Test–retest reliability of a battery of field-based health-related fitness measures for adolescents

Abstract

The main aim of this study was to determine the test–retest reliability of existing tests of health-related fitness. Participants (mean age 14.8 years, s = 0.4) were 42 boys and 26 girls who completed the study assessments on two occasions separated by one week. The following tests were conducted: bioelectrical impedance analysis (BIA) to calculate percent body fat, leg dynamometer, 90° push-up, 7-stage sit-up, and wall squat tests. Intra-class correlation (ICC), paired samples t-tests, and typical error expressed as a coefficient of variation were calculated. The mean percent body fat intra-class correlation coefficient was similar for boys (ICC = 0.95) and girls (ICC = 0.93), but the mean coefficient of variation was considerably higher for boys than girls (22.2% vs. 12.2%). The boys' coefficients of variation for the tests of muscular fitness ranged from 9.0% for the leg dynamometer test to 26.5% for the timed wall squat test. The girls' coefficients of variation ranged from 17.1% for the sit-up test to 21.4% for the push-up test. Although the BIA machine produced reliable estimates of percent body fat, the tests of muscular fitness resulted in high systematic error, suggesting that these measures may require an extensive familiarization phase before the results can be considered reliable.     

Velocity and acceleration before contact in the tackle during rugby union matches

Abstract

The velocity and acceleration at which the ball-carrier or tackler enters the tackle may contribute to winning the contest and prevailing injury free. Velocity and acceleration have been quantified in controlled settings, whereas in match-play it has been subjectively described. The purpose of this study was to determine the velocity and acceleration of the ball-carrier and tackler before contact during match-play in three competitions (Super 14, Varsity Cup, and Under-19 Currie Cup). Using a two-dimensional scaled version of the field, the velocity and acceleration of the ball-carrier and tackler were measured at every 0.1 s to contact for 0.5 s. For front-on tackles, a significant difference (P < 0.05) between the ball-carrier (4.6 ± 1 m · s^–1) and tackler (7.1 ± 3.5 m · s^–1) was found at the 0.5 s time to contact interval in the Varsity Cup. For side-on tackles, differences between the two opposing players were found at 0.5 s (ball-carrier: 4.6 ± 1.7 m · s^–1; tackler: 3.1 ± 1.2 m · s^–1) and 0.4 s (ball-carrier: 6.3 ± 2.3 m · s^–1; tackler: 3.7 ± 1.6 m · s^–1) at Under-19 level. After 0.4 s, no significant differences (P > 0.05) were evident. Also, the ball-carrier's velocity over the 0.5 s was relatively stable compared with that of the tackler. Results suggest that tacklers adjust their velocity to reach a suitable relative velocity before making contact with the ball-carrier.     

The 1936 Olympic Games in Berlin: The Response of America's Black Press

Abstract

Eighty-seven female masters swimmers ranging in age from 20 to 69 were selected for a detailed study of their body composition and physiological responses at rest and during exercise. These women were then placed into two subsets, a highly trained group and a not highly trained group, on the basis of the frequency, duration, and intensity of swimming workouts. Significant differences were detected when comparing the highly trained and not highly trained subjects on measures of weight, body density, percent fat and lean body weight (p<.05). Significant differences which favored the highly trained group were also seen when comparing these same two groups for [Vdot]_E max, [Vdot]O₂ max (1/min), [Vdot]O₂ max (ml·kg^–1·min^–1), [Vdot]O₂ max (ml·kg·LBW^–1·min^–1), O₂ pulse (ml·kg^–1·beat^–1), and O₂ pulse (ml·kg·LBW^–1). Both the highly trained and not highly trained swimmers were considerably lower in percent fat than previously reported data for normal untrained women of similar ages. In both groups, however, percent fat across age levels within each training group showed significant increases at approximately 40 years of age (p<.05). In the highly trained swimmers, [Vdot]O₂ max (ml·kg^–1·min^–1) decreased at a mean rate of about 7% per decade, while in the not highly trained swimmers the decline was approximately 8% per decade. It appears that the rate of decline in [Vdot]O₂ max in women with aging may be independent of training status.     

Prolonged static stretching does not influence running economy despite changes in neuromuscular function

The aim of this study was to examine the acute effects of prolonged static stretching (SS) on running economy. Ten male runners (VO2(peak) 60.1 +/- 7.3 ml x kg(-1) x min(-1)) performed 10 min of treadmill running at 70% VO2(peak) before and after SS and no stretching interventions. For the stretching intervention, each leg was stretched unilaterally for 40 s with each of eight different exercises and this was repeated three times. Respiratory gas exchange was measured throughout the running exercise with an automated gas analysis system. On a separate day, participants were tested for sit and reach range of motion, isometric strength and countermovement jump height before and after SS. The oxygen uptake, minute ventilation, energy expenditure, respiratory exchange ratio and heart rate responses to running were unaffected by the stretching intervention. This was despite a significant effect of SS on neuromuscular function (sit and reach range of motion, +2.7 +/- 0.6 cm; isometric strength, -5.6% +/- 3.4%; countermovement jump height -5.5% +/- 3.4%; all P < 0.05). The results suggest that prolonged SS does not influence running economy despite changes in neuromuscular function.     

Extraordinary Animals and Expository Writing: Zoo in the Classroom

A zoo outreach program led to placing animals in classrooms where those animals became foci for numerous learning activities such as writing, observing, and care. Systematic debriefings suggested uniqueness to learning outcomes connected to zoo animals. Subsequent analysis of student writing indicated that students responded to situational interest by recording more observations, made use of more science facts, and used more science vocabulary when writing about unique animals (albino hedgehog, legless lizard) than ‘ordinary’ animals (rabbit, dove). The results are interpreted in terms of motivation, creating situational interest, and the familiarity of the schema available to the students. Policy implications are discussed.     

History of mathematics in secondary school teachers’ training: towards a nonviolent mathematics education

In the context of mathematics teachers’ training, the concept of dépaysement épistémologique (epistemological disorientation) emphasizes that the contact with the history of mathematics, particularly with the use of original sources, pushes aside commonplace students’ perspectives about the discipline and offers them a critical look towards mathematics’s historical, social and cultural aspects. Conceptually supported by the theory of objectivation, an emergent sociocultural theory in mathematics education, this study describes the dépaysement épistémologique lived by future mathematics teachers engaged in the reading of historical texts. A phenomenological approach allowed us to clarify various meanings associated with students’ lived experiences and a dialogical perspective provides a way to get these meanings in tension through a polyphonic narration. Our reading of this polyphonic narration suggests that dépaysement épistémologique associated with the reading of historical texts encouraged empathy from students towards the authors and their future learners, opening up the possibility for a nonviolent mathematics education.     

The invisible impact of educational research

Although there are policy calls for educational research to discover ‘what works’ and thereby inform decision making directly, the research literature argues instead for research to have a ‘conceptual’ impact on practice. Empirical studies also suggest that, when teachers use research, their use is conceptual; research influences the content and the process of their thinking, changing attitudes and perceptions and making educational decision making more intelligent. This study investigates the ways in which educational research has achieved impact on practice from the perspective of the researchers. A sample of highly-rated impact case studies in the UK’s research assessment exercise (REF2014) were subject to content analysis, using qualitative coding techniques. Analysis shows that most research is ‘invisible’ to education practitioners because it is embedded in educational policies, technologies, and services. This ‘invisible use’ is unlikely to realise the conceptual benefits claimed for research utilisation. If educational research is to make educational decision making more intelligent at its point of use, it will be necessary to re-think current notions of quality in research impact.     

Book reviews

Zwartjes, Otto, ed. La Sociedad andalusí y sus tradiciones literarias (Foro Hispánico, 7). Amsterdam: Rodopi, 1994.

Brincat, Joseph M. Malta 870–1054: Al‐Himyai's Account and its Linguistic Implications. Malta: Said International Ltd., 1995. 52pp.

Sells, Michael A. Mystical Languages of Unsaying. Chicago: The University of Chicago Press, 1994. 316 pp., US$18.95 (paperback), US$49.91 (cloth).

Diem, Werner, Arabische Geschäftsbriefe des 10. bis 14. Jahrhunderts aus der Österreichischen Nationalbibliothek in Wien (Documents Arabica Antiqua 1), 2 vols. Wiesbaden: Harrassowitz, 1995. Textband ix+518pp., Tafelband 76 plates.

Coope, Jessica A. The Martyrs of Cordoba: Community and Family Conflict in an Age of Mass Conversion. Lincoln: University of Nebraska Press, 1995. xvii+113 pp., US$ 25 (cloth).

Edwards, John. Religion and Society in Spain, c.1492 (Variorum Collected Studies Series: CS 520). Aldershot and Brookfield: Variorum, 1996. x+351 pp., US$ 97.00 (cloth).

Tolan, John Victor, ed. Medìeval Christian Perceptions of Islam. A Book of Essays (Garland Medieval Casebooks, Volume 10). New York and London: Garland Publishing, 1996. xxi+414 pp., US$60.00 (cloth).     

Showing and telling: The Difference that makes a Difference

In this article I attempt to clarify an essential difference between the ways in which pictures and words convey meaning. Despite the fact that the distinction between showing and telling is widely understood and clearly marked in ordinary language, it is often ignored when writers and researchers provide accounts of how children’s picturebooks work. As a result, such accounts are often unrealistic, providing distorted images of picturebook text. I briefly examine one such attempt to differentiate and characterise various types of picturebook and then conclude by showing how Anthony Browne exploits the distinction between showing and telling to create the atmosphere of uncertainty and mystery in his classic book Gorilla.