Triathlon

The aim of this study was to determine the effect of prior cycling on EMG activity of selected lower leg muscles during running. Ten elite level triathletes underwent two testing sessions at race pace: a 40 km cycle followed by a 2 km run (CR) and a 10 km run followed by a 2 km run (RR). EMG data from selected lower limb muscles were collected at three sections of each run (0 km, 1 km and 2 km) for six strides using a portable data logger. Significant differences (p < 0.05) between condition were found for the level of activation (L_act) for biceps femoris (BF) during stance and vastus lateralis (VL) during flight and stance. Vastus medialis (VM) changed in L_act, during flight, between sections in the 2 km run. Furthermore, significant differences (p < 0.05) between condition were found for BF during stance and for rectus femoris (RF) and VM during flight. There was a significant difference (p < 0.05) in the duration of VL activation (D_act) across sections of the 2 km run. Findings from this investigation highlight changes in muscle function when changing from cycling to running and indicate a need to train specifically for the cycle to run transition. Such training may improve performance and reduce the risk of injury.     

Methodological considerations for the 3D measurement of the X-factor and lower trunk movement in golf

It is believed that increasing the X-factor (movement of the shoulders relative to the hips) during the golf swing can increase ball velocity at impact. Increasing the X-factor may also increase the risk of low back pain. The aim of this study was to provide recommendations for the three-dimensional (3D) measurement of the X-factor and lower trunk movement during the golf swing. This three-part validation study involved; (1) developing and validating models and related algorithms (2) comparing 3D data obtained during static positions representative of the golf swing to visual estimates and (3) comparing 3D data obtained during dynamic golf swings to images gained from high-speed video. Of particular interest were issues related to sequence dependency. After models and algorithms were validated, results from parts two and three of the study supported the conclusion that a lateral bending/flexion-extension/axial rotation (ZYX) order of rotation was deemed to be the most suitable Cardanic sequence to use in the assessment of the X-factor and lower trunk movement in the golf swing. The findings of this study have relevance for further research examining the X-factor its relationship to club head speed and lower trunk movement and low back pain in golf.     

Characteristics of the start in women's World Cup skeleton

This study characterizes key elements of the start in elite female World Cup skeleton athletes. The top 20 female competitors in three World Cup races were videotaped within a calibrated space to allow the following components of the start to be quantified: (1) acceleration (velocity at 15-m mark, time to 15-m mark), (2) capacity (time to load, total number of steps to load), and (3) load (velocity at 45-m mark). A correlation analysis was used to establish the relationship between the variables of interest and overall start time (15- to 65-m mark). Velocity at the 15-m mark accounted for 86% of the variance in overall start time at St. Moritz and 85% at Sigulda. A stepwise regression analysis revealed that approximately 89% of the variation in start time could be explained by velocity at the 15-m mark, time to load, and velocity at the 45-m mark. Of the variables analysed in this study, rapid acceleration to attain a high velocity at the 15-m mark was the most important component of a fast overall start time. The importance of the time to load and velocity at the 45-m mark vary according to the different track characteristics.     

The Turk's characteristic difficulties in learning English pronunciation

INTERNATIONAL ENCYCLOPEDIA OF COMMUNICATIONS. Erik Barnouw, editor in chief. 4 vols. New York: Oxford University Press, 1989. Published jointly with the Annenberg School of Communications, University of Pennsylvania; pp. 1 (Acti‐Deco): xxv+462; 2 (Demo‐Mead): 506; 3 (Mean‐Rumo): 490; 4 (Sapi‐Zwor): 455. $300.     

Feasibility of test administration and preliminary findings for cognitive control in the Burn 2 learn pilot randomised controlled trial

ABSTRACT

The feasibility requirements of administering field-based cognitive assessments are rarely reported. We examined the feasibility of administering a group-based cognitive test battery in a school setting with older adolescents. Several types of reliability were also assessed in the control group. Preliminary efficacy and the relationship between changes in fitness and changes in cognitive control were also explored following a 14-week HIIT intervention (3 sessions/week). Participants completed a cognitive test battery measuring inhibition (flanker), and working memory (n-back) at baseline and post-test. Health-related fitness assessments were also conducted. Test administration took approximately 30.8 ± 1.5 minutes to complete with up to six participants simultaneously. The test battery demonstrated acceptable reliability (ICC = 0.5–0.81), with significant changes observed for flanker incongruent accuracy, and 2-back non-target accuracy from baseline to post-test. Regarding efficacy, small-to-moderate effects were observed for accuracy outcomes, while several small associations were found between changes in fitness and changes in cognition. Findings from the current study suggest a cognitive test battery can be administered with older adolescents in a school setting. However, there remains a lack of adequate reporting of administration requirements for field-based cognitive assessments. Efficacy findings should be confirmed with a larger and more representative sample of older adolescents.     

Assessment of the effects of student response systems on student learning and attitudes over a broad range of biology courses

With the advent of wireless technology, new tools are available that are intended to enhance students' learning and attitudes. To assess the effectiveness of wireless student response systems in the biology curriculum at New Mexico State University, a combined study of student attitudes and performance was undertaken. A survey of students in six biology courses showed that strong majorities of students had favorable overall impressions of the use of student response systems and also thought that the technology improved their interest in the course, attendance, and understanding of course content. Students in lower-division courses had more strongly positive overall impressions than did students in upper-division courses. To assess the effects of the response systems on student learning, the number of in-class questions was varied within each course throughout the semester. Students' performance was compared on exam questions derived from lectures with low, medium, or high numbers of in-class questions. Increased use of the response systems in lecture had a positive influence on students' performance on exam questions across all six biology courses. Students not only have favorable opinions about the use of student response systems, increased use of these systems increases student learning.     

Cardiorespiratory and muscular fitness associations with older adolescent cognitive control

Background:Participation in physical activity supports greater cardiorespiratory fitness(CRF),a correlate of cognitive control.However,the relationship between muscular fitness(MF)and cognitive control is less clear.The present study investigated the differential relationship of CRF and MF with cognitive control in older adolescents.Methods:This cross-sectional study involved students(15
17 years old,n=541,43%female)from 20 secondary schools who completed tests of inhibition(modified flanker task),working memory(n-back task),CRF(Progressive Aerobic Cardiovascular Endurance Run),and MF(standing long jump and push-up test).Multilevel analyses tested the association between CRF or MF and cognitive outcomes while accounting for the influence of the other fitness variable and relevant demographic factors.Results:CRF predicted response accuracy during incongruent flanker trials,the condition requiring greater inhibition.For the working memory task,CRF predicted greater target accuracy and greater d’scores on the 1-back task,requiring lesser amounts of working memory.In the 2-back task,which requires greater amounts of working memory,CRF also predicted greater target and non-target accuracy and d’scores.Comparatively,MF did not predict any cognitive outcomes after adjustment for CRF.Conclusion:CRF was selectively related to better performance during task conditions that require greater amounts of inhibition and working memory.This finding suggests that CRF,but not MF,may benefit cognitive control in older adolescents.This selective influence of CRF on older adolescents’cognition highlights the value of aerobic physical activity.