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2.
We used systematic observation tools to explore the structure (i.e., activity and inactivity) and sequencing (i.e., the types of activities used) of football coaching sessions in Australia following the implementation of a new National Curriculum. Youth soccer coaches (n = 34), coaching within the Skill Acquisition (U11–U13 n = 19) and Game Training (U14–U17 n = 15) phases of the Football Federation Australia National Curriculum participated. Participants were filmed during a regular coaching session, with systematic observation of the session undertaken to provide a detailed analysis of the practice activities and coach behaviours. Findings indicated a session comprised of Playing Form activities (40.9%), Training Form activities (22.3%), inactivity (31%), and transitions between activities (5.8%). Coaches prescribed more Training Form activities (e.g., individual (5.4%) and drills (15.1%)) early in the session and progressed to Playing Form activities (i.e., small-sided games (15.3%) then larger games (24.8%)) later in the session. Most inactivity reflected the players listening to the coach – either in a team huddle (9.9%) or frozen on the spot during an activity (16.5%). In addition, coaches generally spent over 3 min communicating to players prior to explaining and introducing an activity regardless of when in the session the activity was scheduled.  相似文献   

3.
Carbohydrate (CHO) availability during endurance exercise seems to attenuate exercise-induced perturbations of cellular homeostasis and might consequently diminish the stimulus for training adaptation. Therefore, a negative effect of CHO intake on endurance training efficacy seems plausible. This study aimed to test the influence of carbohydrate intake on the efficacy of an endurance training program on previously untrained healthy adults. A randomized cross-over trial (8-week wash-out period) was conducted in 23 men and women with two 8-week training periods (with vs. without intake of 50g glucose before each training bout). Training intervention consisted of 4x45 min running/walking sessions/week at 70% of heart rate reserve. Exhaustive, ramp-shaped exercise tests with gas exchange measurements were conducted before and after each training period. Outcome measures were maximum oxygen uptake (VO2max) and ventilatory anaerobic threshold (VT). VO2max and VT increased after training regardless of CHO intake (VO2max: Non-CHO 2.6 ± 3.0 ml*min?1*kg?1 p = 0.004; CHO 1.4 ± 2.5 ml*min?1*kg?1 p = 0.049; VT: Non-CHO 4.2 ± 4.2 ml*min?1*kg?1 p < 0.001; CHO 3.0 ± 4.2 ml*min?1*kg?1 p = 0.003). The 95% confidence interval (CI) for the difference between conditions was between +0.1 and +2.1 ml*min?1*kg?1 for VO2max and between ?1.2 and +3.1 for VT. It is concluded that carbohydrate intake could potentially impair the efficacy of an endurance training program.  相似文献   

4.
The aim of this experiment was to determine the effectiveness of two video-based perceptual training approaches designed to improve the anticipatory skills of junior tennis players. Players were assigned equally to an explicit learning group, an implicit learning group, a placebo group or a control group. A progressive temporal occlusion paradigm was used to examine, before and after training, the ability of the players to predict the direction of an opponent's service in an in-vivo on-court setting. The players responded either through hitting a return stroke or making a verbal prediction of stroke direction. Results revealed that the implicit learning group, whose training required them to predict serve speed direction while viewing temporally occluded video footage of the return-of-serve scenario, significantly improved their prediction accuracy after the training intervention. However, this training effect dissipated after a 32 day unfilled retention interval. The explicit learning group, who received instructions about the specific aspects of the pre-contact service kinematics that are informative with respect to service direction, did not demonstrate any significant performance improvements after the intervention. This, together with the absence of any significant improvements for the placebo and control groups, demonstrated that the improvement observed for the implicit learning group was not a consequence of either expectancy or familiarity effects.  相似文献   

5.
Game-based training drills are popular in team sports. This study compared two game-based training conditions and official matches in team handball. Thirty-one women players wore inertial measurement units in five training sessions and five official matches. In training, 3vs3 and 6vs6 game-based training conditions were performed with a 5-min duration. PlayerLoad? and high-intensity events (HIEs; >2.5 m · s?1) were extracted from the raw data. Data were analysed using magnitude-based inferences and reported with effect sizes (ESs). PlayerLoad? · min?1 from all positions combined was 11.37 ± 0.49 (mean ± 90% confidence limits) and 9.71 ± 0.3 for the 3vs3 and 6vs6 conditions, respectively. Backs (ES: 1.63), wings (ES: 1.91), and pivots (ES: 1.58) had greater PlayerLoad? in 3vs3 than 6vs6. Substantially greater HIE · min?1 in 3vs3 occurred for all positions. There was substantially greater PlayerLoad? · min?1 in 3vs3 and 6vs6 than match play for backs, wings, and pivots. Wings (ES: 1.95), pivots (ES: 0.70), and goalkeeper (ES: 1.13) had substantially greater HIE · min?1 in 3vs3 than match play. This study shows greater PlayerLoad? and HIE in 3vs3 than 6vs6. Both game-based training conditions investigated in this study provide an overload in overall PlayerLoad?; however, additional exercises might be needed to overload HIE, especially for backs and pivots.  相似文献   

6.
The aim of this investigation is to assess the effectiveness of a 6-week balance training (BT) protocol, integrated in regular training sessions, on postural sway of young female volleyball players (n = 26, age 13.0 ± 0.2 years) divided into two groups (intervention and control; 13 per group). Trials were performed for bipedal and unipedal stance conditions before and after the BT protocol, using a pressure platform to collect center-of-pressure (COP) time series that were processed to calculate sway area, COP path length, and maximum displacement range in anteroposterior and mediolateral directions. The intervention group exhibited smaller sway areas in eyes closed conditions (intervention = 42.76 mm2, control = 67.60 mm2; p < 0.05) and Romberg quotients (intervention = 1.11 mm, control = 1.82 mm) in bipedal stance, while all the other parameters were unaffected. BT also reduced sway area (intervention = 122.70 mm2, control = 187.18 mm2) and anteroposterior COP displacements (intervention = 20.18 mm, control = 22.38 mm) of the non-dominant limb for single-leg stance. No significant change was found for the dominant limb. Although it is possible to hypothesize a beneficial effect of BT on young athletes, further investigations are required to clarify its actual effect on balance performance with respect to normal volleyball training.  相似文献   

7.
The aim of this investigation is to assess the effectiveness of a 6-week balance training (BT) protocol, integrated in regular training sessions, on postural sway of young female volleyball players (n = 26, age 13.0 +/- 0.2 years) divided into two groups (intervention and control; 13 per group). Trials were performed for bipedal and unipedal stance conditions before and after the BT protocol, using a pressure platform to collect center-of-pressure (COP) time series that were processed to calculate sway area, COP path length, and maximum displacement range in anteroposterior and mediolateral directions. The intervention group exhibited smaller sway areas in eyes closed conditions (intervention = 42.76 mm2, control = 67.60 mm2; p < 0.05) and Romberg quotients (intervention = 1.11 mm, control = 1.82 mm) in bipedal stance, while all the other parameters were unaffected. BT also reduced sway area (intervention = 122.70 mm2, control = 187.18 mm2) and anteroposterior COP displacements (intervention = 20.18 mm, control = 22.38 mm) of the non-dominant limb for single-leg stance. No significant change was found for the dominant limb. Although it is possible to hypothesize a beneficial effect of BT on young athletes, further investigations are required to clarify its actual effect on balance performance with respect to normal volleyball training.  相似文献   

8.
We assessed the effectiveness of two generalized visual training programmes in enhancing visual and motor performance for racquet sports. Forty young participants were assigned equally to groups undertaking visual training using Revien and Gabor's Sports Vision programme (Group 1), visual training using Revien's Eyerobics (Group 2), a placebo condition involving reading (Group 3) and a control condition involving physical practice only (Group 4). Measures of basic visual function and of sport-specific motor performance were obtained from all participants before and immediately after a 4-week training period. Significant pre- to post-training differences were evident on some of the measures; however, these were not group-dependent. Contrary to the claims made by proponents of generalized visual training, we found no evidence that the visual training programmes led to improvements in either vision or motor performance above and beyond those resulting simply from test familiarity.  相似文献   

9.
We examined the effectiveness of video-based decision training in national youth handball teams. Extending previous research, we tested in Study 1 whether a three-dimensional (3D) video training group would outperform a two-dimensional (2D) group. In Study 2, a 3D training group was compared to a control group and a group trained with a traditional tactic board. In both studies, training duration was 6 weeks. Performance was measured in a pre- to post-retention design. The tests consisted of a decision-making task measuring quality of decisions (first and best option) and decision time (time for first and best option). The results of Study 1 showed learning effects and revealed that the 3D video group made faster first-option choices than the 2D group, but differences in the quality of options were not pronounced. The results of Study 2 revealed learning effects for both training groups compared to the control group, and faster choices in the 3D group compared to both other groups. Together, the results show that 3D video training is the most useful tool for improving choices in handball, but only in reference to decision time and not decision quality. We discuss the usefulness of a 3D video tool for training of decision-making skills outside the laboratory or gym.  相似文献   

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13.
The influences of growth, training and various training methods were investigated by analysing long‐term training effects in young cross‐country and biathlon skiers (n = 129). Some athletes (n = 49) were studied six times in three years and some at least once a year during a four year period (n = 48). During three summer training periods skiers emphasized either intensive training or distance training or continued to train normally. The results indicated that maximal oxygen uptake (VO2 max) and heart volume increased between 15 and 20 years of age and the most significant changes in heart volume were observed between 16 and 18 years of age. International level skiers were able to increase their VO2 max and heart volume even after 20 years of age. Anaerobic threshold (AT, ml kg‐1 min‐1) increased like VO2 max but when expressed as a percentage of VO2 max, the AT was similar in every age group over 16 years of age. Intensive training at the intensity of anaerobic threshold or higher was observed to be most effective in producing improvements in VO2 max. Low‐intensity distance training was more effective in producing improvements in anaerobic threshold.  相似文献   

14.
ObjectiveTo examine the impact of a 6-week endurance training on red blood cell (RBC) aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.MethodsA total of 31 participants (17 females and 14 males) performed a 6-week moderate training protocol (three 1-h running sessions per week at 70% of maximal heart rate). Blood was sampled before and after the training. RBCs from each participant were fractioned according to density and age into 4 RBC subfractions. Subfractions were examined for changes of RBC properties, including aging distribution, RBC deformability, RBC microparticles, and phosphatidylserine concentrations. RBC and plasma nitrite levels were measured as indicators of nitric oxide metabolism.ResultsAerobic performance, peak oxygen consumption, ventilatory thresholds, velocity at the aerobic–anaerobic threshold, and lactate at exhaustion improved after training. The relative amount of both young RBCs and old RBCs increased, and the amount of the main RBC fraction decreased. Phosphatidylserine externalization and RBC-derived microparticles decreased. Overall deformability expressed as shear stress required to achieve half-maximum deformation to theoretical maximal elongation index at infinite shear stress improved in unfractioned RBCs (p < 0.001). Nitrite decreased in total (p = 0.001), young (p < 0.001), main (p < 0.001), and old (p = 0.020) aged RBCs and in plasma (p = 0.002), but not in very old RBCs.ConclusionThese results indicate that non-endurance-trained healthy participants benefit from a regular moderate running training program because performance-related parameters improve and a younger RBC population with improved RBC properties is induced, which might support oxygen supply in the microcirculation.  相似文献   

15.
A randomized controlled trial was conducted to examine eight weeks of resistance training (RT) with and without time-restricted feeding (TRF) in order to assess nutrient intake and changes in body composition and muscular strength in young recreationally active males. The TRF programme consisted of consuming all calories within a four-hour period of time for four days per week, but included no limitations on quantities or types of foods consumed. The RT programme was performed three days per week and consisted of alternating upper and lower body workouts. For each exercise, four sets leading to muscular failure between 8 and 12 repetitions were employed. Research visits were conducted at baseline, four, and eight weeks after study commencement. Measurements of total body composition by dual-energy X-ray absorptiometry and muscle cross-sectional area by ultrasound were obtained. Upper and lower body strength and endurance were assessed, and four-day dietary records were collected. TRF reduced energy intake by ～650?kcal per day of TRF, but did not affect total body composition within the duration of the study. Cross-sectional area of the biceps brachii and rectus femoris increased in both groups. Effect size data indicate a gain in lean soft tissue in the group that performed RT without TRF (+2.3?kg, d?=?0.25). Upper and lower body strength and lower body muscular endurance increased in both groups, but effect sizes demonstrate greater improvements in the TRF group. Overall, TRF reduced energy intake and did not adversely affect lean mass retention or muscular improvements with short-term RT in young males.  相似文献   

16.
Abstract

This study aimed to investigate the effect of whole body vibration (WBV) training on the knee kinematics and neuromuscular control after single-legged drop landings. Surface electromyographic (EMG) activity of the rectus femoris and hamstring muscles and knee and ankle accelerometry signals were acquired from 42 healthy volunteers. Participants performed three pre-test landings and after a recovery period of three minutes, they completed one set of six bouts of WBV each of one minute duration (30 Hz – 4 mm), followed by a single-leg drop landing. After the WBV intervention no significant changes were observed in the kinematic outcomes measured, although the time to stabilise the lower-limb was significantly lower after the vibration training (F(8,41) = 6.55; P < 0.01). EMG analysis showed no significant differences in the amplitude of rectus femoris or hamstring muscles after WBV training, however, significant differences in EMG frequency of the rectus femoris were found before (F(8,41) = 7.595; P < 0.01) and after toe-down (F(8,41) = 4.440; P < 0.001). Finally, no significant changes were observed in knee or ankle acceleration after WBV. Results suggest that WBV can help to acutely enhance knee neuromuscular control, which may have clinical significance and help in the design of rehabilitation programmes.  相似文献   

17.
Using a randomised cross-over design, free-living lunch intake and subjective appetite were examined in 10 children (9.8 ± 0.6 years) following high-intensity interval training (HIIT) versus a control sedentary (SED) period, within a school setting. The 22-min HIIT took place during a regular PE lesson and consisted of two rounds of 4 × 30 s sprints. Foods were offered at a regular school lunch immediately following HIIT and SED and were matched between conditions. All food was covertly weighed before and after the meal. Hunger, fullness and prospective consumption were reported immediately before and after HIIT/SED, using visual analogue scales. Heart rate was higher during HIIT than SED (159.3 ± 23.1 vs. 76.9 ± 2.2 bpm, P < 0.05). Lunch energy intake was not different (P = 0.52) following HIIT, compared to SED (2.06 ± 0.35 vs. 2.09 ± 0.29 MJ, respectively). There were no significant differences in macronutrient intake or subjective appetite (P > 0.05). Results suggest that HIIT can be implemented in a PE lesson immediately before lunch, without causing a compensatory increase in food consumption.  相似文献   

18.
Abstract

The objective of this study was to examine the chronic effects on strength and power of performing complex versus traditional set training over eight weeks. Fifteen trained males were assessed for throw height, peak velocity, and peak power in the bench press throw and one-repetition maximum (1-RM) in the bench press and bench pull exercises, before and after the eight-week programme. The traditional set group performed the pulling before the pushing exercise sets, whereas the complex set group alternated pulling and pushing sets. The complex set training sessions were completed in approximately half the time. Electromyographic (EMG) activity was monitored during both test sessions in an attempt to determine if it was affected as a result of the training programme. Although there were no differences in the dependent variables between the two conditions, bench pull and bench press 1-RM increased significantly under the complex set condition and peak power increased significantly under the traditional set condition. Effect size statistics suggested that the complex set was more time-efficient than the traditional set condition with respect to development of 1-RM bench pull and bench press, peak velocity and peak power. The EMG activity was not affected. Complex set training would appear to be an effective method of exercise with respect to efficiency and strength development.  相似文献   

19.
This meta-analysis investigated the maturation-related pattern of adaptations to resistance training in boy athletes. We included studies examining the effects of 4–16-week resistance training programmes in healthy boy athletes aged 10–18 years. Pooled estimates of effect size for change in strength across all studies (n = 19) were calculated using the inverse–variance random effects model for meta-analyses. Estimates were also calculated for groups based on likely biological maturity status (“before”, “during” and “after” peak height velocity). Using the standardised mean difference, resistance training increased strength across all groups (effect size = 0.98, [CI: 0.70–1.27]). Strength gains were larger during (1.11 [0.67–1.54]) and after (1.01 [0.56–1.46]) peak height velocity than before (0.5 [?0.06–1.07]). Adaptations to resistance training are greater in adolescent boys during or after peak height velocity. These findings should help coaches to optimise the timing of training programmes that are designed to improve strength in boy athletes.  相似文献   

20.
The aim of this study was to perform a biomechanical validation of a double poling imitation drill on a rollerboard. Six elite cross‐country skiers performed three imitation drill trials at maximal speed at 13° inclination and in double poling on roller skis on a paved road of 3°. Pole and strap forces, elbow and hip angles and EMG activity of eight upper body muscles were measured. Force curves showed similar characteristics, except for impact force occurring only at pole plant in double poling on roller skis. Double poling on a rollerboard includes an eccentric roll‐down phase not appearing in double polling on roller skis. Forces on the rollerboard were similar to those on roller skis. Courses of the elbow angles indicated similar shapes, except for the angle at the start of the propulsion phase and, consequently, during flexion (p < 0.01). Propulsion time and cycle duration were longer and frequency lower on the rollerboard (all p < 0.001). Muscle activities were not significantly different, except for stronger biceps brachii (p < 0.01) and weaker erector spinae activation (p < 0.05) on the rollerboard. Muscle coordination patterns showed similar onset and offset points of each muscle and comparable activations in both activities, except for biceps brachii. Two movement strategies on the rollerboard were found, which led to small differences in measured variables. The biomechanical validity of double poling on a rollerboard can be judged as moderately high, being aware of the differences in some variables that might be considered in training sessions on the rollerboard, particularly when using intervals with high number of repetitions.  相似文献   

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