Lower Body Explosive Strength Research Articles

The effect of concurrent high-intensity interval training and resistance training on the lower body maximal strength and explosive power: A updated systematic review and meta-analysis

BACKGROUND: Endurance training can have a negative impact on strength training and may lead to reduced strength gains, known as the interference effect. However, high-intensity interval training (HIIT) as an endurance training mode may reduce this interference effect. OBJECTIVE: This systematic review and meta-analysis aim to investigate the effects of concurrent HIIT and resistance training (RT) on lower body explosive strength and maximum strength. METHODS: Five electronic databases were searched. Subgroup analyses were performed to assess the effects of HIIT modality, training status, and training duration on strength development following concurrent HIIT and RT. RESULTS: Meta-analysis showed that compared to RT alone, concurrent HIIT and RT will not affect the development of countermovement jump (CMJ) (WMD =-0.17, 95%CI =-1.45 to -1.11) and half squat (WMD =-0.05, 95%CI =-2.42 to 2.32). Further, subgroup analysis revealed that HIIT-running workout was conducive to the development of both CMJ and half squat. Longer training duration was found to be more effective in developing CMJ, while shorter training duration was more suitable for developing half squat. Additionally, athletes showed greater improvement than non-athletes. CONCLUSIONS: Combining HIIT and RT can enhance CMJ and half squat. The results of intervention are moderated by training variables and training status.

Research on the Cultivation of Core Literacy of Physical Education Professionals in Colleges and Universities Based on the Background of Data Mining

Abstract In the context of the data-driven era, it is essential to explore practical ways to cultivate the core literacy of sports professionals in colleges and universities. This study aims to analyze the core literacy of physical education majors in depth by using data mining technology to seek a more scientific and systematic cultivation strategy. The study used the decision tree CART algorithm and the improved Apriori algorithm to analyze the physical fitness data of the students in the School of Physical Education of S University. The CART algorithm clustered the biological fitness data of male and female students, and it was found that male students’ primary physical fitness deficiencies were concentrated in the upper body strength and standing long jump events. In contrast, female students showed deficiencies in endurance and lower body explosive strength. The improved Apriori algorithm reveals the association rules between different physical fitness items, for example, there is a strong association between boys’ 50-meter running performance and pull-up performance. There are apparent differences in the influencing factors of physical fitness between male and female students, which need to be targeted to design training programs. It was found through association rule mining that specific physical testing programs significantly affect students’ physical fitness quality. This study provides a new path for cultivating core quality of physical education professionals based on data mining, which offers scientific basis and practical guidance for physical education in colleges and universities.

Lower limbs strength variations between injured and non-injured professional soccer players.

Due to its physical demands, professional soccer is becoming a real challenge regarding players' exposure to high injury risk. Given its tight correlation with high-intensity actions, muscular strength is a crucial physical characteristic for soccer players. Therefore, the aims of this study are (a) to compare the vertical jumping performance during the season according to the injury profile, and (b) to investigate differences in isokinetic strength performance at the beginning and the end of the season. Twenty-one male professional soccer players (age: 26.0 ± 4.1 years, height: 181.0 ± 6.9 cm, body mass: 73.7 ± 6.9 kg) were assessed in isokinetic strength (Biodex System 4 Pro Dynamometer), and Optojump Next (Microgate, Bolzano, Italy). Isokinetic strength analyses considered the peak torque scores of knee flexors and knee extensors, according to the player's preferred and non-preferred limb. The countermovement and squat jump maximum height were assessed as lower body explosive strength indicators. No significant differences were found when comparing injured and non-injured players in vertical jump and isokinetic strength assessments. However, significant results were found when comparing both groups' initial and final evaluation in isokinetic strength assessment, with both groups significantly improving their performance. Our findings indicate that the overall lower body strength performance was not a discriminant factor between injured and non-injury players. Thus, muscular strength assessment performance increased throughout the season independently of the injury profile. Future research needs to integrate other variables related to sports injuries since they seem to result from multifactorial causes.

Acute Effects of Combined Lower-Body High-Intensity Interval Training and Upper-Body Strength Exercise on Explosive Strength Performance in Naturally Menstruating Women.

We aimed at investigating the acute effects of lower-body high-intensity interval training (HIIT) on upper- and lower-body explosive strength assessed by mean propulsive velocity (MPV) in naturally menstruating women. In addition, we assessed the combination of lower-body HIIT and squat, as well as lower-body HIIT and bench press, on bench press and squat MPV. Thirteen women (age: 23 [2]y, menstrual cycle length: 28.4 [2.0]d) completed 2 training modalities on separate days (separated by 30 [4.2]d) consisting of HIIT followed by lower-body (HIIT + LBS) or upper-body (HIIT + UBS) strength loading. Squat and bench press MPV were assessed before HIIT (T0), after HIIT (T1), after the strength loading (T2), and 24hours postloading (T3). Mixed factorial analysis of variance indicated a significant effect for time in bench press and squat (P < .001) but not for interaction. Pairwise comparison showed that bench press MPV remained unchanged (P = 1.000) at T1 but was reduced at T2 compared with T0 (HIIT + LBS: -8.2% [3.9%], HIIT + UBS: -13.8% [12.1%], P < .001) and T1 (HIIT + LBS: -7.1% [3.2%], HIIT + UBS: -12.7% [8.7%], P < .001). Squat MPV decreased at T1 (HIIT + LBS: -6.0% [8.8%], HIIT + UBS: -4.8% [5.4%], P = .009) and was found to be decreased at T2 compared with T0 in both conditions (HIIT + LBS: -6.9% [3.3%], HIIT + UBS: -7.4% [6.1%], P < .001) but not compared with T1 (P = 1.000). Bench press and squat MPV returned to baseline at T3 compared with T0 (P > .050). Lower- but not upper-body explosive strength was reduced by HIIT. HIIT combined with upper- or lower-body strength loading resulted in a reduction of squat and bench press explosive strength.

Differences in explosive strength values for students of the faculty of physical education and sports (male) according to body mass index levels

Background and Study Aim. Explosive strength/muscular strength is demanded at the level of different body segments and regions in most sports. The purpose of the research: is to identify the differences in the manifestation of explosive force between groups of underweight, normal weight and overweight university students; to determine the associations between the anthropometric parameters and the value of the results in the applied tests.&#x0D; Material and Methods. The investigated group consists of 147 students (men) of the Faculty of Physical Education and Sport, divided into 3 distinct groups for the analysis of the results: underweight (age=20.40±1.18, BMI=17.81±0.93), normal weight (age=20.504±1.671, BMI =22.24±1.67) and overweight (age=22.44±2.24, BMI=28.01±2.74). 7 tests were used to evaluate the explosive strength of the lower body (Vertical Jump Test, Standing Long Jump Test, 3-Hop Test, The multiple 5 bounds test, 30s Lateral double leg hop test, 30s Continuous vertical jumps, Speed Test 10m). A number of 6 tests were used to evaluate the explosive strength of the upper body (Overhand ball throw, Shot put, Overhead Medicine Ball Throw-forward, Overhead Medicine Ball Throw-backward, Medicine ball chest throw, 30s Plyometric Push-Ups).&#x0D; Results. Univariate test results indicate F values associated with significant thresholds at the lower body level (P&lt;0.05) for tests based on horizontal jumps (Standing Long Jump, 3-Hop Test and The multiple 5 bounds test), where underweight and normal weight have the better average scores. At the level of the upper body, the situation is changed (for Shot put and medicine balls throws), where the overweight have the best average values, followed by the normal weight, and the worst results are found for the underweight group (P&lt;0.05). Only for the Overhand ball throw and 30s Plyometric Push-Ups, the superiority of the overweight is not statistically confirmed (P&gt;0.05). Correlation calculation (Pearson values) indicates positive associations between body height and vertical and horizontal jumps (except for those repeated for 30s), but negative associations of BMI and body mass with jump-based tests. However, BMI and body mass are moderately, positively and significantly correlated with throw-based tests (P&lt;0.05).&#x0D; Conclusions. We can state that the classification of students in different BMI categories generates differences in explosive strength values between the 3 studied groups. The comparisons indicate the superiority of underweight and normal weights over overweight in all lower body explosive strength tests. The comparisons indicate also the significant superiority of overweight in the medicine ball and shot put tests over normal and underweight. The obtained results cannot be generalized, due to the small size of the underweight and overweight samples. Further investigations on larger groups of university students being necessary.

The effects of body size and training environment on the physical performance of adolescent basketball players: the INEX study

Background Although adolescent basketballers differ in body size, shape, and composition, less is known about how these factors interact during physical development. Aim We used ontogenetic allometry to identify the optimal body size and shape characteristics associated with physical performance in adolescent basketball players, and investigated the effects of training experience, training volume, maturity status, and club characteristics on physical performance development. Subjects and methods Two hundred and sixty-four male basketballers, from five age-cohorts (11–15 years of age), were followed consecutively over three years. Three physical performance components, anthropometrics, training information, and biological maturation were assessed bi-annually. Longitudinal multiplicative allometric models were developed. Results Players with a physique that had a dominant ectomorphic component performed better in all physical performance components. When adjusting for confounders other than size, the development of running speed was independent of body size. Players advanced in maturation were physically fitter. Training data had no significant effect on developmental trajectories of running speed or lower body explosive strength. Club characteristics had no significant association with any physical performance trajectories. Conclusion Leaner players have advantages in physical performance and individual characteristics play an important role, over and beyond club structure, in developing physical performance.

Strength and conditioning programs in youth athletes: a systematic review

Purpose.The relationship between strength, power, and sports performance may have long-term effects on the development pathways of youth athletes. This study systematically reviewed the current evidence of strength and conditioning interventions among youngsters in competitive sports.Methods.The research was conducted following the Preferred Reporting Items for Systematic and Meta-Analyses (PRISMA) 2020 guidelines.Results.A total of 415 articles were identified, and 20 remained for analysis. All studies reported resistance training (RT) and/or plyometric training (PT) interventions as beneficial to improving youngsters’ overall physical fitness. The lower-body explosive strength, speed, and agility improvements were more evident in training plans that combined heavy RT and PT programs. The training frequency of twice a week was sufficient to induce strength gains. The results indicate that strength and conditioning programs positively influence sport-specific skills performance.Conclusions.PT and RT should not be implemented as single exercise interventions but as complementary programs to optimise physical and game performance. This study contributes to creating awareness among sports agents and coaches for integrating planned strength and conditioning programs with qualified instruction at least two times per week to improve young athletes’ physical development.

BANGLADESHI AND INDIAN YOUTH ATHLETES DIFFER IN STRENGTH AND ENDURANCE

The purpose of the research was to investigate the health-related physical fitness of youth athletes from Bangladesh and India. The forty athletes from each country, Bangladesh (n=40) and India (n=40) were chosen using a simple random sampling method. The researchers selected Bangladeshi athletes from the Jashore district in Bangladesh and Indian athletes from the Murshidabad and Birbhum districts of West Bengal, India. Those who competed in at least one district-level competition were included in the study. For the study, the researchers chose male athletes between the ages of 17 and 21 years. The study included lower body explosive strength in the standing broad jump test, upper body muscular strength in the pull-up test and cardio-respiratory endurance in the cooper test as variables. The data was analysed using descriptive and inferential statistics (independent t-test), with the significance level set at 0.05. An independent sample t-test shows that Bangladeshi and Indian youth athletes standing broad jump t(78) = 2.10, sig. = 0.039; pull-ups t(78) = 1.68, sig. = 0.099; cooper test t(78) = 2.34, sig. = 0.022 respectively. The findings revealed a substantial difference in leg explosive strength and cardio-respiratory endurance, but no substantial difference in upper body muscular strength between Bangladeshi and Indian youth athletes.

Acute Effects of High-Intensity Interval Running on Lower-Body and Upper-Body Explosive Strength and Throwing Velocity in Handball Players.

Seipp, D, Feuerbacher, JF, Jacobs, MW, Dragutinovic, B, and Schumann, M. Acute effects of high-intensity interval running on lower-body and upper-body explosive strength and throwing velocity in handball players. J Strength Cond Res 36(11): 3167-3172, 2022-The purpose of this study was to determine the acute effects of handball-specific high-intensity interval training (HIIT) on explosive strength and throwing velocity, after varying periods of recovery. Fourteen highly trained male handball players (age: 25.4 (26.2 ± 4.2) performed HIIT consisting of repeated 15-second shuttle runs at 90% of final running speed (V IFT ) to exhaustion . Upper-body and lower-body explosive strength and throwing velocities were measured before and immediately after HIIT, as well as after 6 hours. These tests included 3 repetitions of both bench press and squat exercise at 60% of the 1 repetition maximum (1RM) as well as 3 repetitions of the set shot without run up and jump shot, respectively. Explosive squat performance was significantly reduced at post (-5.48%, p = 0.026) but not at 6 h (-0.24%, p = 1.000). Explosive bench press performance remained statistically unaltered at post (0.32%, p = 1.000) and at 6 hour (1.96%, p = 1.000). This was also observed in the subsequent throws both immediately after (-0.60%, p = 1.000) (-0.31%, p = 1.000) and at 6 h (-1.58%, p = 1.000) (1.51%, p = 0.647). Our data show a reduction in explosive strength of the lower but not upper extremities when preceded by running HIIT. Since throwing velocity was not affected by intense lower-body exercise, combining lower-body HIIT and throwing practice may be of no concern in highly trained handball players.

Norm Values of Muscular Strength Across the Life Span in a Healthy Swiss Population: The COmPLETE Study.

Grip strength is used to estimate whole-body strength for health surveillance purposes. Explosive strength is considered important, yet economic measures able to detect early deterioration of neuromuscular capabilities are lacking. Whether handgrip maximum rate of force development (GRFD) or whole-body strength tests are better predictors of lower body power than handgrip maximum strength (GFmax) and their trajectories throughout the life span are unknown. GRFD should be more closely related to lower body power than GFmax, and its trajectories over the life span should more closely follow that of lower body power. Cross-sectional. Level 2b. A total of 613 healthy participants aged 20 to 91 years were tested for countermovement jump peak power, GFmax, handgrip rate of force development, and midthigh pull peak force (MTP). Cubic splines and linear models were built for age trajectories, generalized additive models for quintile curves, and linear regression was used to assess predictive quality. Peak power (Pmax) declined linearly to 60% of young adult level, with GRFD, GFmax, and MTP remaining stable up to age 50 years and then declining more sharply to 52% to 71% of young adult levels. Trajectories were similar for male and female participants. GRFD (β = 0.17) and MTP (β = 0.08) were worse predictors of Pmax than GFmax (β = 0.24) in models adjusted for age, sex, lean body mass, and vigorous physical activity levels. GRFD was not superior to maximum strength in predicting lower body power. For health surveillance purposes, it therefore appears that GFmax tests are more economical and equally good predictors of lower body explosive strength at older age. The data provided can be used as norm values for healthy subjects. Incorporating countermovement jump testing for early detection of declines in explosive capabilities might be advised.

Physical Development Differences between Professional Soccer Players from Different Competitive Levels

In soccer, physical development is crucial for developing optimal performance. This study aimed to assess and compare the physical development of elite and non-elite professional soccer players. Seventy-eight male professional football players divided into four competitive levels participated in this study: the elite group (EG), the non-elite group A (NEG-A), the non-elite group B (NEG-B), and the under 23 group (U23). Body composition, static strength, lower-body explosive strength, flexibility, and balance were assessed. No significant statistical differences between elite and non-elite players were seen in body composition parameters. However, the EG performed better in static strength, lower-body explosive strength, flexibility, and balance, even after adjusting for the effects of chronological age. The analysis showed that the competitive level (group) explained 25% to 29% of the variance observed in the lower-body explosive strength tasks. Sports staff and coaches in different age categories or competitive levels should include specific lower-body explosive strength content during soccer training to promote players’ long-term development towards the elite level.

Predicting lower body explosive strength using hand grip dynamometer strength test

Problem statement: Numerous fitness tests are usually administered to determine either muscular strength or cardiovascular endurance. Even though an ample number of tests exist to measure upper body muscular endurance and lower body maximal muscular strength, a single test that assesses both could be beneficial in some circumstances. Purpose: The purpose of this study was to determine if a hand-grip dynamometer strength test is a valid predictor of lower body explosive strength. Methods: Participants included 164 college students including both genders included boys = 83, (age 20.72±2.82 yrs., height 170.28±5.48 cm, weight 62.01±9.55 kg) and girls = 81, (age 20.64±2.74 yrs, height 159.30±5.68 cm, weight 55.71±8.14 kg). Subjects performed the standing broad jump (SBJ) for lower body explosive strength. Subjects performed 3 trials of the dominant hand grip strength (dHGS) test, after which the maximum value was recorded. Pearson bivariate correlation analyses were used to determine relationships between measures. Simple linear regression with enter method was performed to predict variation in lower body explosive strength through the hand grip dynamometer strength test. Results: Significant correlations were found between dHGS and SBJ (r = .802, p

Acute Effects of Concurrent High-Intensity Interval Cycling and Bench-Press Loading on Upper- and Lower-Body Explosive Strength Performance.

This study examined the acute effects of lower-body high-intensity interval loading (HIIT) on explosive upper- and lower-body strength, as well as the combined effect of HIIT and bench-press loading versus HIIT and squat loading on the explosive upper- and lower-body strength. Fifteen physically active men completed 2 sessions consisting of HIIT (4 × 4min cycling at 80% of peak power output) immediately followed by lower- (HIIT + LBS) or upper-body (HIIT + UBS) strength loading (3 × 5 + 3 × 3 repetitions at 80% 1-repetition maximum [ie,6 sets in total]) in a randomized order. Squat and bench-press mean propulsive velocity (MPV) was assessed before HIIT (T0), immediately after HIIT (T1), immediately after the strength loading (T2), and 24hours after the experimental session (T3). Squat MPV decreased to a similar magnitude at T1 in HIIT + LBS (-5.3% [7.6%], P = .117, g = .597) and HIIT + UBS (-5.7% [6.9%], P = .016, g = .484), while bench press remained unchanged (-1.4% [4.7%], P = 1.000, g = .152, and -1.0% [7.0%], P = 1.000, g = .113, respectively). Both squat and bench-press MPV were statistically reduced at T2 compared to T0 (HIIT + LBS: -7.5% [7.8%], P = .016, g = .847, and -6.8% [4.6%], P < .001, g = .724; HIIT + UBS: -3.9% [3.8%], P = .007, g = .359, and -15.5% [6.7%], P < .001, d = 1.879). Bench-press MPV at T2 was significantly lower in HIIT + UBS when compared to HIIT + LBS (P = .002, d = 1.219). These findings indicate lower- but not upper-body explosive strength to be acutely reduced by preceding lower-body HIIT. However, lower-body HIIT combined with either upper- or lower-body strength loading resulted in a similar acute reduction of both squat and bench-press explosive strength.

Leg Dominance and OSB12 Kick Start Performance in Young Competitive Swimmers

The purpose of this study was to examine differences in starting and kick-plate positions, pointing to an effect on kick-start performance with the dominant and non-dominant feet placed on the front edge of the OSB12 starting block. The sample included 20 female competitive swimmers whose average age was 16.1 ± 0.6 years. To assess swimmers’ lower body explosive strength and determine leg dominance, a triple hop distance test was administered. We determined the swimmers’ preferred starting position on a starting block in terms of the kick-plate setting and body position on the starting block. The results of our study demonstrate the importance of leg dominance and positioning on the OSB12 starting block. After the preferred starting position was determined, the optimal position for the kick start was selected. When the dominant leg was placed on the front edge of the starting block (p < 0.05; Cohen’s d—large effect), swimmers produced shorter block times and times to 2 and 5 m. For most of the tested swimmers, the optimal basic position on the starting block included neutral- and rear-weighted positions with the kick plate set to positions 3–4 and the right leg placed on the front edge of the OSB12 starting block.

Birth weight and breastfeeding are differentially associated with physical fitness components.

The study purpose was to assess the impact of birth weight and breastfeeding duration on physical fitness components. Study participants were 985 adolescents boys and 1246 girls (12.5-17.5 years) participating in the HELENA study. Standardised physical fitness procedures included: cardio-respiratory fitness, flexibility, upper body muscular strength, and lower body explosive strength. Birth weight and breastfeeding duration were assessed by parents' questionnaire. Associations between neonatal data and physical fitness were investigated using linear mixed models. Significant associations between body muscular strength, and breastfeeding duration were observed in the unadjusted analyses for boys. When adjusting for potential confounding factors (z-score body mass index, fat-free mass, fat mass), only lower body muscular strength, by standing broad jump-a proxy measure of muscular explosivity- was positively associated with breastfeeding duration. Furthermore, significant associations were observed between upper body muscular strength (by hand grip),-a proxy measure of muscular power-in boys as well as in girls. Birth weight and breastfeeding duration have different effects on muscular strength components. The present results suggest that birth weight positively influences the development of muscular power, while breastfeeding duration positively influences muscular explosivity.

Effect of Inter-Repetition Rest vs. Traditional Strength Training on Lower Body Strength, Rate of Force Development, and Muscle Architecture

The purpose of the study was to investigate the effect of seven weeks inter-repetition rest vs. traditional strength training on lower body strength, rate of force development (RFD), and vastus lateralis (VL) muscle architecture. Sixteen male participants were assigned into two groups: the inter-repetition rest (IRRG) and the traditional (TG) group. Both groups performed the leg press exercise with four sets of six maximum repetitions (RM) for two training sessions per week. IRRG added a 20 s inter-repetition rest period between single repetitions. Before and after the training period, 1-RM in leg press, isometric leg press RFD, and peak force (PF), VL muscle architecture, vastus intermedius (VI) thickness, and quadriceps’ cross sectional area (CSA) with ultrasonography, were measured. Two way ANOVA for repeated measures was used for statistics. One-RM strength increased similarly for both groups (p &lt; 0.05), while percentage increases in RFD were greater for IRRG compared to TG (p &lt; 0.05). Isometric PF was increased similarly for both groups (p &lt; 0.05). VL and VI thickness as well as CSA of the quadriceps increased similarly in both groups, while VL fascicle length increased more following IRRG compared to TG (IRRG: 4.8 ± 6.1% vs. TG: −3.9 ± 5.4%, p = 0.001). These results suggest that 20 s inter-repetition rest during strength training may effectively increase lower body explosive strength and muscle fascicle length without compromising muscle hypertrophy.

The impact of the mechanical whole-body vibration experienced during military land transit on the physical attributes underpinning dismounted combatant physical performance: A randomised controlled trial

ObjectivesThe aim of this randomised controlled trial was to explore the impact of the mechanical WBV experienced during simulated military land transit on the physical attributes that underpin tasks performed by dismounted combatants. DesignThis study used a parallel group randomised control trial design. MethodsSixty participants were randomly assigned to one of four, 2-h laboratory-based simulations (restricted posture, sealed road, cross country or a control condition). A smaller sample of 16 Australian Defence Force infantry personnel served as a validation group and were exposed to the same conditions. Neither the restricted posture nor the control conditions were exposed to any WBV, but the former were secured in place using the built-in seat harness. Prior to, and following the assigned condition, participants performed a series of battlefield relevant physical performance tests including; drop jump, 20-m sprint, reactive agility, arm-hand steadiness, isometric mid-thigh pull, and sit-and-reach. ResultsMedium decreases in the drop jump were observed for both the sealed road (effect size [ES]=0.53) and cross-country (ES=0.97) simulation conditions indicating a decrease in performance of the jump phase. A large decrease in 20-m sprint performance was observed in both the sealed road (ES=1.37) and cross-country (ES=0.88) exposure conditions. Additionally, a large decrease in 20-m sprint performance was observed for the restricted posture (ES=1.02) exposure condition. ConclusionsThese findings indicate that exposure to WBV experienced during motorised land transit has a negative influence on aspects of lower body explosive strength.

Effects of moderate to vigorous intensity interval exercise program on fitness and fatness in 11-and 12-years-old schoolchildren

Introduction: there is growing evidence of concern for values in terms of physical condition and body composition alarming that place school child at risk parameters in physical health. Numerous investigations relate physical activity with improvement in physical condition and body composition. Objective: to analyze the effects of a sub-maximal intensity interval exercise program on physical condition (upper body isometric strength in both hands, lower body explosive strength, velocity-agility and cardiorespiratory fitness) and body composition (body mass index, % of body fat, waist circumference and waist/height index), all of them related to health, in schoolchildren of 11 and 12 years. Methods: an intervention was developed in which an experimental group participated and another control group with 28 schoolchildren each. Happened over 8 weeks, with sessions of total 30 minutes before the start of the academic activity 3 days per week. Different intervallic games were made with motor, cognitive and coordination challenges; with a moderate-vigorous intensity (70 %-80 % of maximum heart rate). The registration in physical condition and body composition was made through the ALPHA Battery. Results: significant improvements in isometric strength with both hands and a reduction in waist circumference and waist/height index. Conclusions: the results show significant improvements in indicators of fitness and fatness, however, it requires a long-term intervention to know if the other improvements achieved in the analyzed indicators are significant over time.

Association between Weight Status and Physical Fitness in Chinese Mainland Children and Adolescents: A Cross-Sectional Study.

Background: The increasing prevalence of obesity among children and adolescents is a major public health challenge worldwide. This study examined the relationship between physical fitness and BMI spanning the range from underweight to obese among Chinese mainland children and adolescents. Methods: Participants were 22,681 children and adolescents (11,300 boys and 11,381 girls) aged 10–18 years from the Chinese mainland. Weight status was classified as underweight, normal weight, overweight, and obese using WHO 2007 standards. Physical fitness parameters such as cardiorespiratory fitness (VO2max), lower body explosive strength (standing broad jump), upper body explosive strength (handgrip strength), abdominal muscular endurance (sit-ups in 30 s), flexibility (sit-and-reach), and agility (repeat bestride (20 s)) were assessed. Results: There was a significant association between weight status categories and physical fitness in all age groups and sex (plinear < 0.001, pquadratic < 0.001). Underweight adolescents performed better in lower limb strength, flexibility, agility, and cardiorespiratory fitness than their obese peers, but worse in upper limb strength. Underweight boys aged 10–11 and 12–13 years and girls aged 10–11 years showed significantly (p < 0.05) high odds of meeting a low physical fitness index. Obese adolescents have high odds of meeting a low physical fitness index with age. Conclusion: The present study showed a nonlinear relationship between weight status and physical fitness. Children and adolescents who were classified as underweight or obese had poorer physical fitness than their normal-weight peers.

Effect of the French Contrast Method on Explosive Strength and Kinematic Parameters of the Triple Jump Among Female College Athletes.

There are resistance training methods that result in strength, others that enhance hypertrophy and others that stimulate power. The training modality of contrast provides all of these benefits in one session. The concept of French Contrast training is based on a combination of complex and contrast methods. The idea is to use four exercises to induce physiological responses of the athlete and train along the force-speed curve. The primary purpose of the study was to investigate the impact of the French Contrast Method on explosive strength and kinematic parameters of the triple jump among female college athletes. Ten female college athletes from the Helwan University’s track and field team participated in this study. Participants were assessed before and after an 8-week training program for upper and lower body explosive strength. No significant differences were observed in anthropometric characteristics. Explosive strength variables (Sargent jump test, countermovement jump, and seated medicine ball throw) increased significantly and kinematic parameters of the triple jump improved. The results indicated that eight weeks of the French Contrast training can improve both explosive strength and kinematic parameters of the triple jump.