The Impact of Sport-discipline and Sex on Physical Fitness and Bone Markers in Athletes.

This study was performed to determine the impact of sex and sport-discipline on physical fitness and bone markers in young sub-elite track and field athletes. One hundred and forty-four track and field sub-elite athletes (78 males aged 17.8±1.6 years; 66 females aged 17.2±1.9 years) volunteered to participate in this study and were categorized according to their disciplines in endurance (EG: n=67) or power athletes (PG: n=77). A significant main effect of sex was observed for C-telopeptide type I collagen (CTx) (F=11.37; p<0.001; η2=0.10, moderate), for osteocalcin (OC) (F=8.58; p<0.004; η2=0.09, moderate) and for N-terminal propeptide of procollagen type I (PINP) (F=7.96; p<0.05; η2=0.07, moderate). The average CTx, OC and P1NP levels were significantly higher in males compared with females (0.05

The Influence of Maturity Status on Dynamic Balance Following 6 Weeks of Eccentric Hamstring Training in Youth Male Handball Players.

Information about when to apply an appropriate eccentric hamstring strength training stimulus during long-term athlete development is essential for effective programming and improving balance performance. This study examined the effects of six-week eccentric hamstring training on dynamic balance performance in youth handball players of different maturity statuses (pre- or post-peak height velocity (PHV)). A randomized controlled design with 45 young male handball players (14.6 ± 0.3 years) from a local national handball club were randomly allocated to a 6 week, twice weekly eccentric hamstring training in two experimental groups: a pre-PHV (maturation offset: −2.13 ± 0.63, n = 10) and post-PHV (maturation offset: 0.79 ± 0.34, n = 12) group and two control groups: maturation offset: −2.09 ± 0.61, n = 10 and maturation offset: 0.55 ± 0.67, n = 13. Dynamic balance performance was evaluated by using the composite score during the lower quarter Y-balance test from pre- and post-intervention. A significant effect on balance scores was found from pre to post (F = 11.4; p = 0.002; η2p = 0.22), intervention (F = 5.4; p = 0.025; η2p = 0.12), and maturation (F = 369; p < 0.001; η2p = 0.9), but no significant interaction effects were found (F ≥ 3.3; p ≥ 0.077; η2p ≤ 0.07). Post hoc analysis revealed that the post-PHV group had a higher score than the pre-PHV group. Furthermore, that dynamic balance increased in the post-PHV group after intervention much more in the control post-PHV group. It was concluded that somatic maturation influences dynamic balance performance and that eccentric hamstring training results in greater improvement in balance performance in young male handball players for the post-pubertal group.

The Effects of 6 Weeks Eccentric Training on Speed, Dynamic Balance, Muscle Strength, Power, and Lower Limb Asymmetry in Prepubescent Weightlifters.

ABSTRACT: Hammami, R, Duncan, MJ, Nebigh, A, Werfelli, H, and Rebai, H. The effects of 6 weeks eccentric training on speed, dynamic balance, muscle strength, power and lower limb asymmetry in prepubescent weightlifters. J Strength Cond Res 36(4): 955-962, 2022-This study examined whether 6 weeks of twice-weekly in-season hamstring eccentric training would enhance selected performance-related abilities in prepubescent male weightlifters. Twenty elite weightlifters (11.1 ± 0.8 years) were randomly split into an eccentric training intervention group (INT n = 10) or a control group (CON) that maintained their standard in-season regimen (n = 10). Pre-intervention and postintervention speed, dynamic balance, muscle strength, power, and lower limb (LL) asymmetry were assessed. Analysis of covariance controlling for maturation was used to determine any differences in the performance variables. There were no significant changes in muscle strength, dynamic balance, or LL asymmetry (all p < 0.05) because of the intervention. Both 10-m (p = 0.001) and 30-m (p = 0.007) sprint speed and agility (p = 0.049) improved to a greater extent in INT compared with the CON group. Similar results were evident for the standing long jump (p = 0.015) and 3 hop test (p = 0.004) where performance improved to a greater magnitude in INT compared with CON groups. This study suggests that eccentric training, undertaken twice weekly for 6-weeks results in positive changes in sprint speed, change of direction speed, and power performance, but not muscle strength, dynamic balance, or LL asymmetry in prepubertal weightlifters.

Speed Improves With Eccentric Hamstring Training in Athletes of Different Maturity Status.

PURPOSE: To investigate the effects of an eccentric hamstring strength training program (EHT) on sprint performance (10-, 20-, and 30-m sprint times) and change of direction speed (4 × 5-m shuttle run and T-Half test) in male European handball athletes at 2 maturity statuses (prepeak and postpeak height velocity [PHV]). METHODS: Forty-five participants (12.68 [1.58] y) were divided into pre-PHV and post-PHV and randomly allocated to a control or intervention group, which performed a guided 2 day per week 6-week EHT of 5 exercises. A mixed-model (within- and between-factor) analysis of variance was conducted. RESULTS: A significant effect (P < .05) of the interaction time × maturity × training was observed in the T-Half, 10, and 30 m tests. Both intervention groups significantly improved in all the tests, except in the 20 m sprint and the post-PHV in the 10 m sprint. Improvements ranged between 0.93% and 5.74% (effect size: 0.07-0.79). Both control groups yielded no improvements in almost all the tests. The improvements of both groups undergoing the intervention (pre-PHV and post-PHV) were not significantly different (only a tendency in the 10 m sprint). CONCLUSION: An EHT program combined with European-handball training improve change of direction and sprint performance in pre-PHV and post-PHV male players. Professionals training European handball and similar team-sport athletes should consider including EHT regardless of athlete's maturity.

Association Between Mental Imagery and Change of Direction Performance in Young Elite Soccer Players of Different Maturity Status.

Previous studies have not considered the potential influence of maturity status on the relationship between mental imagery and change of direction (CoD) speed in youth soccer. Accordingly, this cross-sectional study examined the association between mental imagery and CoD performance in young elite soccer players of different maturity status. Forty young male soccer players, aged 10-17 years, were assigned into two groups according to their predicted age at peak height velocity (PHV) (Pre-PHV; n = 20 and Post-PHV; n = 20). Participants were evaluated on soccer-specific tests of CoD with (CoDBall-15m) and without (CoD-15m) the ball. Participants completed the movement imagery questionnaire (MIQ) with the three- dimensional structure, internal visual imagery (IVI), external visual imagery (EVI), as well as kinesthetic imagery (KI). The Post-PHV players achieved significantly better results than Pre-PHV in EVI (ES = 1.58, large; p < 0.001), CoD-15m (ES = 2.09, very large; p < 0.001) and CoDBall-15m (ES = 1.60, large; p < 0.001). Correlations were significantly different between maturity groups, where, for the pre-PHV group, a negative very large correlation was observed between CoDBall-15m and KI (r = -0.73, p = 0.001). For the post-PHV group, large negative correlations were observed between CoD-15m and IVI (r = -0.55, p = 0.011), EVI (r = -062, p = 0.003), and KI (r = -0.52, p = 0.020). A large negative correlation of CoDBall-15m with EVI (r = -0.55, p = 0.012) and very large correlation with KI (r = -0.79, p = 0.001) were also observed. This study provides evidence of the theoretical and practical use for the CoD tasks stimulus with imagery. We recommend that sport psychology specialists, coaches, and athletes integrated imagery for CoD tasks in pre-pubertal soccer players to further improve CoD related performance.

Improvement of Physical Performance Following a 6 Week Change-of-Direction Training Program in Elite Youth Soccer Players of Different Maturity Levels.

Background: Change-of-direction (CoD) is a necessary physical ability of a field sport and may vary in youth players according to their maturation status. Objectives: The aim of this study is: to compare the effectiveness of a 6-week CoD training intervention on dynamic balance (CS-YBT), horizontal jump (5JT), speed (10 and 30-m linear sprint times), CoD with (15 m-CoD + B) and without (15 m-CoD) the ball, in youth male soccer players at different levels of maturity [pre- and post-peak height velocity (PHV)]. Materials and Methods: Thirty elite male youth soccer players aged 10-17 years from the Tunisian first division participated in this study. The players were divided into pre- (G1, n = 15) and post-PHV (G2, n = 15) groups. Both groups completed a similar 6-week training program with two sessions per week of four CoD exercises. All players completed the following tests before and after intervention: CS-YBT; 5 JT; 10, 30, and 15 m-CoD; and 15 m-CoD + B, and data were analyzed using ANCOVA. Results: All 30 players completed the study according to the study design and methodology. Adherence rate was 100% across all groups, and no training or test-related injuries were reported. Pre-PHV and post-PHV groups showed significant amelioration post-intervention for all dependent variables (after test > before test; p < 0.01, d = 0.09-1.51). ANOVA revealed a significant group × time interaction only for CS-YBT (F = 4.45; p < 0.04; η2 = 0.14), 5JT (F = 6.39; p < 0.02; η2 = 0.18), and 15 m-CoD (F = 7.88; p < 0.01; η2 = 0.22). CS-YBT, 5JT, and 15 m-CoD improved significantly in the post-PHV group (+ 4.56%, effect size = 1.51; + 4.51%, effect size = 1.05; and -3.08%, effect size = 0.51, respectively), more than the pre-PHV group (+ 2.77%, effect size = 0.85; + 2.91%, effect size = 0.54; and -1.56%, effect size = 0.20, respectively). Conclusion: The CoD training program improved balance, horizontal jump, and CoD without the ball in male preadolescent and adolescent soccer players, and this improvement was greater in the post-PHV players. The maturity status of the athletes should be considered when programming CoD training for soccer players.

Somatotype Hormone Levels and Physical Fitness in Elite Young Soccer Players over a Two-Year Monitoring Period.

The effect of two soccer-training seasons on the growth, development and somatotype hormone concentrations of elite youth soccer players were evaluated. Eighteen elite soccer players and 18 age-matched non-athletic control subjects participated in the study. Anthropometric-measurements, aerobic and anaerobic performance tests and serum concentrations of insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), and growth hormone (GH) were assessed at 5 time points across two competitive seasons. Soccer players revealed higher GH, IGF-1 and IGFBP-3 than the control group across all-time points. Significant moderate correlations were observed only in soccer players between hormonal concentrations (IGF-1 and IGFBP-3) and the jumping tests (r = 0.45-0.48; p < 0.01). Somatotropic axis hormones, anthropometric and physical parameters increased to a greater degree with growth and soccer training combined compared to growth alone. Results from this investigation revealed that intense training did not impair growth or development in these young soccer players across 2-year period.

Bone Turnover Markers and Lean Mass in Pubescent Boys: Comparison Between Elite Soccer Players and Controls.

The aim of this study was to examine the relationship between bone mass and bone turnover markers with lean mass (LM) in pubescent soccer players. Two groups participated in this study, which included 65 elite young soccer players who trained for 6-8 hours per week and 60 controls. Bone mineral density; bone mineral content in the whole body, lower limbs, lumbar spine, and femoral neck; biochemical markers of osteocalcin; bone-specific alkaline phosphatase; C-telopeptide type I collagen; and total LM were assessed. Young soccer players showed higher bone mineral density and bone mineral content in the whole body and weight-bearing sites (P < .001). Indeed, the total LM correlated with whole-body bone mineral density and bone mineral content (P < .001). There were significant differences within the bone formation markers and osteocalcin (formation)/C-telopeptide type I collagen (resorption) ratio between young soccer players compared with the control group, but no significant difference in C-telopeptide type I collagen was observed between the 2 groups. This study showed a significant positive correlation among bone-specific alkaline phosphatase, osteocalcin, and total LM (r = .29; r = .31; P < .05) only for the young soccer players. Findings of this study highlight the importance of soccer practice for bone mineral parameters and bone turnover markers during the puberty stage.

Enhanced bone mass and physical fitness in prepubescent basketball players.

The aim of this study was to examine the effect of basketball practice on bone acquisition in the prepubertal age. In total, 48 prepubescent male basketball players aged 11.1 ± 0.8 yr, Tanner stage 1, were compared with 50 controls matched for age and pubertal stage. Areal bone mineral density, bone mineral content (BMC), and bone area (BA) in deferent sites associated with anthropometric parameters were measured by dual-energy X-ray absorptiometry. Running and jumping tests were performed. Analysis of Student's impaired t-test revealed that basketball players attained better results in all physical fitness tests (p < 0.05). They also exhibited significantly greater BMC and BA in whole body, upper and lower extremities, trochanter, total hip, and whole right and left radius (p < 0.001) compared with the controls. No significant differences were observed between groups in right and left ultradistal and third distal radius and spinal regions, BMC, and BA, whereas a significant positive correlation was reported between lean mass, BMC, and BA of lower limbs. In summary, basketball practice in prepubertal age is associated with improved physical fitness and enhanced lean and bone mass in loaded sites.

Effects of a soccer season on anthropometric characteristics and physical fitness in elite young soccer players.

The aim of this study was to evaluate the effect of a soccer-training season on the anthropometric and performance characteristics of elite youth soccer players. Two groups (age: 14.4 years) participated in this study: (1) 24 soccer players training 8 to 10 hours per week and (2) 26 non-athletic boys used as controls. Anthropometric measurements, aerobic (Yo-Yo Intermittent Recovery test level 1) and anaerobic (counter-movement-jump (CMJ), squat-jump (SqJ), five-jump-test (5JT), and speed (T5m, 10 m, 30 m)) performances were assessed twice during 8 months (T0: October; T1: May) of the competitive season. Data showed significant differences in height and weight at T0 between the two groups (P < 0.05), while no difference in the percentage of body fat (%BF) was observed. However, the soccer players were significantly taller and had lower %BF than age-matched controls at T1. Compared to the controls, the soccer players attained better results in the physical fitness test (P < 0.05) at T0 and T1 except in (T5m) sprinting speed. Hence, significant improvements (P < 0.05) in physical parameters were observed between T0 and T1 only in soccer players. The results demonstrate that soccer-training season was able to provide maturation free improvement in anthropometric and performance characteristics in young soccer players during the training season.

Bone mineral density of young boy soccer players at different pubertal stages: relationships with hormonal concentration.

OBJECTIVES: To examine the effects of soccer in relation with the hormonal concentration, on the bone mass of young Tunisian players at different pubertal stages. METHODS: Two groups of 152 young boys (age: 13.3+/-0.9 years) participated in this study: (1) 91 soccer players, and (2) 61 non-athletic boys used as control subjects. The bone mineral density (BMD) and the bone mineral content (BMC) were measured by dual-energy X-ray absorptiometry (DXA). Pubertal stages were assessed, and serum concentrations of insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), growth hormone (GH) and the total testosterone were measured. RESULTS: The BMD and BMC for whole body, lumbar spine, femoral neck, pelvis and lower limbs were higher in soccer players than in controls (p<0.001). In early puberty, the soccer players also exhibited significantly greater BMD and BMC in the whole body and in weight-bearing bones compared with the controls (p<0.001). However, there was no intersubject variability due to puberty in either BMD or BMC. The pubescent soccer players had significantly higher hormonal concentrations of IGF-1 and IGFBP-3 than their counterpart controls (p<0.05). Moreover, the whole body BMD was significantly (p<0.001) correlated with GH, IGF-1 and IGFBP-3 but not with the testosterone concentrations. CONCLUSION: The soccer participation of boys is generally associated with the improvement of their bone mass which is mainly marked at early and late puberty. The relationships between somatotropic axis hormones and BMD of the players may be linked to the parallel development of these two parameters during puberty.