Lower Limb Explosive Strength Research Articles

Cardiac rehabilitation in children and adolescents with long QT syndrome: the RYTHMO’FIT pilot study

BackgroundTo assess the feasibility, acceptability, safety, and short-term benefits of a tailored cardiac rehabilitation program for children and adolescents with long QT syndrome (LQTS).MethodsEight participants, aged between 6 and 18, with a positive LQTS genotype and impaired cardiorespiratory fitness, were enrolled in a 12-week centre-based cardiac rehabilitation program. The program included supervised exercise training group sessions (aerobic, resistance, and outdoor activities) and patient education workshops. Feasibility, acceptability, and safety of the program were prospectively monitored. Feedback from the parents, children, and professionals involved was collected from qualitative interviews. Short-term effects on cardiorespiratory fitness, muscle fitness, physical activity, and health-related quality of life (HRQoL) were measured between baseline and the end of the program.ResultsRetention (88% with one participant dropping out) and adherence (79%) rates were good, and no cardiac events occurred during the 12-week intervention period. Participants, parents, and healthcare professionals expressed a high level of satisfaction with the program. A significant increase between the beginning and the end of the program was observed for ventilatory anaerobic threshold (21.7±5.2 vs. 28.7±5.1 mL/kg/min, P=0.01, effect size=0.89), grip strength, (18±5.3 Kg vs. 20±4.7 Kg, P=0.02, effect size=0.90), lower limb explosive strength (142±36.5 cm vs. 148±24 cm, P=0.02, effect size=0.90), and parent-reported physical health dimension of HRQoL (65.6±9.75 vs. 84.4±20.35, P=0.03, effect size=0.87).ConclusionsA 12-week tailored centre-based cardiac rehabilitation program was feasible, acceptable, and safe for children with LQTS. Cardiac rehabilitation for children with LQTS presents a new approach aligned with secondary prevention in youth with cardiac diseases.Trial registrationThe trial was registered at Clinicaltrials.gov (NCT05964322, registration date: 27/07/2023).

Explanatory Model for Elite Canoeists’ Performance Using a Functional Electromechanical Dynamometer Based on Detected Lateral Asymmetry

Canoe modality in flatwater canoeing has a clear asymmetrical nature. This study aimed (1) to determine the magnitude and direction of neuromuscular properties, range of motion (ROM) and lower-limb strength asymmetries in female and male canoeists; (2) to establish sex-individualized asymmetry thresholds for canoeists’ neuromuscular properties, ROM and lower-limb strength; and (3) to determine the relationship of canoeists’ neuromuscular properties, ROM and lower-limb strength asymmetries with a specific canoe–dynamometer performance test. Twenty-one international canoeists were assessed through tensiomyography (TMG), ROM, lower-limb explosive strength, and a specific canoe incremental dynamometric test. The magnitude of asymmetry assessed through TMG and ROM was not modulated either by sex or performance level (international medal vs. non-medal). Females showed greater asymmetry than males on muscle tone of the erector spinae towards non-stroke side (22.75% vs. 9.72%) and the tibialis anterior (30.97% vs. 16.29%), and Fmax in explosive leg press (2.41% vs. 0.63%) towards the stroke side. International medalists showed greater asymmetry in semitendinosus contraction time towards non-stroke side (20.51% vs. 9.43%) and reached Vmax earlier in explosive leg press towards stroke side leg (19.20% vs. 9.40%). A greater asymmetry in Fmax and in Vm, and a smaller asymmetry in Tvmax and in leg press showed a small predictive capacity for canoeists’ performance on a specific canoe incremental dynamometry test. Reporting reference data from world-class canoeists’ asymmetries can be of great importance for coaches to periodically control lateral asymmetry.

Effects of Taekwondo Poomsae Training on Lower Limb Reaction Ability and Balance Performance in Adolescents

<p>背景：學習跆拳道運動有助於兒童與青少年成長與體適能表現，但學習跆拳道品勢的研究較少，因此本研究希望了解學習跆拳道品勢訓練後的身體適能表現。目的：探討從事8週跆拳道品勢訓練後，對國中少年下肢爆發力、反應能力與平衡能力的影響。方法：招募未有運動習慣及跆拳道訓練經驗之男性國中生16名，隨機分配實驗組 (n = 8)(參與學校體育課程+跆拳道品勢訓練)，控制組 (n = 8)(學校體育課程)，進行8週的訓練課程。訓練前後進行身高體重及腿長測量、動態平衡能力、反應能力及下肢爆發力的測驗，並以混合設計二因子變異數分析，比較兩組別反應能力與平衡能力之差異，當交互作用達顯著時，以LSD法進行事後比較。以獨立樣本t檢定考驗實驗組與訓練組進步百分比是否有達顯著性，並以皮爾森績差相關分析與受試者下肢平衡能力與反應能力的相關性。結果：實驗組與控制組在爆發力與平衡表現上組別因子上達到顯著差異 (p < .05) 且實驗組與控制組進步百分比也達顯著差異 (p < .05)。反應能力組別因子與時間因子未達顯著差異 (p > .05)，進步百分比也未達顯著差異 (p >.05)。訓練前反應能力與平衡表現為低度相關 (r = .352 , p = .10)，訓練後反應能力與平衡表現之間達中度相關 (r = .665，p < .05)。結論：跆拳道品勢訓練可以顯著提升國中少年的下肢爆發力與下肢平衡能力。爆發力、反應能力、平衡表現進步幅度都大於控制組。訓練後反應能力與平衡表現之間存在相關性，可能是跆拳道品勢訓練提升了學童身體協調與感覺統合。未來可針對不同跆拳道訓練方式與不同年齡層了解訓練與身體發展的差異。</p> <p> </p><p>Background: Learning Taekwondo can contribute to the growth and physical fitness performance of children and adolescents. However, there is limited research on learning Taekwondo Poomsae. Therefore, this study aims to understand the impact of learning Taekwondo Poomsae on physical fitness performance. Purpose: The purpose of this study was to investigate the effects of 8 weeks of Taekwondo Poomsae training on lower limb explosive strength, reaction ability, and balance in junior high school adolescents. Methods: Sixteen male junior high school students with no prior sports experience or Taekwondo training were recruited. The participants were randomly assigned to either the experimental group (n = 8) (participating in school physical education classes plus Taekwondo Poomsae training) or the control group (n = 8) (participating only in school physical education classes). Both groups underwent an 8-week training program. Before and after the training, all participants underwent measurements of height, weight, leg length, dynamic balance ability, reaction ability, and lower limb explosive strength. The participants’ data were analyzed using a mixed-design two-factor analysis of variance to compare the differences in reaction ability and balance ability between the two groups. When the interaction effect was significant, post hoc comparisons were performed using the LSD method. Independent sample t-test was used to test the significance of improvement percentage between the experimental and control groups. Pearson correlation analysis was used to examine the relationship between lower limb balance ability and reaction ability. Results: The experimental group showed significant differences in explosive strength and balance performance compared to the control group (p < .05). Moreover, the improvement percentages in both explosive strength and balance performance were significantly different between the two groups (p < .05). However, there were no significant differences in reaction ability between groups or in the improvement percentage (p > .05). Before the training, there was a low correlation between reaction ability and balance performance (r = .352, p =.10). After the training, there was a moderate correlation between reaction ability and balance performance (r = .665, p < .05). Conclusion: Taekwondo Poomsae training can significantly improve lower limb explosive strength and balance in junior high school adolescents. The improvement in explosive strength, reaction ability, and balance performance was greater in the experimental group than the control group. The correlation between reaction ability and balance performance after training suggests that Taekwondo Poomsae training may enhance the students’ body coordination and sensory integration. Future studies could explore the differences in training and physical development across different Taekwondo training methods and age groups.</p> <p> </p>

Effect of tDCS Combined With Physical Training on Physical Performance in a Healthy Population

ABSTRACT Purpose: The effectiveness of transcranial direct current stimulation (tDCS) combined with physical training has shown inconsistent results through research. Hence, a study utilizing a long-term tDCS application over the primary motor cortex and a large sample size is required to determine whether tDCS combined with physical training can increase physical performance (muscular strength, endurance, and explosive strength) in healthy adults. Material and methods: Fifty-six healthy adults were randomly distributed into two groups: active (active tDCS+ physical training) and sham (sham tDCS + physical training) and received the intervention three times per week for six weeks. Muscle strength was assessed using maximal isometric muscle strength (MIMS) by a digital dynamometer. Muscular endurance and lower limb explosive strength were assessed by using muscle fitness testing (MFT), and the Sargent jump test. Results: The active and sham groups exhibited significant improvement in all measured parameters in intragroup analyses. However, intergroup analyses revealed no significant difference between the groups. Conclusion:Our findings suggest that only physical training improved MIMS in the upper and lower extremities, MFT endurance scores, and lower limb explosive power. Thus, tDCS failed to demonstrate its effectiveness in a healthy population according to the protocol used in this study.

Dynamic balance and explosive strength appears to better explain single leg hop test results among young elite female basketball athletes

To analyze the impact of balance, lower-limb explosive strength and anthropometric variables on the result of the hop test in young elite female basketball athletes. Ninety young elite female basketball athletes (13–17 years), without current or recent lower-limb injury, were assessed in the off-season period of July 2021. Single leg hop test, countermovement jump, Y balance test and anthropometric outcomes were assessed. A correlation study and a regression model were performed to investigate the influence of such outcomes and the value of their participation on the hop test results. It was found a low-to-moderate correlation effect size for both countermovement jump (distance and power flight) and Y balance test values (except interlimb outcomes) with the single leg hop test results. Anthropometric outcomes did not show significant correlation (p > 0.05). Regression model revealed that for right hop test, countermovement jump values exhibited an adjusted determination coefficient of 0.408, (β = 0.249, p = 0.013), For left hop test, again the countermovement jump values (β = 0.229, p = 0.025), and left Y balance test values (β = 0.331, p = 0.011) jointly obtained an adjusted determination coefficient of 0.263 significant predictive value for countermovement jump outcomes in both right (β = 0.249, p = 0.013; β = 0.301; p = 0.031) and left leg (β = 0.229, p = 0.025; β = 0.365, p = 0.040), as well as certain Y balance outcomes values. Explosive strength, and dynamic balance although to a lesser extent, appear to be the most relevant physical-functional factors influencing the single leg hop test results among young elite female basketball athletes. These findings may a serve as a basis to implement targeted interventions, such as plyometric and balance training, for an enhancement on functional rehabilitation and reducing the risk of injury related to the hop test results.

Meta-Analysis of the Effects of Plyometric Training on Lower Limb Explosive Strength in Adolescent Athletes.

Plyometric training is an effective training method to improve explosive strength. However, the ability to perform plyometric training in the adolescent population is still controversial, with insufficient meta-analyses about plyometric training on lower limb explosive strength in adolescent athletes. To investigate the influence of plyometric training on the explosive strength of lower limbs in adolescent athletes. We performed a search of six databases (Web of Science, PubMed, Scopus, ProQuest databases, China National Knowledge Infrastructure (CNKI), and Wan-fang database) from the starting year of inclusion in each database to April 4, 2022. The quality of the included literature was assessed using the Cochrane risk assessment tool, and data were analyzed using the Review Manager 5.4 software. Plyometric training had significant effects on the performance of adolescent athletes in countermovement jump (MD = 2.74, 95% CI: 1.62, 3.85, p < 0.01), squat jump (MD = 4.37, 95% CI: 2.85, 5.90, p < 0.01), standing long jump (MD = 6.50, 95% CI: 4.62, 8.38, p < 0.01), 10-m sprint (MD = -0.04, 95% CI: -0.08, -0.00, p = 0.03), and 20-m sprint (MD = -0.12, 95% CI: -0.20, -0.04, p = 0.03); all had positive and statistically significant effects (p < 0.05). Plyometric training can significantly enhance the explosive strength of lower limbs in adolescent athletes.

The effects of experimental program on the explosive strength of lower limbs in male adolescents

Background and Study Aim. Various experimental programs for the development of motor skills are present in sports activities. Explosive strength can be defined as the ability to produce maximum force as soon as possible, and it represents an essential factor in activities where it is necessary to increase the acceleration of the body mass, the mass of specific body parts, or of an external object. The aim of study – to determine the effects of an experimental program on the explosive strength of lower limbs in male adolescents.&#x0D; Material and Methods. One hundred and one male adolescent (aged 19 years ± 6 months; body height 181.43 ± 7.42 cm; body mass 80.08 ± 10.07 kg) were recruited and randomly divided into two groups: experimental group (E; N=48) and control group (K; N=48). The E group performed the experimental program which lasted fifteen weeks and consisted of three 60-min training sessions per week. All participants were tested on Squat Jump (SJ), Countermovement Jump (CMJ), Countermovement Jump with arms (CMJa) and Continuous Jump with Straight Legs (CJSL). The four tests were performed using a Kistler force platform to measure Quatro Jump Bosco Protocol Version 1.0.9.2 and gave us data about the jump height, number of jumps for 15s, average power jump and peak power jump. The multivariate analysis covariance (MANCOVA) and follow up analysis covariance (ANCOVA) were used to analyze the data.&#x0D; Results. The results of MANCOVA showed statistically significant differences (p ≤ 0.001) between the E and K groups in all systems of variable lower limb explosive strength in male adolescents. In addition, results of ANCOVA showed statistically significant differences (p ≤ 0.001) in SJ, CMJ, CMJa and CJSL in favor of the E group compared to the K one.&#x0D; Conclusions. The results of this research show that a fifteen-week experimental program can lead to significant improvements in lower limb explosive strength in male adolescents.

Effects of chains squat training with different chain load ratio on the explosive strength of young basketball players' lower limbs.

The purpose of this study was to explore the effects of the chain squat training (CST) with different chain load ratio (0, 10%, 20% and 30%) on the explosive power of the lower limbs of adolescent male basketball players. Forty-four youth basketball players (age 15.48 ± 0.81 years, body mass 78.86 ± 12.04 kg, height 184.95 ± 6.71 cm) were randomly allocated to one of the four groups: traditional squat training (TST), 10% chains squat training (10% CST), 20% chains squat training (20% CST), and 30% chains squat training (30% CST). Training interventions were performed 2 times per week for 6 weeks, and at the week before (Pre) and after (Post) the 6-week CST program with different chain load ratio, the no-step vertical jump, standing long jump, 15 m shuttle run, 1 R M squat and 30 m sprint test were performed. A 4 (group) × 2 (time) repeated measures analysis of variances (ANOVA) was calculated to show the scatter of each variable, and the Bonferroni’s post-hoc test was used for multiple comparisons, in addition the partial eta-squared (η2) was calculated as an estimate of the ES. Significant time × group interaction was noticed for the no-step vertical jump (p < 0.001; η2 = 0.611), standing long jump (p < 0.001; η2 = 0.490) and 1 R M squat (p < 0.01; η2 = 0.333) indicating that better improvements appear in CST compared to TST. However, significant time × group interaction was noted for 15 m shuttle run (p < 0.001; η2 = 0.428), in favor of TST compared to CST. In addition, the improvements in 30 m sprint were similar between all groups. In conclusion, CST with more chain load has better training effects on lower limb explosive strength and maximum strength, based on the improvement in 1 R M squat and jumping performance. Besides, compared with TST, CST with more chain load might not help to develop better velocity adaptation at higher range of movement.

Comparison of Selected Characteristics of Slovak and Polish Representatives in Kickboxing.

Background: Previous kickboxing studies conducted over the last three decades have focused on improving performance through physical fitness characteristics; however, most of the research focused on men. The objective of this study is to assess the level of physical fitness of Slovak and Polish female kickboxers in the highest sport level as well as to compare the differences between them. Methods: The study included 20 female kickboxers on the highest level of sport performance, 10 from Slovakia (body mass—53.59; height—166.45) and 10 from Poland (body mass—60.35; height —169.95), from senior categories, with a mean age of 23 ± 2. The selection criteria included training experience and sports level. The level of physical fitness was evaluated by the following tests: Cooper’s test, 50 m sprint, sit-ups, flexed arm hang and standing long jump. Technical and tactical indicators were used to assess the sports skill level during the competition. Results: The test results of both groups are very comparable based on the evaluated data of Kruskal–Wallis ANOVA. The attack activity index together with sit-ups demonstrated statistically significant differences (p < 0.05) between Slovak and Polish kickboxers. A strong positive correlation was proven between technical and tactical indicators and physical fitness tests in the results of both groups. Conclusions: There exists a positive correlation between the technical and tactical indicators of kickboxers and the explosive strength of lower limbs, strength endurance, abdominal muscle strength, speed and aerobic endurance. Differences between Slovak and Polish kickboxers have been shown in the attack activity index and in the level of strength endurance. The level of speed and explosive power of the lower limbs was comparable in both groups of kickboxers.

Informativeness of vertical jump attempts with deferring spatial structure in speed climbing

Aim. Vertical jump tests (VJT), used in the study among speed climbers, have shown that lower limb explosive strength is an important factor determining success in this sport. However, the correlation coefficients between VJT and climb time reported in the literature indicate: poor to good validity of using the results of these tests as a means of controlling athlete preparation. The purpose of this study was to assess the informative nature of the VJT of varying technical complexity on an athlete’s preparation for competition. Materials. The material of the study was a group of 5 women (x̃=23.8 years) and 5 men (x̃=20.8 years), members of the Polish National Team. The following tests were performed: CMJ without sweep (CMJbz), CMJ with sweep (CMJ), CMJ with rotation about the body axis (CMJ 360), ten (10) CMJ jumps with sweep at 2/3 of the height of the CMJ jump with sweep, motor reaction time (RT) to a sound signal. Results and Conclusions. Our results showed that of the trials used, only the CMJ with swing (CMJ), CMJ without swing (CMJws), and CMJ with rotation (CMJ-360) were most accurate. The CMJ-360 trial, which was of higher complexity, indicated the highest accuracy and the lowest estimation error of the expected speed climb time.

Differentiation of the somatic structure and the level of motor potential of athletes in mixed martial arts (MMA) and Brazilian jiu-jitsu (BJJ) sections

The aim of the research was to assess the differentiation of the body structure and the level of motor potential of the athletes practising different disciplines in the field of combat sports in Legion Team Sports Club in Tarnów. The athletes, aged 19-20, with training experience of 3-5 years, were compared in two groups. The first group consisted of athletes practising mixed martial arts, so called MMA, and the other group, of athletes practising Brazilian ju-jitsu, so called BJJ. 30 practitioners were examined. The basic elements of the somatic structure, i.e. body height, body weight, body fat content and BMI were measured and BMI indexes were calculated. Selected manifestations of motor potential were also measured: static balance, plain reaction time to a visual stimulus, trunk flexibility, static strength of forearms, relative strength, explosive strength of lower limbs, MAW, muscle activation speed and resistance of abdominal muscles to fatigue as anaerobic strength. In the course of the analyses it was found that: the body structure of the athletes training in different combat sports sections does not significantly differentiate them. The athletes in both (BJJ and MMA) sections displayed a similar level of the basic somatic build. The level of motor skills in the BJJ and MMA sections significantly differentiated the athletes in these sections in terms of static strength (p = 0.045), relative strength (p = 0.044) and fatigue resistance, i.e. anaerobic strength (p = 0.002). The higher level of these elements of motor skills was demonstrated by the BJJ section athletes.

Impact of Explosive Strength of Lower Limbs on Skating and Running Speed on a 10 M Distance in 14-15 Years Old Ice Hockey Players

Impact of Explosive Strength of Lower Limbs on Skating and Running Speed on a 10 M Distance in 14-15 Years Old Ice Hockey Players

Italian Physical Fitness Decline: A True Fact or a Mindset? A 10-Year Observational Perspective Study.

Evidence regarding a putative physical fitness decline remains less well documented for Italian children and adolescents. An update review of data collection articles was undertaken concerning motor performances (power, strength, speed-agility and indirect cardiorespiratory fitness) of children and adolescents worldwide and compared with 2859 11–12-year-old Italian students of both sexes, throughout a ten-year observational period. Lower limb explosive strength (standing broad jump), flexibility (sit-and-reach), endurance (Cooper) and speed (SP-30) performances of sixth grade Italian students showed nearly stable trends, with no differences during the observed decade, in both sexes. This 10-year perspective study confirmed that Italian physical fitness levels flatlined rather than actually declined. According to these study data, the decline in physical fitness of the Italian youth is ostensible and needs a further in-depth analysis.

Explosive Strength Modeling in Children: Trends According to Growth and Prediction Equation

Lower limb explosive strength has been widely used to evaluate physical fitness and general health in children. A plethora of studies have scoped the practicality of the standing broad jump (SBJ), though without accounting for body dimensions, which are tremendously affected by growth. This study aimed at modeling SBJ-specific allometric equations, underlying an objectively predictive approach while controlling for maturity offset (MO). A total of 7317 children (8–11 years) were tested for their SBJs; demographics and anthropometrics data were also collected. The multiplicative model with allometric body size components, MO, and categorial differences were implemented with SBJ performance. The log-multiplicative model suggested that the optimal body shape associated with SBJs is ectomorphic (H = −0.435; M = 1.152). Likewise, age, sex, and age–sex interactions were revealed to be significant (p &lt; 0.001). Our results confirmed the efficacy of the allometric approach to identify the most appropriate body size and shape in children. Males, as they mature, did not significantly augment their performances, whereas females did, outperforming their peers. The model successfully fit the equation for SBJ performance, adjusted for age, sex, and MO. Predictive equations modeled on developmental factors are needed to interpret appropriately the performances that are used to evaluate physical fitness.

Longitudinal development of 5m sprint performance in young female tennis players

ABSTRACT Sprint performance over short distances is a central component in young tennis players’ development. This study aimed to examine the longitudinal development of sprint performance in young female tennis players, and to investigate differences between performance levels. Also potentially explanatory variables were investigated. Female tennis players aged 10–15 (N = 167) participated in a, mixed-longitudinal study (n = 48 elite; n = 119 sub-elite). Players were measured annually on the 5 m sprint as well as for possible explaining variables for 5 m sprint performance development (age, height, body mass, maturity status, lower limb explosive strength). Multilevel analysis was used to obtain a developmental model. Moreover, it was possible to predict sprint performance (5 m) based on chronological age, body size given by height, and lower limb strength performance (p < .05). Significant different developmental patterns were found for elite and sub-elite players, with elite players aged 10–14 being faster. After age 14, no significant differences were found in sprint performance between elite and sub-elite players (p > . 05). Sprint performance is an important characteristic of young female tennis players and seemed to depend on growth and maturation in parallel to physical fitness.

Explosive Strength of Lower Limbs in 10 – 12 Years Old Athletes of Individual Sports

Summary The aim of the study was to determine the levels of lower limb explosive strength of girls in different sport specialization. The sample consisted of 24 girls in aerobic gymnastics (n = 12) and athletic (n = 12) aged 10 to 12 years. To assess the levels of girls’ lower limbs explosive strength, we administered the following tests: countermovement jump test, countermovement jump with free arms test, squat jump test, 10-seconds repetitive jumping test. Testing sessions took place in September 2019. To obtain data about the levels of lower limbs explosive strength, we recorded step height (cm) and duration of the flight phase (s). Data about the lower limbs explosive strength were collected using the Optogait system for optical detection. We applied basic statistical characteristics, namely Student’s t-test and multivariate linear regression. There were no significant differences between girls in aerobic gymnastics and athletics. We recorded better test results in the group of girl’s athletes in the countermovement jump, countermovement jump with free arms and squat jump. In the group of girl’s involved in aerobic gymnastics, we recorded better results in the 10-second repetitive vertical jumping and vertical jump strength. According to the collected data, we may conclude that the training process of the selected girls in terms of explosive strength development is significantly different. Girls involved in aerobic gymnastics showed a higher level of performance in the 10-second vertical jump, which results from the structure of sport specificity.

Effect of Tabata Protocol on Exertion Level and Lower Limb Explosive Strength in Recreational Footballers: An Experimental Study

Effect of Tabata Protocol on Exertion Level and Lower Limb Explosive Strength in Recreational Footballers: An Experimental Study

CORRELATION ANALYSIS OF OLYMPIC-STYLE WEIGHTLIFTING EXERCISES AND VERTICAL JUMPS

ABSTRACTPURPOSE Many types of vertical jumps (VJ) are commonly used to assess the development of the level of explosive strength of lower limbs achieved after a training period. This study is focused on comparing various parameters of different types of VJ with 1 RM in Olympic-style weightlifting, squat and deadlift with an Olympic bar.METHODS Twelve elite weightlifters (men=8; women=4; age 26±4 years, height = 173±8 cm; weight 93±23 kg; weight category from 64 kg to +109 kg) were tested for 1 RM in the following exercises: snatch, clean and jerk, deadlift, squat and variations of VJ on dynamometric plates (Kistler Force Plate). The variations of VJ were: squat jump with the arm swing (SJA) and non-arm swing (SJ), countermovement jump with the arm swing (CMJA) and non-arm swing (CMJ). The parameters compared for each type of VJ were: jump height (m), relative force (% of body weight), relative power (W/kg of body weight) and average power (W). For statistical analysis, the parametric Pearsons correlation coefficient with α=0.05 was used. RESULTS The results show a significant correlation between 1 RM in exercises with an Olympic bar (snatch, clean and jerk, back squat and deadlift) and the CMJ, CMJA, SJ and SJA only in the average power output (W) parameter (p&lt;0.05). The significant correlation coefficients in the average power output (W) were for the CMJA and the snatch r=0.96 r2= 0.92, clean and jerk r=0.96 r2= 0.92, back squat r=0.97 r2= 0.94 and deadlift r=0.93 r2= 0.86; CMJ with hands on the hips and the snatch r=0.93 r2= 0.86, clean and jerk r= 0.93 r2= 0.86, back squat r= 0.95 r2= 0.90 and deadlift r= 0.94 r2= 0.88; for the SJA and the snatch r=0.8 r2= 0.64, clean and jerk r=0.81 r2= 0.65, back squat r=0.82 r2= 0.67 and deadlift r=0.78 r2= 0.60; for the SJ with hands on the hips and the snatch r= 0.76 r2= 0.57, clean and jerk r= 0.75 r2= 0.56, back squat r= 0.77 r2= 0.59 and deadlift r= 0.71 r2= 0.50. Significant correlation coefficients were not found for 1 RM in the snatch, clean and jerk, back squat and deadlift and the CMJ or SJ with and without arm swing in any of the following parameters: jump height (m), relative force (% of body weight), relative power output (W/kg of body weight).CONCLUSION The main finding is that the jump height (m) of the CMJ or SJ with or without arm swing did not correlate significantly with 1 RM in the snatch, clean and jerk, back squat and deadlift. Therefore, jump height measurement can be used as a motivation tool but not to predict maximum strength in Olympic bar exercises, or vice versa. We recommend using the average power output (W) parameter in the CMJ with using arms as a predictor of current performance level in exercises with an Olympic bar for men and women.Key words: snatch, clean and jerk, squat, deadlift, countermovement jump, squat jump

Prediktori fizičke ativnosti u ranoj adolescenciji - doprinos opšte fizičke forme i fizičkog self-koncepta

Vast empirical evidence suggests a high significance of physical activity (PA) for health and well-being. Still, researches show a decline of PA in youth worldwide. Early adolescence is a particularly sensitive period because then children adopt healthy habits and build a positive attitude towards PA. Examining the significance and contribution of potential factors to overall PA in early adolescence is of theoretical and practical relevance. Thus, this study aimed to explore the validity of physical fitness and physical self-concept in the prediction of overall PA in early adolescence, taking into account gender and Body Mass Index (BMI). The sample consisted of 417 primary school students (54.9% boys), the average age 13.6 years (SD=0.73) who participate in regular physical education classes three times per week, each class 45 minutes. Physical self-concept was measured using the Physical Self-Description Questionnaire (PSDQ). To assess everyday physical activity, we used the Physical Activity Questionnaire for Adolescents (PAQ-A). Anthropometric measurements included the body height and bodyweight of the respondents. Physical fitness, i.e., flexibility, muscular strength (abdominal endurance strength and lower-limb explosive strength), and cardiorespiratory endurance were measured using the EUROFIT test battery. Hierarchical regression analysis showed that physical self-concept predicts 35% of the variance of PA over and above gender and dimensions of physical fitness. Significant predictors of physical activity were dimensions of physical self-concept: Physical Activity, Sports Competence, and Endurance. The interaction of Gender and Self Esteem contributed significantly indicating that higher Self Esteem had a significant role in the level of PA only in male adolescents. The main finding is that physical self-concept plays a crucial role in the prediction of the level of overall PA in which early adolescents will be engaged. The results support findings showing that intervention programs aimed to improve PA should encourage positive physical self-concept of adolescents with appropriate content and procedures.

Effect of periodization on the physical capacities of basketball players of a military school

Basketball is a sport modality that imposes important physiological loads on players during competition. The aim of the study was to verify the effect of training with wave periodization on the physical capacities of athletes. Explosive strength of lower limbs; aerobic resistance; maximum strength of upper limb; and resting heart rate (HRrest) at PRE and POST moments of 16 athletes submitted to a 4-month training period were evaluated. The internal training load was monitored by the method proposed by Carl Foster in each training session. Statistically significant differences were observed in VO2max of 50.5± 4.9 vs. 54.0± 6.1 ml/kg/min (p <0.000), in the vertical impulse of 39.1±5.9 cm vs. 44.7±5.9 cm (p <0.000), 10 RM on bench press 40.4± 9.4 vs. 48.0±8.9 kg (p <0.000) and in HRrest 66± 4 vs. 60± 5 bpm (p <0.000). The average internal training load was 751± 249 AU. It was concluded that school basketball athletes submitted to training macrocycle with 4-month wave periodization improve the strength of lower and upper limbs, also presenting positive adaptations in aerobic conditioning.