Influence of carbohydrate mouth rinsing on running and jumping performance during early morning soccer scrimmaging

Carbohydrate mouth rinse (CMR) is a novel method proposed to enhance endurance performance lasting ≤ 60 min. The current study examined the influence of CMR on anaerobic performance tasks in 11 collegiate female soccer players after an overnight fast. Athletes completed two experimental sessions, during which carbohydrate (CHO; 6% maltodextrin) or taste- and colour-matched placebo (PLA) mouth-rinse solutions were administered in a counterbalanced, double-blinded design. Three rounds of a 5-min scrimmage bout and series of performance tests including a single countermovement vertical jump (1VJ), a set of four consecutive vertical jumps, a 72-m shuttle run (SR72) and 18-m sprint comprised each trial. Thirst sensation (TS), session TS, ratings of perceived exertion (RPE) and session RPE were assessed as secondary outcomes. The first SR72 approached significance (p = 0.069), but no significant between-trials differences were observed for any of the mean performance tasks. The highest 1VJ scores did not differ for the first (CHO = 47.3 ± 3.4, PLA = 47.7 ± 3.5 cm; p = 0.43), second (CHO = 48.0 ± 4.1, PLA = 47.9 ± 3.5 cm; p = 0.82) or third bout (CHO = 47.4 ± 3.9, PLA = 48.1 ± 3.9 cm; p = 0.26). TS approached significance (p = 0.053) during the first bout. No significant differences (p > 0.05) were found for any of the perceptual variables. Current results fail to support ergogenic influence of CMR on anaerobic performance tasks in collegiate female athletes.     

Research assistantship experiences and subsequent research productivity

This paper is an examination of one component of research training programs, the research assistantship. Data are presented from a national study of the topic. Results of a survey with 3,963 respondents showed that genuine research assistantship experience is positively related to subsequent research involvement and productivity. More intensive data collection from the 50 most productive researchers and 50 nonproductive respondents resulted in identification of 35 variables that discriminate between the two groups (4 structural, 19 experiential, 4 supervisor-assistant interactions, and 8 perceptual). Clusters of variables resulting from factor analysis are presented and nondiscriminating variables are discussed. Recommendations are offered for designers and directors of programs in colleges and universities for use in training educational research personnel.     

The influence of impact location and angle on the dynamic impact response of a Hybrid III headform

To properly assess sports helmet performance, it is important to select impact conditions that yield high peak linear or angular accelerations. This was done by measuring the kinematic response of a Hybrid III headform when impacted with a modified Wayne State University linear impactor with special consideration for impact locations and angles. The 20 impact conditions (five locations and four angles) were then compared to published thresholds to identify the conditions, which were linked to an increased risk of head injury. These conditions were the following: 1A (linear 121.3g; angular 3.84 krad s⁻²), 2A (linear 102.1g; angular 9.28 krad s⁻²), 2C (linear 94.4g; angular 8.67 krad s⁻²), 3A (linear 132.8g; angular 9.38 krad s⁻²), 4A (linear 92.8g; angular 11.49 krad s⁻²), 4D (linear 113.3g; angular 12.86 krad s⁻²), 5A (linear 116.9g; angular 9.01 krad s⁻²) and 5D (linear 87.5g; angular 8.81 krad s⁻²). The results presented in this study were specific to the test rig used as well as the tested conditions; however, it is believed that a test protocol using the above impact conditions could identify the ability of sports helmets to reduce risk of head injuries.     

Prediction of 2000 m indoor rowing performance using a 30 s sprint and maximal oxygen uptake

The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 - 3.6 years, height 1.68 - 0.54 m, body mass 67.1 - 11.7 kg; mean - s ) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake ( V O 2 ) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest V O 2 measured during the test was recorded as V O 2max (mean = 3.18 - 0.35 l· min -1 ). Peak power (380 - 63.2 W) and mean power (368 - 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 - 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), V O 2max (l· min -1 ), V O 2max (ml·kg -1 ·min -1 ), V O 2 at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent V O 2max ) and V E max (l·min -1 ) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time 2000 =- 0.163 (Power)14.213 ·( V O 2max l· min -1 ) + 0.738· (Fatigue) + 567.259 ( R 2 = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while V O 2max and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively.     

Do clickers work for students with poorer grades and in harder courses?

We studied the impact of clickers, also known as electronic student response systems, on the performance of students on two undergraduate finance courses. Consistent with some of the recent literature, we found that clickers have very little impact on student performance, as measured by final course grades. Further, we found that clickers do not have a significant impact on course grades for students in relation to their designated performance ability (weak versus strong) or whether the course in question is less or more difficult. However, after simultaneously controlling for course difficulty and student aptitude, we found that clickers have a meaningfully positive impact on the performance of poorly performing students on more challenging quantitative courses. Our results suggest that the impact of clickers on student performance may depend on the type of student (academically weak, average or strong) and the type of course (average or difficult). This finding has particular implications for curriculum planners at the post-secondary level, although the findings may also have application at the secondary school level.     

Prediction of 2000 m indoor rowing performance using a 30 s sprint and maximal oxygen uptake

The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 +/- 3.6 years, height 1.68 +/- 0.54 m, body mass 67.1 +/- 11.7 kg; mean +/- s) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake (VO2) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest VO2 measured during the test was recorded as VO2max (mean = 3.18 +/- 0.35 l.min-1). Peak power (380 +/- 63.2 W) and mean power (368 +/- 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 +/- 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), VO2max (l.min-1), VO2max (ml.kg-1.min-1), VO2 at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent VO2max) and VEmax (l.min-1) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time2000 = -0.163 (Power) -14.213.(VO2max l.min-1) +0.738.(Fatigue) 7.259 (R2 = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while VO2max and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively.     

Designing discipline-specific roles for interdisciplinary learning: two comparative cases in an afterschool STEM + L programme

The current K-12 educational system often does not engage students in interdisciplinary learning. To address this need, we developed an integrated STEM?+?L (Science, Technology, Engineering, Math, and Digital Literacies) afterschool programme in which middle school students took discipline-specific roles (writer, scientist, artist, and engineer) and worked in small groups to produce multimodal science fictions. The study aims to investigate the effect of discipline-specific roles on students’ interdisciplinary and collaborative learning processes. Two groups were chosen as comparison cases because their final products indicated low and high levels in integrating science and literacy respectively. Analysing and visualising students’ individual role-changing patterns and examining their discourse in role-specific interactions revealed the following features for high-quality interdisciplinary learning: (1) Students need to be willing and able to enact not only expected roles, but also other roles; (2) Students need to develop awareness of their own and others’ role enactment; (3) Collaboration between students with different roles may follow a possible trajectory from solo-construction, to co-construction, to re-construction. This study also proposes instructional strategies related to the design of discipline-specific roles to facilitate interdisciplinary learning in STEM education.