Child , Child Health , Forecasting , Humans , RiskABSTRACT
The purpose of the study was to determine the timing of a split-step in three categories of tennis players in four groups of strokes. Subjects were divided into three groups: male and female junior, and male professional tennis players. During two tournaments, all matches were recorded with two fixed video cameras. For every stroke, the timing of the split-step between the opponent's impact point when hitting the ball and the player's split-step was measured. A two-way analysis of variance (ANOVA) was used to determine the differences between groups of strokes, players and the interaction Player x Stroke Group. A Tukey post-hoc test was employed to determine specific differences. The results revealed differences between players in detecting the opponent's movement, stroke and ball flight, which were reflected in different split-step timings. Each tennis player has his/her own timing mechanism which they adapt to various game situations. Response times differ significantly depending on the game situation. On average, they are the lowest in the serve, and then gradually rise from the return of the serve to baseline game, reaching the highest values in specific game situations. Players react faster in the first serve than in the second one and in the return of the serve, the response times are lower after the return of the second serve.
ABSTRACT
This study investigated tennis players' speed before, during and after the split-step, deceleration before and acceleration after the split-step in four different stroke groups in three age categories. Seven male professional, eleven male and ten female junior tennis players were recorded with video cameras at official tournaments. Using the SAGIT system, we gathered data on 8,545 split-steps. Tennis players performed a split-step in 82.9% of cases. A tennis player's speed, deceleration and acceleration were measured 0.2 s before and after the split-step. Differences between categories and stroke groups for each of the five variables were analyzed with a two-way ANOVA. The differences between the groups of players were generally much higher in the speed before, during and after the split-step than in the deceleration before and acceleration after the split-step. Most of these differences were observed between the various stroke groups. These results suggest that players use three types of movement while performing a split-step. In the first type, which is typical of serving and returning, the speed before, during and after the split-step is lower (0.55 to 1.2 m/s). The second type of movement is characteristic of baseline strokes where tennis players achieve higher speed than in the first type (0.7 to 1.66 m/s). The third type occurs in strokes where a tennis player is moving or already at the net (0.78 to 1.9 m/s). Movement in tennis is an area that requires constant development in terms of designing and upgrading movement patterns, increasing speed and practice in specific game situations.