The assessment of at-risk infants and toddlers with the Bayley Mental Scale and the Battelle Developmental Inventory: Beyond the data

The purpose of this study was to compare the usefulness of the Bayley Scales of Infant Development (BSID)-Mental Scales and the Battelle Developmental Inventory (BDI) in assessing the abilities of infants and toddlers from teen-parent families. The 34 children lived with their mothers, who ranged in age from 15 to 21. The results of the study indicate that these two developmental instruments cannot be used interchangeably and that one needs to look beyond the psychometric data in order to understand the results of infant and toddler assessment. The correlation between the BSID-Mental Development Index (MDI) and BDI Total score was −.03.     

False-performance feedback does not affect punching forces and pacing of elite boxers

Prior research indicates that providing participants with positive augmented feedback tends to enhance motor learning and performance, whereas the opposite occurs with negative feedback. However, the majority of studies were conducted with untrained participants performing unfamiliar motor tasks and so it remains unclear if elite athletes completing familiar tasks respond in a similar fashion. Thus, this study investigated the effects of three different versions of false-performance feedback on punching force (N), pacing (force over time) and ratings of perceived exertion (RPE) in 15 elite amateur male boxers. Athletes completed a simulated boxing bout consisting of three rounds with 84 maximal effort punches delivered to a punching integrator on four separate days. Day one was a familiarisation session in which no feedback was provided. In the following three days athletes randomly received false-positive, false-negative and false-neutral feedback on their punching performance between each round. No statistical or meaningful differences were observed in punching forces, pacing or RPE between conditions (P > 0.05; ≤ 2%). These null results could stem from the elite status of the athletes involved, the focus on performance rather than learning, or they may indicate that false feedback has a less potent effect on performance than previously thought.     

Influence of upright versus time trial cycling position on determination of critical power and W′ in trained cyclists

Body position is known to alter power production and affect cycling performance. The aim of this study was to compare mechanical power output in two riding positions, and to calculate the effects on critical power (CP) and W′ estimates. Seven trained cyclists completed three peak power output efforts and three fixed-duration trial (3-, 5- and 12-min) riding with their hands on the brake lever hoods (BLH), or in a time trial position (TTP). A repeated-measures analysis of variance showed that mean power output during the 5-min trial was significantly different between BLH and TTP positions, resulting in a significantly lower estimate of CP, but not W′, for the TTP trial. In addition, TTP decreased the performance during each trial and increased the percentage difference between BLH and TTP with greater trial duration. There were no differences in pedal cadence or heart rate during the 3-min trial; however, TTP results for the 12-min trial showed a significant fall in pedal cadence and a significant rise in heart rate. The findings suggest that cycling position affects power output and influences consequent CP values. Therefore, cyclists and coaches should consider the cycling position used when calculating CP.     

Race differences on the developmental test of Visual Motor Integration,the Slosson Intelligence Test,and the ABC Inventory

Preschoolers' scores on the Developmental Test of Visual Motor Integration (VMI), the Slosson Intelligence Test (SIT), and the ABC Inventory (ABCI) were analyzed for race and sex differences. Separate ANOVAs revealed no race effect on the VMI, whereas race differences favoring whites were found for the SIT and ABCI. There were no effects for sex on any measure, nor were there any interactions. Results are discussed in terms of the inconsistent findings for race effects in the perceptual-motor literature.     

如何培养运动员的最佳思维方式

许多教练员面临这样的困惑:有的运动员训练成绩突出,可比赛成绩平平;而有的运动员虽训练表现一般,但比赛成绩非常突出.这种情况的出现,在集体项目中,会增加教练员的选材困难:在个人项目中,会引起运动员对比赛的消极态度.     

The performance environment of the England youth soccer teams

In the present study, we examined the performance environment of the England youth soccer teams. Using a semi-structured protocol with a prospective sample, national coaches (n = 6), sport scientists (n = 3), and players (n = 4) were interviewed directly following international tournaments about the factors that positively and negatively influenced performance. Qualitative content analysis revealed the following factors as major positive influences on performance: adhering to a consistent tournament strategy, player understanding, strong team cohesion, organized entertainment activities, detailed knowledge of opposition, an effective physical rest/recovery strategy, and previous tournament experience. Major factors perceived to have negatively influenced performance included: over-coaching, player boredom, player anxiety, physical superiority of the opposition, physical fatigue over the tournament, problems sleeping, and lack of information on the opposition. Eight overall dimensions emerged to describe the performance environment: planning and organization, physical environment, tactical factors, development and performance philosophy, psychological factors, physical factors, social factors, and coaching. The findings support recent work that suggests the performance environment is multifaceted, with performance being contingent upon a broad range of interacting factors that go beyond the traditional psychosocial and physical domains.     

The effect of periodized resistance training on accelerative sprint performance

The purpose of this study was to assess the effect of periodized resistance training on accelerative sprint performance. Sixteen physically active men participated in a randomized controlled study. An experimental group (n = 10) completed an 8-week periodized resistance training intervention, while a control group (n = 6) did not train. Pre- and post-training measures of 20-m straight-line sprint time, including a 10-m split, maximum strength, and explosive strength, were recorded. Flight time, stance time, stride length, and stride frequency were quantified from digitized video recordings of the first three strides of the 20-m sprint. Resistance training resulted in significant increases in maximum strength (parallel back squat: 19%) and explosive strength (6-10%). However, both groups increased 0-10 m sprint times (experimental group = 6%; control group = 3%) while 10-20m times were reduced (experimental group = 7%; control group = 4%), highlighting the mechanical differences between the distinct sprint phases. The change during the 0-10m interval was accompanied by a reduction in stride frequency during the first three strides. Strength coaches should be aware that the potential benefits of increased muscular strength during short sprints are likely to be affected by mechanical specificity and that improvements in sprinting performance may not occur immediately after a period of resistance training.     

But I like PE: factors associated with enjoyment of physical education class in middle school girls

The current study examined associations between physical education (PE) class enjoyment and sociodemographic, personal, and perceived school environment factors among early adolescent girls. Participants included 1,511 sixth-grade girls who completed baseline assessments for the Trial of Activity in Adolescent Girls, with 50% indicating they enjoyed PE class a lot. Variables positively associated with PE class enjoyment included physical activity level, perceived benefits of physical activity, self-efficacy for leisure time physical activity, and perceived school climate for girls' physical activity as influenced by teachers, while body mass index was inversely associated with PE class enjoyment. After adjusting for all variables in the model, PE class enjoyment was significantly greater in Blacks than in Whites. In model testing, with mutual adjustment for all variables, self-efficacy was the strongest correlate of PE class enjoyment, followed by perceived benefits, race/ethnicity, and teachers' support for girls' physical activity, as compared to boys, at school. The overall model explained 11% of the variance in PE class enjoyment. Findings suggest that efforts to enhance girls' self-efficacy and perceived benefits and to provide a supportive PE class environment that promotes gender equality can potentially increase PE class enjoyment among young girls.     

On the temporal and behavioural consistency of pre-performance routines: an intra-individual analysis of elite basketball players' free throw shooting accuracy

The effectiveness of pre-performance routines on skilled performance in a self-paced skill has yet to be verified. In this study, we examine the importance of temporal and behavioural consistency in these routines. The duration and specific pattern of behaviours exhibited before each free throw (n = 284) were observed during 14 National Basketball Association play-off games. An intra-individual standardized score was calculated for each shot's duration. Each player's dominant behavioural routine was identified and each shot was classified as "sequence followed" or "sequence not followed". No difference was observed in the success rates of shots associated with brief, long, and regular duration routines (P > 0.05). However, players were more successful when they followed their dominant behavioural sequence (83.77% success) than when they deviated from their specific behavioural pattern (71.43% success) (P < 0.05). The findings are interpreted in light of relevant theory and implications for practice are discussed.