The key to success in elite athletes? Explicit and implicit motor learning in youth elite and non-elite soccer players

In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10–12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.     

Accelerometer data requirements for reliable estimation of habitual physical activity and sedentary time of children during the early years - a worked example following a stepped approach

This study presents a worked example of a stepped process to reliably estimate the habitual physical activity and sedentary time of a sample of young children. A total of 299 children (2.9 ± 0.6 years) were recruited. Outcome variables were daily minutes of total physical activity, sedentary time, moderate to vigorous physical activity and proportional values of each variable. In total, 282 (94%) provided 3 h of accelerometer data on ≥1 day and were included in a 6-step process: Step-1: determine minimum wear-time; Step-2: process 7-day-data; Step-3: determine the inclusion of a weekend day; Step-4: examine day-to-day variability; Step-5: calculate single day intraclass correlation (ICC) (2,1); Step-6: calculate number of days required to reach reliability. Following the process the results were, Step-1: 6 h was estimated as minimum wear-time of a standard day. Step-2: 98 (32%) children had ≥6 h wear on 7 days. Step-3: no differences were found between weekdays and weekend days (P ≥ 0.05). Step-4: no differences were found between day-to-day variability (P ≥ 0.05). Step-5: single day ICC’s (2,1) ranged from 0.48 (total physical activity and sedentary time) to 0.53 (proportion of moderate to vigorous physical activity). Step-6: to reach reliability (ICC = 0.7), 3 days were required for all outcomes. In conclusion following a 7 day wear protocol, ≥6 h on any 3 days was found to have acceptable reliability. The stepped-process offers researchers a method to derive sample-specific wear-time criterion.     

Effects of high-intensity interval training on cardiometabolic risk factors in overweight/obese women

The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids and body composition in overweight/obese women. Thirty women (mean ± SD; weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg · m²) were randomly assigned to ten 1-min high-intensity intervals (90%VO₂ peak, 1 min recovery) or five 2-min high-intensity intervals (80–100% VO₂ peak, 1 min recovery) or control. Peak oxygen uptake (VO₂ peak), peak power output (PPO), body composition and fasting blood lipids were evaluated before and after 3 weeks of training, completed 3 days per week. Results from ANCOVA analyses demonstrated no significant training group differences for any primary variables (P > 0.05). When training groups were collapsed, 1MIN and 2MIN resulted in a significant increase in PPO (?18.9 ± 8.5 watts; P = 0.014) and time to exhaustion (?55.1 ± 16.4 s; P = 0.001); non-significant increase in VO₂ peak (?2.36 ± 1.34 ml · kg^?1 · min^?1; P = 0.185); and a significant decrease in fat mass (FM) (??1.96 ± 0.99 kg; P = 0.011). Short-term interval exercise training may be effective for decreasing FM and improving exercise tolerance in overweight and obese women.     

Simulation of Fragment Impact on Multi-Layer Targets Using Contact Method

Cased explosives generate highly energetic fragments as their casing breaks up. Due to the complexity of casing fragment related behavior such as embedment, perforation and ricochet, it may be insufficient to use equivalent triangular pressure loading in fragment impact simulations. This simplified method may over- or under-predict the target response. Recently, a procedure using contact techniques has been proposed to overcome such difficulties. It has been shown that the new method has the inherent capability in modeling the multi-piece and multi-hit fragment impact problems in a more realistic way. To investigate the applicability of the proposed method to simulations involving multi-layer penetration, the selected problems of fragment impact on multi-layer targets are described in this paper. It is demonstrated that this method is capable of predicting the complicated multi-layer structural response caused by fragment impact and penetration. Modeling procedures and some technical issues are also discussed.     

Pepper Spray Cop and the American Dream: Using Synecdoche and Metaphor to Unlock Internet Memes’ Visual Political Rhetoric

Social media are increasingly important in protest movements for communication and organization. As such, scholars should consider these ephemeral messages as a tool for understanding such movements’ rhetoric. This article draws on Kjeldsen’s method for the critique of visual political rhetoric and adds consideration of intertextuality, synecdoche, and metaphor to demonstrate a method for the rhetorical analysis and a critique of Internet memes as visual, political rhetoric. The Pepper Spray Cop meme arising from Occupy Wall Street is presented as a case-study example. The article considers the centrality of the intertextual nature of memes as a unique form of visual rhetoric in activist contexts and contributes to the literature on user-generated and activist rhetoric.     

Validity of Self-Reported Pedometer Steps per Day in College Students

The purpose of this article was to examine the validity of self-reported pedometer steps/day. Forty-seven participants were provided a New Lifestyles NL-2000 (NL-2000; Lees Summit, MO, USA) pedometer and a physical activity (PA) diary for 3 weeks, but not informed of the data-storing capabilities. For weeks 2 and 3, each participant was given a step goal of 3,000 steps/day above week 1 average. A 2 × 3 repeated measures analysis of variance (ANOVA) was used to examine differences between reported steps/day. Bland–Altman plots assessed the mean bias and limits of agreement between reporting methods. Mean self-reported and NL-2000 steps/day were 9,264 ± 3,555 and 8,971 ± 3,590 steps/day (n = 26, p > .05). Mean biases were 216 ± 1,753 (week 1), –506 ± 1,355 (week 2), and –590 ± 1,360 (week 3) steps/day. Negative mean bias values indicate higher self-reported steps/day. Mean steps/day were similar between recording methods, but large differences were observed among individuals, suggesting self-reported steps/day may be valid for PA research at the population level, but not the individual level.     

Visual body pedagogies: how anti-oppressive education informs the teaching and learning of sporting bodies

In this article, the authors borrow from anti-oppressive education theory for its potential to disrupt how students visually conceive sporting bodies and to problematize the teaching and learning of these bodies within undergraduate physical education (PE) programs. Fourteen photo stories produced by students enrolled in PE programs at two universities were analysed using a semiotic approach to excavate the emergent themes of sporting bodies from the narratives. Relying on Kumashiro's anti-oppressive educational theoretical framework, the authors found that most of stories reified discursive practices that (re)produce gender oppression in sport. Despite these findings, the authors also discovered anti-oppressive pedagogies are useful for teaching against the body oppressions conveyed in the photo stories. How anti-oppressive education informs other areas of PE should be examined in the future.     

The kinematic differences between off-spin and leg-spin bowling in cricket

Spin bowling is generally coached using a standard technical framework, but this practice has not been based upon a comparative biomechanical analysis of leg-spin and off-spin bowling. This study analysed the three-dimensional (3D) kinematics of 23 off-spin and 20 leg-spin bowlers using a Cortex motion analysis system to identify how aspects of the respective techniques differed. A multivariate ANOVA found that certain data tended to validate some of the stated differences in the coaching literature. Off-spin bowlers had a significantly shorter stride length (p = 0.006) and spin rate (p = 0.001), but a greater release height than leg-spinners (p = 0.007). In addition, a number of other kinematic differences were identified that were not previously documented in coaching literature. These included a larger rear knee flexion (p = 0.007), faster approach speed (p < 0.001), and flexing elbow action during the arm acceleration compared with an extension action used by most of the off-spin bowlers. Off-spin and leg-spin bowlers also deviated from the standard coaching model for the shoulder alignment, front knee angle at release, and forearm mechanics. This study suggests that off-spin and leg-spin are distinct bowling techniques, supporting the development of two different coaching models in spin bowling.     

How much does lower body strength impact Paralympic running performance?

Objectives: Development of evidence-based methods of Paralympic classification requires research quantifying the relative strength of association between ratio-scaled measures of impairment and athletic performance. The purpose of this study was to quantify the extent to which muscle strength affects running performance in runners with and without brain impairment. Design: Cross-sectional study. Methods: Participants were 41 male runners: 13 with brain impairments (RBI) and 28 non-disabled (NDR). All participants completed a maximal 60-m sprint and a novel battery of three lower limb isometric strength tests. Results: RBI showed significantly lower strength scores compared with NDR on the more affected side in leg flexion (176 vs. 243?N), leg extension (993 vs. 1661?N) and plantarflexion (824 vs. 1457?N). Significant differences were also seen on the less affected side in plantarflexion (1072 vs. 1508?N). RBI were significantly slower in the acceleration phase (0–15?m) (3.2?s?±?0.3?vs. 2.8?s?±?0.2) and top speed phase (30?60?m) (4.3?s?±?0.6?vs. 3.8?s?±?0.3). Correlation analysis showed stronger relationships between strength and running performance in RBI than NDR; however, the correlations were not significant. Conclusions: This study evaluated measures to assess strength for the purposes of classification and found that the measures were significantly different in RBI compared with NDR indicating the tests were able to capture strength impairment in this population. This study indicates that strength may be an important impairment type to assess in this population, as impairments of muscle strength may influence the outcome of running performance in athletes with more severe impairments.     

Placing wireless tablets in clinical settings for patient education

Objective

The authors explored the feasibility and possible benefit of tablet-based educational materials for patients in clinic waiting areas.

Methods

We distributed eight tablets preloaded with diagnosis-relevant information in two clinic waiting areas. Patients were surveyed about satisfaction, usability, and effects on learning. Technical issues were resolved.

Results

Thirty-seven of forty patients completed the survey. On average, the patients were satisfied in all categories.

Conclusions

Placing tablet-based educational materials in clinic waiting areas is relatively easy to implement. Patients using tablets reported satisfaction across three domains: usability, education, and satisfaction.