Changes in muscle activity with increasing running speed

Electromyographic (EMG) activity of the leg muscles and the ground reaction forces were recorded in 17 elite male middle-distance runners, who performed isometric maximal voluntary contractions (MVC) as well as running at different speeds. Electromyograms were recorded from the gluteus maximus, vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior. The results indicated that the averaged EMG (aEMG) activities of all the muscles studied increased (P?<?0.05) with increasing running speed, especially in the pre-contact and braking phases. At higher speeds, the aEMG activities of the gastrocnemius, vastus lateralis, biceps femoris and gluteus maximus exceeded 100% MVC in these same phases. These results suggest that maximal voluntary contractions cannot be used as an indicator of the full activation potential of human skeletal muscle. Furthermore, the present results suggest that increased pre-contact EMG potentiates the functional role of stretch reflexes, which subsequently increases tendomuscular stiffness and enhances force production in the braking and/or propulsive phases in running. Furthermore, a more powerful force production in the optimal direction for increasing running speed effectively requires increased EMG activity of the two-joint muscles (biceps femoris, rectus femoris and gastrocnemius) during the entire running cycle.     

Comparison of maximal anaerobic running tests on a treadmill and track

Abstract

To develop a track version of the maximal anaerobic running test, 10 sprint runners and 12 distance runners performed the test on a treadmill and on a track. The treadmill test consisted of incremental 20-s runs with a 100-s recovery between the runs. On the track, 20-s runs were replaced by 150-m runs. To determine the blood lactate versus running velocity curve, fingertip blood samples were taken for analysis of blood lactate concentration at rest and after each run. For both the treadmill and track protocols, maximal running velocity (v _max), the velocities associated with blood lactate concentrations of 10 mmol · l^?1 ( v _10 mM) and 5 mmol · l^?1 ( v _5 mM), and the peak blood lactate concentration were determined. The results of both protocols were compared with the seasonal best 400-m runs for the sprint runners and seasonal best 1000-m time-trials for the distance runners. Maximal running velocity was significantly higher on the track (7.57 ± 0.79 m · s^?1) than on the treadmill (7.13 ± 0.75 m · s^?1), and sprint runners had significantly higher v _max, v _10 mM, and peak blood lactate concentration than distance runners (P<0.05). The Pearson product – moment correlation coefficients between the variables for the track and treadmill protocols were 0.96 (v _max), 0.82 (v _10 mM), 0.70 (v _5 mM), and 0.78 (peak blood lactate concentration) (P<0.05). In sprint runners, the velocity of the seasonal best 400-m run correlated positively with v _max in the treadmill (r = 0.90, P<0.001) and track protocols (r = 0.92, P<0.001). In distance runners, a positive correlation was observed between the velocity of the 1000-m time-trial and v _max in the treadmill (r = 0.70, P<0.01) and track protocols (r = 0.63, P<0.05). It is apparent that the results from the track protocol are related to, and in agreement with, the results of the treadmill protocol. In conclusion, the track version of the maximal anaerobic running test is a valid means of measuring different determinants of sprint running performance.     

Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners

Abstract

The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([Vdot]O_2max), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [Vdot]O_2max (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups < 0.08). All three modes of strength training used concurrently with endurance training were effective in improving treadmill running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as improving sprinting ability at the end of a race.     

Sailing in an Occupied Country: Protests by Estonian Emigrants Against the 1980 Tallinn Olympic Regatta

The sailing regatta for the Olympic games of 1980 was organized at the Pirita Sailing Centre in Tallinn. It is generally assumed that emigrant Estonians opposed the event. By December 1979, attempts to boycott the Moscow Olympics had faded. However, the Soviet invasion of Afghanistan again opened the question. Eventually a large number of Western countries stayed home and many others did not participate in the sailing regatta. The situation was discussed again in the Estonian emigrant press but the focus of the general discussion was on Afghanistan and the Baltic question remained in its shadow. Besides writing memorandums to state officials and the International Olympic Committee, Estonian emigrants organized public demonstrations and sports festivals to support their cause. Although general interest in the Baltic question increased due to the Olympic sailing contests, the interest diminished soon after the games.     

Cognitive correlates of math skills in third-grade students

Math achievement is not a unidimensional construct but includes different skills that require different cognitive abilities. The focus of this study was to examine associations between a number of cognitive abilities and three domains of math skills (knowing, applying and problem solving) simultaneously in a multivariate framework. Participants were 723 third-grade children (mean age?=?9.07) from 28 elementary schools. Confirmatory factor analyses with binary indicators showed that a four-factor model of math skills (Knowing-Recalling, Knowing-Computing, Applying and Problem Solving) and a nine-factor model of cognitive abilities (Nonverbal and Verbal Reasoning, Verbal Concepts, Planning, Visuo-Spatial Working Memory (WM), two types of Verbal WM, Phonological Awareness and Phonological WM) fit the data well. Results from structural equation modelling showed that verbal reasoning and verbal concepts were most consistently associated with math knowing and problem solving domains. Verbal concepts contributed also to the math applying domain. In addition, simultaneous processing of verbal WM predicted problem solving skills in math. The results can be used in supporting the learning process of students with difficulties in math.     

Longitudinal effects of verbal ability,memory capacity,and phonological awareness on reading performance

This study addresses the longitudinal relationship among verbal ability, memory capacity, phonological awareness, and reading performance. Data from 92 German children were used to explore the exact relation among these variables. Indicators of verbal ability, memory capacity, and phonological awareness were assessed in kindergarten and again after the first grade. The interrelationships among these factors, and the subsequent influence they have on decoding speed and reading comprehension during the second grade were examined via structural equation modeling procedures. Overall, the results of the longitudinal analyses show that the relationship of memory capacity and phonological awareness remains stable over time, and that memory capacity predicts performance on phonological awareness tasks in both kindergarten and second grade. Phonological awareness proved to be a significant predictor of decoding speed, which in turn considerably influenced reading comprehension.     

A Test of the Relationship Between Argumentativeness and Individualism/Collectivism in the United States and Finland

This study explored relationships between argumentativeness and collectivism/individualism in Finland and the United States. Data were gathered in the United States (n = 412) and Finland (n = 261). The analysis suggested: (a) collectivism was negatively correlated with argumentativeness, (b) individualism was positively correlated with argumentativeness, and (c) Finnish participants reported lower levels of argumentativeness than Americans. Cultural differences between the United States and Finland are discussed as reasons for the differences between the nations on argumentativeness.     

Contested childhoods across borders and boundaries: Insights from curriculum provisions in Northern Ireland and the Irish Free State in the 1920s

Conceptualisations and constructs of children and childhood are temporally and contextually grounded. Historical documents are rich sources of insight and understanding regarding how children were understood, valued and treated at various times by particular societies. This article explores the conceptualisation of children and childhood in the 26-county Irish Free State (South) and the 6-county Northern Ireland (North) in the 1920s following the partition of Ireland, through the lens of educational documentation, primarily national primary school curricula. The focus on both jurisdictions is interesting in the context of partition, exploring the sometimes divergent and often convergent ways in which children were conceptualised across borders and boundaries. This article reveals, using Sorin and Galloway’s framework as a conceptual and analytical tool, that conceptualisations of children were broadly similar in the North and South but differed in their focus and enactment in both fledgling states. These disparities are largely attributable to the very different political, social and religious orientations of both jurisdictions and the use of education as a vehicle for nation-building, as well as identity and gender formation. The article also explores alternative conceptualisations of children in education policy in the North and South by presenting case study ‘outliers’ of educational provision. A century since partition, conclusions and implications are noted that resonate with contemporary elements of convergence and divergence on educational policy and the conceptualisation of children across the island of Ireland.     

Classroom behavioural climate in inclusive education – a study on secondary students’ perceptions

Previous studies pointed out that dealing with difficult behaviour is perceived by teachers as a major challenge in inclusive settings. However, research on the students' perception of the classroom behavioural climate (CBC) is rare. Therefore, this study aims to examine students’ perceptions of CBC and to identify predictors of CBC as well as associated variables. The sample consists of 650 German students from secondary schools (5th-9th grade) of whom 83 students are diagnosed with special educational needs (SEN). CBC was measured via four subscales (‘students’ possibilities to study and concentrating on teaching’, ‘disruptive behaviour’, ‘physical and psychological safety’ and ‘caring for the physical environment’). Results show significant differences in students’ perceptions of CBC between students from different school tracks. Furthermore, gender (being male) and SEN (having a) predict the perception of ‘physical and psychological safety’. Additionally, social inclusion, emotional experience as well as teacher support and care are associated with CBC. Accordingly, a positive CBC is important for the successful implementation of inclusive education: while diversity in classrooms is a challenge for behavioural climate, poor behavioural climate may also pose specific barriers to learning for some students with SEN and thus is a general challenge for equity in inclusive classrooms.     

Constraints and Challenges on Learning and Construction of Identities at Work

This paper analyses and discusses different constraints on workplace learning, vocational development and formation of identity. We ask how the learning and development of vocational identities are related to the various learning constraints and restrictions present in the socio-cultural contexts of the workplace. The study utilizes 20 interviews of industrial designers and nursing staff in Finland. The data on the vocational students was collected with Internet questionnaires (N?=?1125) from these two fields; technology and transport, and social services and health care. The results indicated that constraints on learning and professional/vocational identity development at work were mainly social in nature among employees as well as students. Therefore, we suggest that the most necessary conditions for workers’ and students’ learning are related to the feeling of “weness” that arises from individuals’ active participation in the social community.