Youth Fitness Research Articles

Skeletal muscle contributions to reduced fitness in cystic fibrosis youth.

Increased maximal oxygen uptake (V̇O2max) is beneficial in children with cystic fibrosis (CF) but remains lower compared to healthy peers. Intrinsic metabolic deficiencies within skeletal muscle (muscle "quality") and skeletal muscle size (muscle "quantity") are both proposed as potential causes for the lower V̇O2max, although exact mechanisms remain unknown. This study utilises gold-standard methodologies to control for the residual effects of muscle size from V̇O2max to address this "quality" vs. "quantity" debate. Fourteen children (7 CF vs. 7 age- and sex-matched controls) were recruited. Parameters of muscle size - muscle cross-sectional area (mCSA) and thigh muscle volume (TMV) were derived from magnetic resonance imaging, and V̇O2max obtained via cardiopulmonary exercise testing. Allometric scaling removed residual effects of muscle size, and independent samples t-tests and effect sizes (ES) identified differences between groups in V̇O2max, once mCSA and TMV were controlled for. V̇O2max was shown to be lower in the CF group, relative to controls, with large ES being identified when allometrically scaled to mCSA (ES = 1.76) and TMV (ES = 0.92). Reduced peak work rate was also identified in the CF group when allometrically controlled for mCSA (ES = 1.18) and TMV (ES = 0.45). A lower V̇O2max was still observed in children with CF after allometrically scaling for muscle size, suggesting reduced muscle "quality" in CF (as muscle "quantity" is fully controlled for). This observation likely reflects intrinsic metabolic defects within CF skeletal muscle.

Adherence to Recess Guidelines in the United States Using Nationally Representative Data: Implications for Future Surveillance Efforts.

National adherence to the recess recommendations of the Centers for Disease Control and Prevention (CDC) has not been comprehensively studied in the United States. Data from 6 nationally representative data sets over the last decade (Classification of Laws Associated with School Students, Early Childhood Longitudinal Study, National Health and Nutrition Examination Survey, National Youth Fitness Survey, School Health Policies and Practices Survey, and the School Nutrition and Meal Cost Study) provided estimates for adherence to CDC recess guidelines. While approximately 65-80% of elementary school-children receive the recommended 20+ minutes of daily recess according to parent-, principal-, and school-report, adherence declines by sixth grade, and little information is available for middle/high school students. Adherence to playground safety was high (90%), but adherence to recommendations about recess before lunch (<50%), withholding recess as punishment (∼50%), and training recess staff (<50%) were lower. School policy and practice should align with CDC recommendations, with the aim of providing sufficient quality recess to all youth, K-12th grade. Comprehensive, on-going national surveillance of multiple recess domains is needed to inform policy and ensure equitable provision of recess.

Cardiorespiratory fitness and BMI in youth and site-specific cancer mortality in men: A population-based cohort study with register linkage.

10534 Background: There is insufficient evidence on the associations between cardiorespiratory fitness (CRF), body mass index (BMI), and site-specific cancer mortality. Methods: We collected data on all men who underwent military conscription 1968-2005 in Sweden at ages 16-25. CRF was assessed as maximal aerobic workload on a cycle ergometer test and classified as low, moderate, or high. BMI (kg/m2) was classified as underweight ( &lt; 18.5), normal weight (18.5-24.9), overweight (25-29.9), or obesity (≥30). Data was cross-linked on individual level through the Swedish identification number with national registers with high validity for information on cancer mortality. Follow-up was from conscription until death, emigration, or end of follow-up (12/31/2019). Cox regression analyses included CRF and BMI as well as age, year, and site of conscription, parental education, and muscle strength. Primary analyses tested linear trends for CRF and BMI, with effect sizes for categorical comparisons for interpretation. Results: 1,083,738 men were included in the analyses and were followed for a mean of 33 years, during which 8,912 cancer-specific deaths occurred. Lower CRF and higher BMI were linearly associated with any cancer mortality as well as with several site-specific cancer mortalities (table). However, death in some major cancer sites (prostate, CNS) were not associated with CRF or BMI and higher CRF was associated with higher mortality from malignant skin cancer. Conclusions: Higher CRF and lower BMI was associated with lower cancer mortality for some, but not all cancer sites. These results could be used as a further incentive for working with modifiable risk factors in public health. [Table: see text]

Performance-related physiological changes induced by one year of endurance training in young athletes.

Although maximal oxygen uptake (VO2max) is generally recognized as the single best indicator of aerobic fitness in youth, interpretation of this parameter and the extent to which it can be improved by training remain controversial, as does the relative importance of VO2max for performance in comparison to other factors such as power production. Here, we examined the influence of endurance training on the VO2max, muscle power and sports-related performance of cross-country skiers attending a school specializing in sports, as well as potential relationships between any changes observed to one another and/or to perceived stress scale (Cohen) and certain blood parameters. On two separate occasions, prior to the competition season and separated by one year of endurance training, the 12 participants (5 males, 7 females, 17 ± 1 years) carried out tests for VO2max on a treadmill, explosive power utilizing countermovement jumps (CMJ) and ski-specific maximal double pole performance (DPP) employing roller skis on a treadmill. Blood levels of ferritin (Fer), vitamin D (VitD) and hemoglobin (Hg) were monitored, and stress assessed with a questionnaire. DPP improved by 10 ± 8% (P < 0.001), but no other significant changes were observed. There were no significant correlations between the changes in DPP and any other variable. Whereas one year of endurance training improved the cross-country ski-specific performance of young athletes significantly, the increase in their maximal oxygen uptake was minimal. Since DPP was not correlated with VO2max, jumping power or the levels of certain blood parameters, the improvement observed probably reflected better upper-body performance.

ПОВЫШЕНИЕ УРОВНЯ ФИЗИЧЕСКОЙ ПОДГОТОВЛЕННОСТИ СТУДЕНТОВ

The role of higher education in increasing the level of physical fitness of student youth, introducing them to physical exercises is considered. An increase in the level of physical fitness of the Angarsk State Technical University students from 50 to 85% was revealed in the process of their education at the university due to the study and consolidation in practice of the mechanisms of development of physical qualities

Association of Recess Provision With Elementary School-Aged Children's Physical Activity, Adiposity, and Cardiorespiratory and Muscular Fitness.

To identify associations between amount of school recess provision and children's physical activity (PA), weight status, adiposity, cardiorespiratory endurance, muscular strength, and muscular endurance. Data from 6- to 11-year-old participants (n = 499) in the 2012 National Youth Fitness Survey were analyzed. Parents/guardians reported children's PA levels and recess provision, categorized as no/minimal (9.0%), low (26.1%), medium (46.0%), or high (18.9%). Children wore a wrist-worn accelerometer for 7days and completed anthropometric measurements. Fitness was assessed using grip strength and treadmill, pull-up, and plank tests. Cross-sectional linear and logistic regression compared outcomes across levels of recess provision adjusting for the survey's complex sampling design. Children with high provision of recess were 2.31 times more likely to meet PA guidelines according to parent report than those with no/minimal recess. Accelerometer-measured PA followed a more U-shaped pattern, wherein PA was higher in children with high, compared to low, recess provision but comparable to those with no/minimal recess provision. There were no associations with weight status, adiposity, or fitness. Current recess recommendations (20min·d-1) may be insufficient as 30minutes per day of recess was associated with a 2-fold greater likelihood of achieving recommended PA levels. Additional research on recess quantity and quality is needed.

Longitudinal associations between neighborhood child opportunity and physical fitness for New York City public school youth.

Neighborhood environments can support fitness-promoting behavior; yet, little is known about their influence on youth physical fitness outcomes over time. We examined longitudinal associations between neighborhood opportunity and youth physical fitness among NYC public school youth. The Child Opportunity Index (COI), a composite index of 29 indicators measuring neighborhood opportunity at the census tract-level, along with scores on four selected COI indicators were linked to NYC FITNESSGRAM youth at baseline. Fitness outcomes (measured annually, 2011 - 2018) included BMI, curl-ups, push-ups, and PACER laps. Unstratified and age-stratified adjusted three-level generalized liner mixed models, nested by census tract and time, estimated the association between COI and fitness outcomes. The analytic sample (n=204,939) lived in very low (41%) or low (30%) opportunity neighborhoods. Unstratified models indicate that overall COI is modestly associated with improved youth physical fitness outcomes. The strongest opportunity-fitness associations were observed for PACER. Stratified models show differences in associations across younger vs. older youth. We find that neighborhood factors are associated with youth fitness outcomes over time, with the strength of the associations dependent on age. Future implications include better informed place-based interventions tailored to specific life stages to promote youth health.

Abstract 5770: Cardiorespiratory fitness and BMI in youth and five-year mortality after site-specific cancer in men: a population-based cohort study with register linkage

Abstract Aim: Our aim was to assess the associations between cardiorespiratory fitness (CRF) and body mass index (BMI) in youth and five-year mortality following the diagnosis of 18 site-specific cancers in men. Methods: We collected data on all men who underwent military conscription at ages 16-25 from 1968 through 2005 in Sweden. CRF was assessed as maximal aerobic workload on a cycle ergometer test and was classified as low, moderate, or high. BMI (kg/m2) was classified as underweight (&amp;lt;18.5), normal weight (18.5-24.9), overweight (25-29.9), or obesity (&amp;gt;30). Data was cross-linked on individual level through the Swedish unique identification number with follow-up data from national registers with high validity containing information on cancer diagnosis and mortality. Follow-up started at diagnosis and continued until death, emigration, five years after diagnosis, or end of follow-up (2019-12-31), whichever happened earliest. Time-to-event multivariable Cox regression analyses included CRF and BMI as well as age, year, and site of conscription and age at diagnosis. For CRF, primary analyses tested linear trends with categorical comparisons for interpretation while categorical comparisons were primary analyses for BMI. Results: 84,621 cancer cases were included in the main analyses. The mean age at diagnosis of any cancer was 53 years and follow-up data were available during a mean of 6.5 years. Lower CRF and higher BMI were independently associated with higher mortality for several cancer sites (table 1). Conclusion: We report clinically relevant, dose-dependent associations between CRF and BMI in youth and 5-year mortality after diagnosis of 18 site-specific cancers in men. The associations with mortality may be due to both direct cancer inhibition and an improved tolerance to withstand cancer treatment. These results further strengthen the incentive for promoting a healthy lifestyle during the whole lifespan of the population. Table 1. Five-year mortality by cardiorespiratory fitness (CRF) and body mass index (BMI). Cardiorespiratory fitness (ref = low) BMI (ref = normal weight), *= p&amp;lt;0.05, **=p&amp;lt;0.01, ***=p&amp;lt;0.001 Cancer site n cases (% mortality) High p for linear trend for CRF Underweight Overweight Obesity HRR (95% CI) HRR (95% CI) HRR (95% CI) HRR (95% CI) Any cancer 84,621(16%) 0.70 (0.67-0.73) *** 0.98 (0.93-1.04) 1.38*** (1.30-1.46) 1.92*** (1.70-2.17) Malignant skin 28,359(4%) 0.80 (0.69-0.93) *** 0.96 (0.78-1.17) 1.53*** (1.26-1.86) 2.16*** (1.33-3.49) Bronchi and lung 2,502 (68%) 0.82 (0.72-0.94) *** 0.92 (0.80-1.07) 1.06 (0.87-1.28) 1.17 (0.81-1.69) Head &amp; neck 3,549 (20%) 0.69 (0.57-0.84) *** 1.07 (0.84-1.37) 1.52** (1.19-1.94) 1.41 (0.75-2.64) Esophagus 991 (71%) 0.92 (0.76-1.13) 1.00 (0.76-1.32) 1.11 (0.88-1.39) 1.15 (0.75-1.76) Stomach 1,269 (62%) 0.94 (0.78-1.13) 0.95 (0.73-1.23) 1.06 (0.85-1.32) 1.20 (0.78-1.86) Pancreas 1,809 (71%) 0.83 (0.72-0.96) * 1.07 (0.89-1.30) 0.96 (0.80-1.15) 1.38 (0.89-2.16) Liver, bile ducts and gallbladder 1,573 (68%) 0.88 (0.74-1.03) * 1.11 (0.90-1.36) 1.00 (0.81-1.22) 1.14 (0.75-1.71) Colon 4,265 (31%) 0.96 (0.83-1.10) 1.13 (0.94-1.36) 0.99 (0.82-1.20) 1.12 (0.78-1.61) Rectum 3,123 (27%) 0.82 (0.68-0.98) ** 1.01 (0.79-1.28) 1.47** (1.17-1.85) 1.50 (0.93-2.44) Kidney 2,288 (24%) 1.07 (0.86-1.33) 0.70 (0.48-1.02) 1.36* (1.07-1.73) 1.83** (1.20-2.79) Bladder 3,078 (12%) 0.71 (0.55-0.93) * 0.75 (0.51-1.09) 0.93 (0.63-1.39) 2.06* (1.09-3.09) Prostate 19,686(5%) 0.83 (0.70-0.97) ** 0.83 (0.66-1.05) 1.30* (1.02-1.66) 2.43** (1.40-4.21) Central nervous system 2,937 (1,566) 0.89 (0.78-1.02) 1.05 (0.88-1.27 1.03 (0.85-1.23) 0.94 (0.58-1.52) Thyroid gland 848 (11%) 0.94 (0.55-1.62) 1.27 (0.60-2.69) 1.36 (0.69-2.68) 3.53** (1.41-8.83) Leukemia 2,698 (24%) 0.98 (0.80–1.20) 1.46** (1.12-1.89) 0.96 (0.73-1.28) 1.34 (0.77-2.33 Myeloma 1,209 (21%) 1.19 (0.86-1.65) 1.66* (1.06-2.58) 1.40 (0.93-2.09) 0.71 (1.18-2.88) Hodgkin's lymphoma 1,112 (10%) 0.82 (0.49-1.36) 1.55 (0.85-2.84) 0.89 (0.47-1.69) 2.47 (0.98-6.21) Non-Hodgkin's lymphoma 3,261 (16%) 0.77 (0.62-0.96) ** 0.81 (0.57-1.14) 1.14 (0.86-1.52) 1.26 (1.03-1.24) Citation Format: Aron Onerup, Kirsten Mehlig, Agnes af Geijerstam, Elin Ekblom-Bak, Hans-Georg Kuhn, Lauren Lissner, Mats Börjesson, Maria Åberg. Cardiorespiratory fitness and BMI in youth and five-year mortality after site-specific cancer in men: a population-based cohort study with register linkage. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5770.

Peculiarities of physical training of students when learning swimming

The purpose of the work: to reveal the peculiarities of physical training of students during swimming lessons. Methodology: theoretical research methods were used, in particular, analysis and generalization of methodological, psychological-pedagogical and educational-methodical literature, which made it possible to determine the peculiarities of physical training of students during swimming lessons. Scientific novelty: the current state of health and physical fitness of student swimmers was analyzed, a complex of problems related to the development of sports and mass swimming in Ukraine was identified, in particular, the training of the country's population and its conscript contingents in the ability to swim. The role and place of swimming in the system of physical fitness of student youth and ensuring their adherence to the basics of a healthy lifestyle are defined. Conclusions: as a result of the analysis of literary sources, it was found that swimming has a positive effect on the culture of movements, allows you to control your movements in the water, and this, in turn, has a positive effect on improving the level of development of physical qualities and moral and willpower, on increasing speed and strength readiness. In addition, the appropriate use of swimming equipment guarantees the emotionality of classes and the versatile physical impact on various muscle groups, allows to increase the level of development of the components of physical fitness, the interest of students, the motor density of classes and the realization of both a health-improving task and the formation of a solid foundation of work capacity for a long and active life of an individual. It is important to use the means of physical fitness when learning to swim, taking into account the balanced volumes of physical exertion, of different orientations, which allow to ensure the effectiveness of the pedagogical influence on solving the health-improving task and obtaining a long-term training effect, taking into account the age, gender and professional characteristics of the contingent.

IMPLEMENTATION OF HEALTH-SAVING TECHNOLOGIES IN SWIMMING LESSONS

The article defines the peculiarities of the implementation of health-saving technologies in swimming lessons in higher education institutions. Modern health-saving technologies used in the field of physical education of student youth are disclosed. The current state of health and physical fitness of student swimmers was analyzed, a set of problems related to the development of sports and mass swimming in Ukraine was identified, in particular, regarding the training of the country's population and its conscript contingents in the ability to swim. The role and place of swimming in the system of physical fitness of student youth and ensuring their adherence to the basics of a healthy lifestyle in the context of the implementation of health-saving technologies are determined.&#x0D; Swimming training is carried out in the form of practical classes, which take up one training pair (2 academic hours).&#x0D; Methodical planning and structuring of the training process, which includes the logical and systematic ordering of several training variables (intensity, volume, frequency, recovery period and exercises) in an integrative way aimed at optimizing specific performance results at predetermined points in time.&#x0D; The main characteristics of such approaches are systematic variations in the content of the intensity of classes and the amount of workload throughout the entire program.&#x0D; However, this should not be seen as a simple strategy of training variation, but as an appropriate sequence and integration of different training variables, including not only volume and intensity, but also frequency, recovery periods, density and selection of exercises.&#x0D; The duration of each session may increase. The total training contribution of strength work on land is a product of intensity, frequency and duration of training. The general goal is the uniform development of all muscle groups.&#x0D; Land exercises are used to train muscular strength and endurance, and they complement the improvements in muscular endurance that result from swimming training. The exercise program should be simple (that is, two exercises for each of the main muscle groups) so that it corresponds to the total training time for one session.

The general characteristics and historical aspect of the emergence and development of aerobics as a type of motor activity of the applicants of the higher education

Today, applicants of the higher education institutions have a low level of physical activity, which leads to hypokinesia, which in turn leads to poor health. The decrease in motivation and interest of the student youth in the physical education classes is one of the significant negative factors of the physical activity deficit. Therefore, a promising step in solving this problem is the use of popular types of physical activity in the physical education of the applicants that encourage young people to exercise.&#x0D; In recent years, the emergence of interest in aerobics classes has become particularly noticeable, gaining popularity year after year. They are one of the most affordable and effective forms of health-improving effects; they help to improve physical and functional condition; increase the level of physical activity.&#x0D; The aim of the study is to provide a general description and study the historical aspect of the emergence and development of aerobics as a type of motor activity of the applicants of the higher education. To achieve the purpose of the study, theoretical analysis and generalization of scientific and methodological literature were used. Results of the study. The article characterizes aerobics as a sport and physical activity. The historical aspect of the emergence and development of aerobics as a means of physical activity of the applicants of the higher education. Conclusions.&#x0D; Modern aerobics is a dynamic motor activity that is constantly changing and updating its arsenal of tools, new directions and types of aerobics appear using a variety of tools and applying different methodological techniques.&#x0D; The aerobics is one of the main means of improving health, improving physical and functional condition, increasing the level of physical fitness and performance in the student youth. From a large number of types of aerobics, each the applicants of the higher education can choose the one that suits his or her age, gender, health, physical fitness, personal preferences, and goals.

Severe obesity and fitness in New York City public school youth, 2010–2018

BackgroundObesity is associated with poorer youth fitness. However, little research has examined the magnitude of this relationship in youth with severe obesity. Therefore, we sought to determine the relationship between increasing weight status and fitness within a sample of children and adolescents from New York City public schools.MethodsThis study utilized longitudinal data from the NYC Fitnessgram dataset years 2010–2018. Height and weight along with fitness were measured annually during physical education classes. Severity of obesity was defined using body mass index relative to the 95th percentile and then categorized into classes. A composite measure of fitness was calculated based on scores for three fitness tests: aerobic capacity, muscular strength, and muscular endurance. To examine the weight status-fitness relationship, repeated measures mixed models with random-intercepts were constructed. Stratified models examined differences by demographic factors.ResultsThe sample included 917,554 youth (51.8% male, 39.3% Hispanic, 29.9% non-Hispanic Black, 14.0%, 4.6%, and 1.6% class I, II and III obesity, respectively). Compared to youth with healthy weight, increasing severity of obesity was associated with decreased fitness: overweight (β = − 0.28, 95% CI:-0.29;-0.28), class I obesity (β = − 0.60, 95% CI:-0.60; − 0.60), class II obesity (β = − 0.94, 95% CI:-0.94; − 0.93), and class III obesity (β = − 1.28; 95% CI:-1.28; − 1.27). Stratified models showed the association was stronger among male and non-Hispanic White youth.ConclusionFindings revealed that more severe obesity was associated with lower fitness. Future research is needed to develop targeted interventions to improve fitness in youth with obesity.

Designed acute physical activity to benefit primary school children’s cognition: Effects of cognitive challenge, bout duration and positive affect

Designed acute physical activity to benefit primary school children’s cognition: Effects of cognitive challenge, bout duration and positive affect

Design of Metaverse-Based Physical Fitness Service for the Enhancement of Exercise Capability for Youth

This study explains the case study to develop a metaverse-based training system for the management of the physical fitness of youth. The study targeted developing a smart mirror-based AR physical fitness system and a bone age-based physical fitness management service to enhance exercise capability in youth. Accordingly, the data on youth’s bone age, physical strength, and physique were collected. Based on the collected data, the stage of the human development in youth was categorized, and the physical fitness management system providing the exercise program customized for the phases of physical development was implemented. Furthermore, a solution was devised so that youth with less physical exercise experience could practice physical fitness training without a coach using the smart mirror-based AR physical fitness system. This system uses an RGB-D camera and a three-dimensional posture estimation algorithm to recognize a user’s movement, determine movement accuracy, and provide feedback for the improved exercise effect. The XR Physical Fitness, using a smart mirror implemented in this article, features two features of metaverse’s augmented reality and lifelogging, enabling the youth to enjoy more immersive and enjoyable exercise experiences.

Influence of Volume and Bouts of Sedentary Time and Physical Activity on School-Aged Youth’s Physical Fitness: The UP &amp; DOWN Longitudinal Study

The aim of this study was to examine associations of total volume and bouts of sedentary time (ST) and moderate to vigorous physical activity (MVPA) with physical fitness (PF) in youth. This was a 2-year follow-up study with 1418 children and adolescents (51.7% boys). Accelerometers were used to assess ST and MVPA. Cardiorespiratory and muscular fitness values were objectively measured and combined in a global PF variable. Weight status was objectively obtained. Linear regression analyses were used to examine the cross-sectional (using scores at baseline) and longitudinal associations (using the change in the variables) of total volume and bouts of ST and MVPA with PF. Total ST was negatively associated with global PF (β = -0.488, P < .001 in cross-sectional analysis; β = -0.234, P = .003 in longitudinal analysis). However, this association was not independent of MVPA. Total volume of MVPA showed a positive association with global PF independently of ST and weight status (β = 0.285, P < .001 in cross-sectional analysis; β = 0.119, P = .001 in longitudinal analysis). Longitudinal associations found between ST and MVPA accumulated in bouts of various lengths and global PF became nonsignificant when their respective total volumes are included in the model. These results underline the need to accumulate minutes of MVPA, regardless of the bout duration, to increase PF levels in youth.

Heart Rate Variability and Cardiorespiratory Fitness in Youth Populations: The Impact of Heart Rate on Data Analysis.

The positive association between heart rate variability and cardiorespiratory fitness in youth populations is unclear. In this regard, several methodological aspects related to heart rate variability analysis could partially explain the disagreement between studies. To the best of the authors' knowledge, the influence of the heart rate on data analysis is unclear. In the present short communication, we discuss the impact of the heart rate on the associations between heart rate variability and cardiorespiratory fitness in youth. In addition, we proposed some aspects that should be considered for statistical analyses when the relationship between heart rate variability and cardiorespiratory fitness is studied. Finally, we should acknowledge that these recommendations may be applicable for other health-related outcomes different than cardiorespiratory fitness (e.g., inflammatory markers, cognition, cardiovascular disease status).

Effects of athletic training on physical fitness and stroke velocity in healthy youth and adult tennis players: A systematic review and meta-analysis.

Better physical fitness and stroke velocity in healthy elite compared to sub-elite tennis players have been shown in previous studies. However, evidence-based knowledge regarding the effectiveness of athletic training on physical fitness and stroke velocity is currently lacking. Thus, the objective of this systematic review with meta-analysis was to characterize, aggregate, and quantify athletic training effects on measures of physical fitness and stroke velocity in healthy youth and adult tennis players. A computerized systematic literature search was performed in the databases PubMed, Web of Science, and SportDiscus from their inception date to August 2022. Studies were included, among others, if the intervention period lasted a minimum of four weeks and if at least one parameter of physical fitness (i.e., speed, agility, lower-extremity muscle power, upper-extremity muscle power/strength, endurance, balance, flexibility) or stroke performance (i.e., stroke velocity) was tested. Initially, 11,511 articles were identified, after removing duplicates and assessing abstracts and full texts, 24 articles were used to calculate weighted standardized mean differences (SMD). For measures of physical fitness, athletic training resulted in small (speed: SMD = 0.44), moderate (endurance: SMD = 0.61, upper-extremity muscle power: SMD = 0.72; flexibility: SMD = 0.63), and large (agility: SMD = 0.93, lower-extremity muscle power: SMD = 0.88; upper-extremity muscle strength: SMD = 0.90; balance: SMD = 0.88) effects. Further, a large effect (SMD = 0.90) on stroke velocity was detected. The additionally performed sub-analyses showed differences in the effectiveness of athletic training on variables of physical fitness and stroke speed when considering players' age (i.e., youth players: <18 years; adult players: ≥18 years). Precisely, there was a high potential for training-related adaptations in adult players with respect to lower-extremity muscle power, upper-extremity muscle strength, and stroke velocity and in youth players with respect to endurance. Interventions to promote physical fitness and stroke velocity in healthy tennis players revealed varying levels of effectiveness ranging from small to large and these were additionally affected by players' age. Therefore, future studies should investigate modalities to increase training efficacy in youth and adult tennis players, especially for fitness components that showed small- to moderate-sized changes.

PREREQUISITES FOR THE FORMATION OF MOTIVATION FOR PHYSICAL EDUCATION CLASSES IN STUDENTS OF NON-PHYSICAL SPECIALTIES

It has been established that the health and physical fitness of non-physical education students are the most important components of the health and physical potential of the entire society. Currently, physical education in educational institutions is practically relegated to the last plan, and it is not surprising that the level of physical fitness of children and youth is assessed as extremely unsatisfactory. The low level of physical fitness of students worsens their adaptation to the regime of future work, especially to the conditions of military service. Many facts cause acute concern for the health of the future generation. Chronic lack of motor activity inhibits their normal physical development and threatens health.

Strength versus aerobic program: effects on body composition and health-related physical fitness levels of youths with Down syndrome

Aims: To determine the effect of a 16-week fitness program (strength vs. aerobic) on different indicators of body composition and components of health-related physical fitness in youths with Down syndrome. Methods and procedures outcomes: Fifty adolescents (19 girls and 31 boys; average age, 18.33 ± 1.42 years) with Down syndrome were recruited and randomized to two groups (strength group vs. aerobic group). Adolescents allocated in the aerobic group carried out a physical activity program three times a week for 16 weeks meanwhile adolescents allocated in the strength group performed a fitness program three times a week for 16 weeks. Results: The exercise group had significant improvements in all health-related physical fitness variables (p < .05) but not on body composition. Conclusions and implications: A sixteen week fitness program consisting of three sessions of 60 min is able to increase levels of health-related physical fitness but not on body composition in youths with Down syndrome. The aerobic program does not seem to show significant differences.

Potential relevance of a motor skill “proficiency barrier” on health-related fitness in youth

ABSTRACT This study investigated the potential impact of a motor skill proficiency barrier on measures of cardiorespiratory (CRF) and musculoskeletal (MSF) fitness in youth. A sample of 241 youth (114 girls) aged 10 - 18 years, completed the Motor Competence Assessment battery with composite scores indexed according to age- and gender-adjusted percentile scores. Motor competence (MC) levels were categorized as low (≤ 25%tile – proficiency barrier), moderate (≥ 26%tile to < 75%tile), and high (≥ 75%tile). CRF levels (Health Risk, Needs Improvement, and Healthy) were assessed using the Fitnessgram® 20 m PACER test. Low (≤ 20%tile), moderate (≥ 21%tile to ≤ 80%tile), and high (≥ 80%tile) MSF levels were assessed using grip strength normative data. Two 3 × 3 chi-square tests were conducted to determine the probability of MC level predicting CRF and MSF levels. Results demonstrated statistically significant models for performance on both the PACER (χ2[4, N = 241] = 22.65, p < .001) and grip strength (χ2[4, N = 241] = 23.95, p < .001). Strong evidence of a proficiency barrier impacting CRF was noted, as no low skilled youth met the “Healthy” fitness zone standards for PACER performance. Evidence supporting a barrier with grip strength was not as strong, as 20.8% of youth exhibiting low MC displayed high grip strength. However, all individuals with high levels of MC demonstrated at least moderate grip strength. Results emphasize the importance of developing MC during childhood as it may provide a protective effect against unhealthy CRF and MSF across youth. Highlights These data support the notion of Seefeldt’s (1980) proficiency barrier as it relates to CRF, as no youth demonstrating low MC met the healthy fitness zone criteria for PACER performance. The development of MC may both directly and indirectly provide a protective effect against unhealthy CRF levels across childhood and adolescence. Evidence supporting a proficiency barrier with MSF as measured by grip strength was not as strong; however, all individuals with high levels of MC demonstrated at least moderate grip strength. Thus, the development of MC may be a protective factor to mitigate low levels of MSF via enhanced neuromuscular function. Promoting the development of MC in a variety of developmentally appropriate activities and settings (e.g. MC skills practice, structured and unstructured play, and performance contexts) is important to promote positive trajectories of CRF and MSF across childhood and adolescence.