Specific physical trainability in elite young soccer players: efficiency over 6 weeks' in-season training.

The aim of the present study was to compare the effects of 3 training protocols (plyometric [PLYO], agility [AG], or repeated shuttle sprints [RS]) on physical performance in the same population of young soccer players. Forty-two youth-level male players (13.6±0.3-years; 1.65±0.07 m; 54.1±6.5 kg; body fat: 12.8±2.6%) participated in a short-term (6-week) randomized parallel fully controlled training study (pre-to-post measurements): PLYO group, n=10; AG group, n=10; RS group, n=12; and control group [CON] n=10. PLYO training = 9 lower limb exercises (2-3 sets of 8-12 repetitions). The AG group performed planned AG drills and direction changes. RS training consisted of 2-4 sets of 5-6x 20 to 30 m shuttle sprints (20 seconds recovery in between). Progressive overload principles were incorporated into the programme by increasing the number of foot contacts and varying the complexity of the exercises. Pre/post-training tests were: bilateral standing horizontal jump, and unilateral horizontal jumps, sprint (30 m with 10 m lap time), agility (20 m zigzag), and repeated sprint ability (RSA) (i.e. 6x30 m shuttle sprints: 2x15 m with 180° turns). Significant main effects for time (i.e. training application) and group (training type) were detected. Improvements in horizontal jumping were higher (p<0.01: ES=large) in PLYO. The RS group improved significantly more (p<0.01; ES=large) than other groups: 30 m sprint, RSAbest and RSAmean performances. Significantly greater increases in 20 m zigzag performance were observed following AG and RS training (4.0 and 3.8%, respectively) compared with PLYO (2.0%) and CON training (0.8%). No significant differences were reported in the RSAdec between groups. Elite young male soccer players' physical performances can be significantly and specifically improved either using PLYO or AG or RSA training over short-term in-season training.

The IGF-1/cortisol ratio as a useful marker for monitoring training in young boxers.

Training effects on plasma insulin-like growth factor-1 (IGF-1)/cortisol ratio were investigated in boxers. Thirty subjects were assigned to either the training or the control group (n = 15 in both). They were tested before the beginning of training (T0), after 5 weeks of intensive training (T1), and after 1 week of tapering (T2). Physical performances (Yo-Yo intermittent recovery test level-1), training loads, and blood sampling were obtained at T0, T1, and T2. Controls were only tested for biochemical and anthropometric parameters at T0 and T2. A significantly higher physical performance was observed at T2 compared to T1. At T1, cortisol levels were significantly increased whereas IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels remained unchanged compared to baseline. At T2, cortisol levels decreased while IGF-1 and IGFBP-3 levels increased. The IGF-1/cortisol ratio decreased significantly at T1 and increased at T2, and its variations were significantly correlated with changes in training loads and Yo-Yo intermittent recovery test level 1 (IRT1) performance over the training period. Cortisol variations correlated with changes in training load (r = 0.64; p < 0.01) and Yo-Yo IRT1 performance (r = 0.78; p < 0.001) at T1 whereas IGF-1 variations correlated only with changes in Yo-Yo IRT1 performance at T2 (r = 0.71; p < 0.001). It is concluded that IGF-1/cortisol ratio could be a useful tool for monitoring training loads in young trained boxers.

Agility training in young elite soccer players: promising results compared to change of direction drills.

The aim of this study was to compare the effect of two different training programmes - change of direction (COD) vs. agility (AG) - on straight sprint (SS), COD and AG test performances in young elite soccer players. Thirty-two soccer players (age: 14.5±0.9 years; height: 171.2±5.1 cm; body mass: 56.4±7.1 kg, body fat: 10.3±2.3%) participated in a short-term (6 weeks) training study. Players were randomly assigned to two experimental groups - training with change of direction drills (COD-G, n=11) or using agility training (AG-G, n= 11) - and to a control group (CON-G, n=10). All players completed the following tests before and after training: straight sprint (15m SS), 15 m agility run with (15m-AR-B) and without a ball (15m-AR), 5-0-5 agility test, reactive agility test (RAT), and RAT test with ball (RAT-B). A significant group effect was observed for all tests (p<0.001; η2=large). In 15m SS, COD-G and AG-G improved significantly (2.21; ES=0.57 and 2.18%; ES=0.89 respectively) more than CON-G (0.59%; ES=0.14). In the 15m-AR and 5-0-5 agility test, COD-G improved significantly more (5.41%; ES=1.15 and 3.41; ES=0.55 respectively) than AG-G (3.65%; ES=1.05 and 2.24; ES=0.35 respectively) and CON-G (1.62%; ES=0.96 and 0.97; ES=0.19 respectively). Improvements in RAT and RAT-B were larger (9.37%; ES=2.28 and 7.73%; ES=2.99 respectively) in RAT-G than the other groups. In conclusion, agility performance amongst young elite soccer could be improved using COD training. Nevertheless, including a conditioning programme for agility may allow a high level of athletic performance to be achieved.

Greater volumes of static and dynamic stretching within a warm-up do not impair star excursion balance performance.

Based on the conflicting static stretching (SS) literature and lack of dynamic stretching (DS) literature regarding the effects of differing volumes of stretching on balance, the present study investigated the effects of 4, 8, and 12 sets of SS and DS following a 5 min aerobic running warm-up on the star excursion balance test (SEBT). The objective was to examine an optimal stretch modality and volume to enhance dynamic balance. A randomized, within-subjects experimental design with repeated measures for stretching (SS and DS) versus no-stretching treatment was used to examine the acute effects of 10 (4 sets), 20 (8 sets), and 30 (12 sets) min, of 15s repetitions per muscle of SS and/or DS following a 5 min aerobic warm-up on the performance of the SEBT. Results indicated that a warm-up employing either SS or DS of any volume generally improves SEBT by a "small" amount with effect sizes ranging from 0.06 to 0.50 (11 of 18 conditions>75% likely to exceed the 1.3-1.9% smallest worthwhile change). Secondly, the difference between static and dynamic warm-up on this observed improvement with warm-up improvement was "trivial" to "moderate" (d=0.04 to 0.57) and generally "unclear" (only two of nine conditions>75% likely to exceed the smallest worthwhile change). Finally, the effect of increasing the volume of warm-up on the observed improvement with a warm-up is "trivial" to "small" (d<0.40) and generally "unclear" (only three of 12 conditions>75% likely to exceed the smallest worthwhile change). In summary, an aerobic running warm-up with stretching that increases core and muscle temperature whether it involves SS or DS may be expected to provide small improvements in the SEBT.

Effect of glissade-step on kinetic and kinematic variables of stag ring leaps with and without throw-catch of the ball in rhythmic gymnastics.

This study focuses on certain characteristics of the jump take-offs in rhythmic gymnastics (RG). Rhythmic gymnasts always perform their jumps with the same preferred run-up technique, proceeded by a chassé-step in most of the cases. The overall idea was to analyse other step-techniques that could be performged on one-leg, which could prepare jumps. The aim of this study was to compare kinetic and kinematic variables between three-stag ring leaps with and without throwing-ball, performed using the glissade-step as a preparatory phase for take-off with one-leg these were as follows: glissade stag ring leap without-ball (GSWB), throw-ball glissade stag ring leap (TBGS) and glissade throw-ball stag ring leap (GTBS). Seven members of the Tunisian RG national team took part in this study. The technical elements were recorded in 2D using two-cameras on a specially designed floor carpet where a force-plate was integrated. The results showed that the three-leaps had significant impacts on the performance variables, especially on the force, the velocity and the flexibility. The GTBS was the most effective leap as the throw took place during the jump, which has increased its technicality and the applied physical variables, the vertical force, the rate of force development, the horizontal and vertical velocities and displacements.

Effects of dominant somatotype on aerobic capacity trainability.

PURPOSE: This study examined the association between dominant somatotype and the effect on aerobic capacity variables of individualised aerobic interval training. METHODS: Forty one white North African subjects (age 21.4+/-1.3 years; Vo2max = 52.8+/-5.7 ml kg(-1) min(-1)) performed three exercise tests 1 week apart (i) an incremental test on a cycle ergometer to determine Vo2max and Vo2 at the second ventilatory threshold (VT2); (ii) a VAM-EVAL track test to determine maximal aerobic speed (vVo2max); and (iii) an exhaustive constant velocity test to determine time limit performed at 100% vVo2max (tlim100). Subjects were divided into four somatometric groups: endomorphs-mesomorphs (Endo-meso; n = 9), mesomorphs (Meso; n = 11), mesomorphs-ectomorphs (Meso-ecto; n = 12), and ectomorphs (Ecto; n = 9). Subjects followed a 12 week training program (two sessions/week). Each endurance training session consisted of the maximal number of successive fractions for each subject. Each fraction consisted of one period of exercise at 100% of vVo2max and one of active recovery at 60% of vVo2max. The duration of each period was equal to half the individual tlim100 duration (153.6+/-39.7 s). After the training program, all subjects were re-evaluated for comparison with pre-test results. RESULTS: Pre- and post-training data were grouped by dominant somatotype. Two way ANOVA revealed significant somatotype-aerobic training interaction effects (p<0.001) for improvements in vVo2max, Vo2max expressed classically and according to allometric scaling, and Vo2 at VT2. There were significant differences among groups post-training: the Meso-ecto and the Meso groups showed the greatest improvements in aerobic capacity. CONCLUSION: The significant somatotype-aerobic training interaction suggests different trainability with intermittent and individualised aerobic training according to somatotype.

Effects of intra-session concurrent endurance and strength training sequence on aerobic performance and capacity.

AIM: To examine the effects of the sequencing order of individualised intermittent endurance training combined with muscular strengthening on aerobic performance and capacity. METHODS: Forty eight male sport students (mean (SD) age 21.4 (1.3) years) were divided into five homogeneous groups according to their maximal aerobic speeds (vV*o2max). Four groups participated in various training programmes for 12 weeks (two sessions a week) as follows: E (n = 10), running endurance training; S (n = 9), strength circuit training; E+S (n = 10) and S+E (n = 10) combined the two programmes in a different order during the same training session. Group C (n = 9) served as a control. All the subjects were evaluated before (T0) and after (T1) the training period using four tests: (1) a 4 km time trial running test; (2) an incremental track test to estimate vV*o2max; (3) a time to exhaustion test (t(lim)) at 100% vV*o2max; (4) a maximal cycling laboratory test to assess V*o2max. RESULTS: Training produced significant improvements in performance and aerobic capacity in the 4 km time trial with interaction effect (p < 0.001). The improvements were significantly higher for the E+S group than for the E, S+E, and S groups: 8.6%, 5.7%, 4.7%, and 2.5% for the 4 km test (p < 0.05); 10.4%, 8.3%, 8.2%, and 1.6% for vV*o2max (p < 0.01); 13.7%, 10.1%, 11.0%, and 6.4% for V*o2max (ml/kg(0.75)/min) (p < 0.05) respectively. Similar significant results were observed for t(lim) and the second ventilatory threshold (%V*o2max). CONCLUSIONS: Circuit training immediately after individualised endurance training in the same session (E+S) produced greater improvement in the 4 km time trial and aerobic capacity than the opposite order or each of the training programmes performed separately.

Asthma in Tunisian elite athletes.

Several studies in the past few decades have shown that very intense and repeated exercise, particularly when performed over many years, could cause respiratory health problems. The prevalence of exercise-induced asthma has increased in the athletic population, particularly in elite athletes and has not been published in North African athletes. The aim of this study was to determine the prevalence of exercise-induced asthma and/or exercise-induced bronchoconstriction in Tunisian elite athletes. Each participant responded to a questionnaire about respiratory symptoms and medical history and underwent a resting spirometry testing before exercise. Exercise-induced bronchoconstriction was defined as a decrease of at least 15% in pre-exercise forced expiratory volume in one second at any time point after exercise. Post-exercise spirometry revealed the presence of exercise induced bronchoconstriction in 14 out of 107 (13%) elite athletes, while only 1.8% of the subjects reported having previously diagnosed asthma. The prevalence of exercise-induced bronchoconstriction was 19% (8/42) among those athletes training outdoors and 10% (6/65) among those training indoors. In conclusion, our findings indicate that a significant number of Tunisian athletes had exercise-induced bronchoconstriction while not diagnosed before.