Effect of maturation level on normative specific-agility performance metrics and their fitness predictors in soccer players aged 11-18 years.

BACKGROUND: In sports sciences, normative data serve as standards for specific physical performance attributes, enhancing talent identification within a specific population. The aim of this study was to provide standard data for Agility-15 m, Ball-15 m tests, and skill index, considering maturation level, specifically age at peak height velocity (PHV). The study also investigated the relationship between relative performances in these tests and anthropometrics, jumping (squat jump [SJ], countermovement jump [CMJ]), and sprinting abilities (S-5 m, S-10 m, S-20 m, S-30 m) in young soccer players. METHODS: The study involved 647 soccer players aged 11-18 years, categorized into three groups: pre-PHV, circum-PHV, and post-PHV. Statistical analysis was conducted using analysis of variance and Bonferroni post hoc testing to detect variations among maturation groups, and Pearson's correlation test to examine the relationship between factors. RESULTS: Agility-15 m and ball-15 m performances among maturity groups showed significant differences (p < 0.01). Significant correlations were identified in pre-PHV group, between lower limb length and Agility-15 m (r=-0.23, p < 0.05) and between height and Ball-15 m (r=-0.23, p < 0.05). In post-PHV group, there was a correlation between body fat percentage (BF %) and Agility-15 m (r = 0.17, p < 0.05) and Ball-15 m (r = 0.21, p < 0.05). In all maturity groups, there were significant correlations between agility and sprint tests (S-5 m, S-10 m, S-20 m, and S-30 m) and muscle power (SJ and CMJ). CONCLUSION: The study revealed that both speed and lower limb power significantly influence agility in young soccer players, providing valuable insights for coaches and practitioners to create tailored training plans and interventions for different age groups and maturity levels.

Allometric Association between Six-Minute Walk Distance and Both Body Size and Shape in Young Obese Girls.

BACKGROUND: The 6-min walk test (6MWT) provides information regarding functional capacity, response to therapy and prognosis in a variety of chronic cardiovascular disorders. Variability in body size and composition, particularly in obese people, confounds the six-minute covered distance (6MWD). The aim of the present study was to adopt allometric models to identify the most appropriate body size/shape; i.e., body mass (BM), body height (BH), body mass index (BMI) and estimated fat-free mass (FFM); associated with the 6MWD in 190 young girls with obesity. METHODS: Nonlinear allometric modeling was used to calculate common body size exponents for BM, BH, BMI and FFM. In a validation sample of 35 age-matched obese girls, these allometric exponents were used prospectively. RESULTS: The point estimates for the size exponents (95% confidence interval) from the separate allometric models were: BM 0.23 (0.19-0.27), BH 0.91 (0.78-1.03), BMI 0.33 (0.23-0.44) and FFM 0.28 (0.24-0.33). The presence of significant residual size correlations for 6MWD/BH-0.91 indicates that the influence of body size was not correctly partitioned out. In the validation group, the correlations between 6MWD BM-b and BM, 6MWD BMI-b and BMI, and 6MWD FFM-b and FFM using the established exponents were not statistically different from zero (r = 0.01), implying that participants in the allometric investigation were not penalized based on their BM, BMI, or FFM. CONCLUSION: We conclude that BM, BMI, BH and FFM, as indicators of body size/shape, are the most valid allometric denominators for the scaling of 6MWD in a group of young girls with obesity.

Fatigue score as a promising complementary training monitoring tool: a pilot study in elite rugby sevens players.

The aim of this study was to compare physical and hormonal responses of seventeen elite rugby sevens players over a 6-week intense training block (IT) and a consecutive 2-week tapering period (TAP), using a fatigue cut-off score of 20 as a potential moderating variable. Training was monitored by daily training load (TL) and strain (TS) (using the session rating of perceived exertion [sRPE]) and also the weekly total score of fatigue (TSF; 8-item questionnaire tool). Testing and 24 h urinary cortisol (CL), cortisone (CN), adrenaline (AD) and noradrenalin (NAD) concentrations were also analysed before (T0) and after IT (T1) and after the TAP (T2). Players were assigned to group 1 with a TSF above 20 (G1 > 20, n = 9) and group 2 with a TSF below 20 (G2 < 20, n = 8) according to the French Society for Sports Medicine guidelines. TSF (effect size [ES] from 1.17 to 1.75), TL (ES from 0.81 to 1.06) and TS (ES from 1.23 to 1.40) were higher in G1 > 20 than in G2 < 20 over IT. Likewise, performance standards (ES from 1.58 to 2.61) and AD levels were lower (ES = 3.20), whereas CL and CL/CN ratio (ES from 1.60 to 3.47) were higher in G1 > 20 than in G2 < 20. After the TAP, TSF, TL and TS returned to baseline values for both groups, with an increase in performance standards and normalization in hormone levels. We suggest that a TSF greater than or equal to 20 could be considered as a fatigue threshold generating hormone disturbance and performance decrement, making it a potentially useful preventive and complementary training monitoring tool.

COVID-19 Lockdown: A Global Study Investigating the Effect of Athletes' Sport Classification and Sex on Training Practices.

PURPOSE: To investigate differences in athletes' knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. METHODS: Athletes (12,526; 66% male; 142 countries) completed an online survey (May-July 2020) assessing knowledge, beliefs, and practices toward training. Sports were classified as team sports (45%), endurance (20%), power/technical (10%), combat (9%), aquatic (6%), recreational (4%), racquet (3%), precision (2%), parasports (1%), and others (1%). Further analysis by sex was performed. RESULTS: During lockdown, athletes practiced body-weight-based exercises routinely (67% females and 64% males), ranging from 50% (precision) to 78% (parasports). More sport-specific technical skills were performed in combat, parasports, and precision (∼50%) than other sports (∼35%). Most athletes (range: 50% [parasports] to 75% [endurance]) performed cardiorespiratory training (trivial sex differences). Compared to prelockdown, perceived training intensity was reduced by 29% to 41%, depending on sport (largest decline: ∼38% in team sports, unaffected by sex). Some athletes (range: 7%-49%) maintained their training intensity for strength, endurance, speed, plyometric, change-of-direction, and technical training. Athletes who previously trained ≥5 sessions per week reduced their volume (range: 18%-28%) during lockdown. The proportion of athletes (81%) training ≥60 min/session reduced by 31% to 43% during lockdown. Males and females had comparable moderate levels of training knowledge (56% vs 58%) and beliefs/attitudes (54% vs 56%). CONCLUSIONS: Changes in athletes' training practices were sport-specific, with few or no sex differences. Team-based sports were generally more susceptible to changes than individual sports. Policy makers should provide athletes with specific training arrangements and educational resources to facilitate remote and/or home-based training during lockdown-type events.

Training During the COVID-19 Lockdown: Knowledge, Beliefs, and Practices of 12,526 Athletes from 142 Countries and Six Continents.

OBJECTIVE: Our objective was to explore the training-related knowledge, beliefs, and practices of athletes and the influence of lockdowns in response to the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Athletes (n = 12,526, comprising 13% world class, 21% international, 36% national, 24% state, and 6% recreational) completed an online survey that was available from 17 May to 5 July 2020 and explored their training behaviors (training knowledge, beliefs/attitudes, and practices), including specific questions on their training intensity, frequency, and session duration before and during lockdown (March-June 2020). RESULTS: Overall, 85% of athletes wanted to "maintain training," and 79% disagreed with the statement that it is "okay to not train during lockdown," with a greater prevalence for both in higher-level athletes. In total, 60% of athletes considered "coaching by correspondence (remote coaching)" to be sufficient (highest amongst world-class athletes). During lockdown, < 40% were able to maintain sport-specific training (e.g., long endurance [39%], interval training [35%], weightlifting [33%], plyometric exercise [30%]) at pre-lockdown levels (higher among world-class, international, and national athletes), with most (83%) training for "general fitness and health maintenance" during lockdown. Athletes trained alone (80%) and focused on bodyweight (65%) and cardiovascular (59%) exercise/training during lockdown. Compared with before lockdown, most athletes reported reduced training frequency (from between five and seven sessions per week to four or fewer), shorter training sessions (from ≥ 60 to < 60 min), and lower sport-specific intensity (~ 38% reduction), irrespective of athlete classification. CONCLUSIONS: COVID-19-related lockdowns saw marked reductions in athletic training specificity, intensity, frequency, and duration, with notable within-sample differences (by athlete classification). Higher classification athletes had the strongest desire to "maintain" training and the greatest opposition to "not training" during lockdowns. These higher classification athletes retained training specificity to a greater degree than others, probably because of preferential access to limited training resources. More higher classification athletes considered "coaching by correspondence" as sufficient than did lower classification athletes. These lockdown-mediated changes in training were not conducive to maintenance or progression of athletes' physical capacities and were also likely detrimental to athletes' mental health. These data can be used by policy makers, athletes, and their multidisciplinary teams to modulate their practice, with a degree of individualization, in the current and continued pandemic-related scenario. Furthermore, the data may drive training-related educational resources for athletes and their multidisciplinary teams. Such upskilling would provide athletes with evidence to inform their training modifications in response to germane situations (e.g., COVID related, injury, and illness).

Six-minute walk distance equation in children and adolescents with obesity.

AIM: To develop a 6-minute walk-distance (6MWD) reference equation for children and adolescents with obesity, and to assess its determinant factors. METHODS: A cross-sectional study using mixed linear and multiple regression models was conducted in 497 children (235 girls and 262 boys) aged 6-18 years with a body mass index (BMI) greater than 97th percentile. Anthropometrics and a 6-minute walk test (6MWT) were performed. RESULTS: Mean 6MWD was 547 ± 86 m for girls and 575 ± 96 m for boys, which averaged ~80% of a reference normal-weight population matched for age and ethnicity. Age, weight and BMI were positively correlated with 6MWD whereas waist and hip circumferences (WC and HC, respectively) were negatively correlated with 6MWD for both genders. The combination of age, height, BMI and HC explained 69% of the 6MWD variability in the equation for the whole population. Moreover, the combination of age, height, HC as well as the combination of age, height, BMI and WC explained 67% and 75% of the variability in the girls' and boys' equations, respectively. CONCLUSION: This 6MWD reference equation, which was influenced by abdominal obesity markers in a gender-specific way, extends and enhances scientific knowledge and provides useful predictive tools for the care of obese children.

Normative Data and Physical Determinants of Multiple Sprint Sets in Young Soccer Players Aged 11-18 Years: Effect of Maturity Status.

Selmi, MA, Sassi, RH, Yahmed, MH, Giannini, S, Perroni, F, and Elloumi, M. Normative data and physical determinants of multiple sprint sets in young soccer players aged 11-18 years: Effect of maturity status. J Strength Cond Res 34(2): 506-515, 2020-The aims of the study were: (a) to establish normative data for repeated-sprint sets (RSS) test based on the maturity status (age at peak height velocity [PHV]) and (2) to investigate the relationship between anthropometrical variables (stature, sitting height, body mass, and body fat percentage), RSS (2 × 5 × 20 m with 15-second recovery between sprints and 1-minute recovery between sets), and fitness tests {squat jump, countermovement jump, standing long jump, standing triple jump, 5-jump test, and 20-m shuttle run (multistage shuttle run test [MSRT])}. Young male soccer players (n = 262; age: 14.5 ± 2.9 years) were evaluated and classified into 4 groups according to their maturity status: pre-PHV, circum-PHV1, circum-PHV2, post-PHV. An analysis of variance and Bonferroni post hoc were used to determine maturity group differences (p ≤ 0.05), whereas Pearson's correlation was used between variables. Repeated-sprint sets' indices (sum of sprint times [SST] and best sprint time [BST]) were significantly different between the maturity groups. Significant correlations between SST with body mass (from -0.73 to -0.33) and MSRT (from -0.49 to -0.30) among each maturity group were found. With the different maturity groups, correlations between SST (s), BST (s), and vertical jump (cm) (r = -0.63 to -0.25 and r = -0.68 to -0.23) and horizontal jump (m) (r = -0.70 to -0.38 and r = -0.63 to -0.43) were observed. Repeated-sprint sets' values improve during maturation of young soccer players and the correlations between RSS and fitness tests vary through the maturity groups. This information could be useful for the coach to identify talent and to prescribe specific physical training to improve performance.

A preliminary validation of the Arabic version of the "Profile of Emotional Competence" questionnaire among Tunisian adolescent athletes and nonathletes: insights and implications for sports psychology.

BACKGROUND: Emotional intelligence refers to how individuals deal with intrapersonal or interpersonal emotional information and how a subject identifies, expresses, understands, regulates, and uses his/her own emotions or those of others. The purpose of the present study was to validate the Arabic version of the "Profile of Emotional Competence" (PEC) questionnaire. METHODS: A sample of 285 Tunisian participants (153 men and 132 women) was recruited, age range: 12-18 years (15.2±2.4 years). The participants were prospectively classified into the following two groups: athletes (n=101) and nonathletes (n=184). RESULTS: Findings of the present study indicated that the Arabic version of the PEC questionnaire has good psychometric properties. The Cronbach's a suggested that all subscales had adequate internal consistency. Test-retest reliability was excellent. The correlations between interpersonal and intrapersonal subscales were low to moderate (from 0.37 to 0.59), except for the regulation interpersonal, utilization interpersonal, and utilization intrapersonal subscales, which showed negligible correlations with the other subscales. The two-factor solution (interpersonal and intrapersonal competence models) accounted for 62.1% of variance. All subscales loaded on the expected factor, except for the utilization intrapersonal and regulation interpersonal subscales, which did not yield a satisfactory loading. Age and athletes' status impacted on all the PEC dimensions, except for some subscales. CONCLUSION: Finally, psychologists and practitioners in the Arab world could use the PEC questionnaire as a valid and reliable instrument for planning ad hoc interventions.

Data concerning the psychometric properties of the "Profile of Emotional Competence" questionnaire administered to a sample of athletes and non-athletes.

Emotional Intelligence (EI) can be defined as an "ability to monitor one's own and others' feelings and emotions, to discriminate among them and to use this information to guide one's thinking and actions" (Salovey and Mayer, 1990) [1]. As such EI plays a major role in sport sciences. Studies conducted so far have shown contrasting findings. The paper contains data concerning the psychometric properties of the "Profile of Emotional Competence" questionnaire administered to a sample of 479 subjects (239 athletes, 240 non-athletes, age ranging from 12 to 18 years old, 239 men, and 240 women) in order: i) to explore EI between athletes and non-athletes students and ii) to examine differences in EI of young participants in terms of gender and age.

Changes of the psychophysical state and feeling of wellness of professional soccer players during pre-season and in-season periods.

Perceived changes due to training monotony, strain, sleep, stress, fatigue, muscle soreness and the influence of specific training sessions on the affective valence were explored in professional soccer players. Seventeen players completed the Hooper questionnaire, the ratings of perceived exertion and feeling scale (FS) every training/match day before and during the soccer season. Higher players' training loads were recorded during pre-season when compared with in-season period (2558.1 ± 262.4 vs. 1642.8 ± 169.3 a.u., p < 0.01; respectively). The ratings of sleep, stress, fatigue and muscle soreness in pre-season were higher than those observed during in-season (p < 0.01) whereas the feeling score was lower (p < 0.01). Furthermore, training sessions, including technical/tactical work, induced an improved feeling score but linked with a lower training load when compared with sessions focus on physical emphasis (p < 0.01). Pre-season period of training induces a significantly more strenuous and exhausting demands on professional soccer players compared with the in-season period at the elite level.

Jumping improves lower limbs bone mass and lean mass in elite jumpers.

BACKGROUND: The present study was designed to examine the influence of extreme impact loading induced by jump training on bone mineral density (BMD) and bone mineral content (BMC) in high level jumpers. METHODS: Forty boys volunteered for the study aged 20 to 21 years. They were 22 high level jumpers and 18 controls. Bone mass and body composition measurements were performed by dual-energy X-ray absorptiometry, in the total body and at different sites. RESULTS: The results showed that BMC, BMD, bone area, and lean mass (P<0.0001) were significantly higher in the jumpers compared to the controls. A strong positive correlation was found between lean mass and bone parameters (BMC at the right femur, r=0.80; P<0.01). The values of the same correlation were weak in the control group. In addition, the effects of the regular practice of jumping on the BMD, BMC, and bone area were more pronounced in the lower limbs (P<0.01). These adaptations were site-specific, with increased bone mass at the lower limbs (P<0.01), especially at the legs, right and left leg (LRL) (P<0.05). It appears that the time dedicated to this activity may be account for the difference between jumpers and controls. CONCLUSIONS: The practice of high level jump starting at pubertal age generates an increase and an acquisition of the bone mass in males. This adaptation is further enhanced by the times dedicated for this activity. Therefore, it would be interesting to program jumping activities daily to conserve bone mineral and to prevent osteopenia.

Physical and anthropometric changes during pre- and in-season in professional soccer players.

BACKGROUND: The purpose of this study was to examine the changes in anthropometric and physical fitness characteristics in professional soccer players at the beginning of the season, after preseason camp and during in-season. METHODS: Seventeen players were evaluated on three different periods (June: T0, August: T1 and December: T2). Each evaluation consisted of anthropometric measurements (body mass, height, and body fat) and physical fitness tests (counter movement jump [CMJ], counter movement jump with arm (CMJA), 10-m sprint, 30-m sprint and maximal aerobic speed [MAS]). RESULTS: Comparatively with T0, all physical performances achieved in T1 were significantly improved (MAS: P<0.01, 10-m sprint: P<0.05, 30-m sprint: P<0.05, CMJ: P<0.01, and CMJA: P<0.05). The decrease in training load during in-season is associated by significant decrement in MAS (P<0.05) and preserved performances in 10 (P=0.85) and 30-m sprint (P=0.99), CMJ (P=0.34) and CMJA (P=0.87) completed in T2 comparatively with T1. Physical fitness performances achieved in T2 remain higher than that obtained in T0 (MAS: P<0.01, 10-m sprint: P<0.01, 30-m sprint: P<0.05 and CMJ: P<0.05) and remain similar for CMJA (P=0.13). No significant changes were observed in anthropometric measurements throughout the study. CONCLUSIONS: The main finding of this study was that a greater training load accomplished during preseason could lead to an improvement in the physical fitness during in-season in professional soccer players. We suggest that this higher training load meets the needed required for the professional soccer although the training loads are declined during in-season.

Reference values of vertical jumping performances in healthy Tunisian adolescent.

BACKGROUND: The assessment of normal values of muscle strength can be determined for the health outcome of adolescents, especially those who are living in a developing country. AIMS: The purpose of this study is to identify the relationship between anthropometric variables and vertical jumping performances. The jump height and the average of power were measured to establish reference values of vertical jumping parameters in Tunisian healthy adolescents aged 13-19 in both sexes. SUBJECTS AND METHODS: Five hundred and twenty-five school adolescents (242 males and 283 females) were randomly selected to participate in this study. Maximum height and average of power reached in countermovement jump and squat jump were provided by an Optojump device. Full and stepwise regression models were used to identify which anthropometric parameters significantly contributed to performance variables. RESULTS: All anthropometric parameters increased with age. Reference values and multiple prediction equations of vertical jump parameters were set based on a large sample of healthy Tunisian adolescents. The multiple regressions showed that age, mass, sitting height, waist size, fat-free mass and leg muscle volume for boys and mass for girls were the best predictors of jumping performances. CONCLUSION: This study provides normative data for jumping performances in Tunisian healthy adolescents aged 13-19 in both sexes. The percentiles values are calculated to estimate the levels of adolescents with high or low jumping performances.

Test-retest reliability, criterion-related validity, and minimal detectable change of the Illinois agility test in male team sport athletes.

The purposes of this study were first to assess the reliability and criterion-related validity of the Illinois change of direction (COD) Illinois Agility Test (IAGT) and second to determine whether a relationship with power and speed exists. A total of 105 male team sport athletes participated in this investigation. Repeat measurements in 89 subjects out of the 105 were performed to assess the test-retest reliability and the 95% confidence interval (CI) of the difference in the score between paired observations (minimal detectable change [MDC]95) of the COD IAGT. The intraclass correlation coefficient and the SEM values for the COD IAGT test were 0.96 (95% CI, 0.85-0.98) and 0.19 seconds, respectively. The smallest worthwhile change (0.20 seconds) for the IAGT was greater than its SEM (0.19 seconds). The MDC95 value for the IAGT was 0.52 seconds. Criterion-related validity of the COD IAGT was assessed in the 105 subjects. They performed the COD IAGT and the T-test. Both tests were significantly correlated (r = 0.31 [95% CI, 0.24-0.39]; p < 0.05). The correlation between COD IAGT, acceleration, straight speed, and leg power was analyzed in all the 105 subjects. Pearson moment correlation revealed no association between acceleration and the COD IAGT. However, significant correlations were observed between the COD IAGT and leg power (r = -0.39 [95% CI, -0.26 to -0.44]; p < 0.05), and speed (r = 0.42 [95% CI, 0.37-0.51]; p < 0.05). When controlling for speed with partial correlation, the significant relationship between the COD IAGT and leg power disappeared. In conclusion, the COD IAGT seems to be a reliable and valid test, whose performance is significantly related to speed rather than to acceleration and leg power.

Monitoring training load and fatigue in rugby sevens players.

PURPOSE: Trainers and physical fitness coaches' need a useful tool to assess training loads to avoid overtraining. However, perceived scales or questionnaires were required. Therefore, the purpose of this study was to assess whether a short 8-item questionnaire of fatigue could be a useful tool for monitoring changes in perceived training load and strain among elite rugby Sevens (7s) players during preparation for a major competition. METHODS: Sixteen elite rugby 7s players completed an 8-week training program composed of 6-week intense training (IT) and 2-week reduced training (RT). They were tested before (T0), after the IT (T1) and after the RT (T2). The quantification of the perceived training load and strain were performed by the session-RPE (rating of perceived exertion) method and concomitantly the 8-item questionnaire of fatigue was administered. RESULTS: Training load (TL) and strain (TS) and total score of fatigue (TSF from the 8-item questionnaire) increased during IT and decreased during RT. Simultaneously, physical performances decreased during IT and were improved after LT. The changes in TL, TS and TSF correlated significantly over the training period (r=0.63-0.83). CONCLUSIONS: These findings suggest that the short questionnaire of fatigue could be a practical and a sensitive tool for monitoring changes in training load and strain in team-sport athletes. Accordingly, the simultaneous use of the short questionnaire of fatigue along with the session-RPE method for perceived changes in training load and strain during training could provide additional information on the athletes' status, allowing coaches to prevent eventual states of overreaching or overtraining.

Training effects on peripheral muscle oxygenation and performance in children with congenital heart diseases.

We investigated the effect of training on peripheral muscular performance and oxygenation during exercise and recovery in children with congenital heart diseases (CHD). Eighteen patients with CHD aged 12 to 15 years were randomly assigned into either an individualized 12-week aerobic cycling training group (TG) or a control group (CG). Maximal voluntary contraction (MVC) and endurance at 50% MVC (time to exhaustion, T(lim)) of the knee extensors were measured before and after training. During the 50% MVC exercise and recovery, near-infrared spectroscopy (NIRS) was used to assess the fall in muscle oxygenation, i.e., deoxygenation ([Formula: see text]) of the vastus lateralis, the mean rate of decrease in muscle oxygenation, the half time of recovery (T(1/2R)), and the recovery speed to maximal oxygenation (R(S)). There was no effect of time on any parameter in the CG. After training, significant improvements were observed in TG for MVC (101.6 ± 14.0 vs. 120.2 ± 19.4 N·m, p < 0.01) and T(lim) (66.2 ± 22.6 vs. 86.0 ± 23.0 s, p< 0.01). Increased oxygenation (0.20 ± 0.13 vs. 0.15 ± 0.07 a.u., p < 0.01) and faster mean rate of decrease in muscle oxygenation were also shown after training in TG (1.22 ± 0.45 vs. 1.71 ± 0.78%·s(-1), p < 0.001). Moreover, a shorter recovery time was observed in TG after training for T(1/2R) (27.2 ± 6.1 vs. 20.8 ± 4.2 s, p < 0.01) and R(S) (63.1 ± 18.4 vs. 50.3 ± 11.4 s, p < 0.01). A significant relationship between the change in [Formula: see text] and both MVC (r = 0.95, p < 0.001) and T(lim) (r = 0.90, p < 0.001) in TG was observed. We concluded that exercise training improves peripheral muscular function by enhancing strength and endurance performance in children with CHD. This improvement was associated with increased oxygenation of peripheral muscles and faster recovery.

The Homeostasis Model Assessment-adiponectin (HOMA-AD) is the most sensitive predictor of insulin resistance in obese children.

OBJECTIVES: The aim of this study was to examine the efficacy of three indices i.e. adiponectin/leptin ratio, HOMA-IR and HOMA-AD in assessing insulin resistance among obese children. PATIENTS AND METHODS: One hundred and twenty-two obese children (57 girls, 65 boys): mean age 13.7±1.3 years, BMI 30.1±4.5kg/m(2), eight tanner stage I, 48 tanner stage II-III, 66 tanner stage IV-V, participated in this study. They were classified into four groups according to sex and the presence of metabolic syndrome characteristics: with metabolic syndrome (MS; 21 girls and 36 boys) and controls without metabolic syndrome (CON, 36 girls and 29 boys). The correlations between these three indices of insulin resistance and the MS criteria were analyzed using linear and multiple regressions and receiver operating characteristics (ROC) curves analysis. RESULTS: The majority of anthropometric and biological parameters as well as adiponectin/leptin ratio, HOMA-IR and HOMA-AD were significantly different between MS and CON in both sexes. Both HOMA-AD and HOMA-IR were significantly correlated with the majority of metabolic syndrome components than was the adiponectin/leptin ratio in MS of both sexes. In boys and girls with and without MS, multiple regression analyses highlighted that both HOMA-AD and adiponectin/leptin ratio (r=-0.99 and r=-0.54 for MS girls and boys respectively, 0.05

Six-minute walking test and the assessment of cardiorespiratory responses during weight-loss programmes in obese children.

PURPOSE: We assessed the exercise tolerance and cardiorespiratory responses during 2-month weight-loss programmes using the 6-minute walking test (6MWT) in obese children. METHODS: Twenty-eight male obese children were randomly assigned to either a control group (C), an energy restriction group (R), an exercise training at maximum lipid-oxidation (LIPOXmax) group (E), or an energy restriction/training group (RE). The body composition, the submaximal incremental cycling exercise, and the 6MWT were performed before and after the 2-month programme. RESULTS: . After the programme, RE group showed a significant improvement of body composition (body weight reduced by 6.3 ± 1.5 kg, p < 0.01), and an increase of 6-minute walking distance (6MWD) (+13.7%, p < 0.01). Similarly, maximum oxygen uptake calculated according to the American College of Science Medicine guideline (VO(2max) ACSM) and VO(2max) predicted from 6MWD were respectively higher (+12.9% and +10.0%, p < 0.01) than the R or E groups. Bland-Altman analysis highlighted an agreement of these two methods of VO(2max) measurement. Moreover, in all participants the 6MWD was significantly correlated with VO(2max) ACSM and LIPOXmax (r = 0.77, p < 0.001 and r = 0.67, p < 0.01; respectively) before the programme as well as their changes in percentage over the programme (r = 0.85 and r = 0.86, p < 0.0001; respectively). CONCLUSIONS: We concluded that a 2-month weight-loss programme including energy restriction and exercise training targeted at LIPOXmax improved body composition and cardiorespiratory tolerance in obese children. Furthermore, the 6MWT could be considered as a useful and reliable tool for the assessment and the follow-up of cardiorespiratory responses during weight-loss programme in obese children.