Circadian rhythm effect on physical tennis performance in trained male players

To determine the effect of circadian rhythm on neuromuscular responses and kinematics related to physical tennis performance, after a standardised warm-up, 13 highly competitive male tennis players were tested twice for serve velocity/accuracy (SVA), countermovement vertical jump (CMJ), isometric handgrip strength (IS), agility T-test (AGIL) and a 10-m sprint (10-m RUN). In a randomised, counter-balance order, tennis players underwent the test battery twice, either in the morning (i.e., AM; 9:00 h) and in the afternoon (i.e., PM; 16:30 h). Paired t-tests were used to analyse differences due to time-of-day in performance variables. Comparison of morning versus afternoon testing revealed that SVA (168.5 ± 6.5 vs. 175.2 ± 6.1 km · h^?1; P = 0.003; effect size [ES] = 1.07), CMJ (32.2 ± 0.9 vs. 33.7 ± 1.1 cm; P = 0.018; ES = 1.46), AGIL (10.14 ± 0.1 vs. 9.91 ± 0.2 s; P = 0.007; ES = 1.23) and 10-m RUN time (1.74 ± 0.1 vs. 1.69 ± 0.1 s; P = 0.021; ES = 0.67) were significantly blunted during the morning testing. However, IS was not affected by time-of-day (P = 0.891). Thus, tennis performance may be reduced when competing in the morning in comparison to early evening. Therefore, coaches and tennis players should focus on schedule the SVA, power, speed and agility training sessions in the afternoon.     

Computerized Agility Training Improves Change-of-Direction and Balance Performance Independently of Footwear in Young Adults

Understanding the effects of training in different footwear on sporting performance would be useful to coaches and athletes. Purpose: This study compared the effects of computerized agility training using 3 types of footwear on change-of-direction and balance performance in young adults. Method: Thirty recreationally active young adults (M_age = 22.8 ± 3.1 years; M_height = 1.71 ± 0.7 m; M_bodymass = 73.4 ± 10.3 kg) were randomly assigned to a 6-week computerized agility training intervention in 1 of 3 footwear groups (n = 10/group): barefoot, minimal footwear, or traditional shoes. Participants had no previous barefoot or minimal-footwear training experience. Dependent variables included change-of-direction test time to completion, Star Excursion Balance Test, and single-leg stability evaluation. Testing was performed at the start of the training program, after 2 weeks, after 4 weeks, and at the end of the training program. Results: No group or time interactions were found for any of the dependent variables. Time main effects were observed for the performance measures of change of direction, Star Excursion, and single-leg-with-eyes-open stability evaluation. Participants improved in all 3 tests as early as 2 weeks into the intervention, with improvements continuing through the entire 6-week intervention. Conclusions: The lack of interaction and footwear effects suggests that agility and balance improvements during foot agility training are independent of footwear in a recreationally active young-adult population. Computerized agility training improves change-of-direction and balance performance within 2 weeks of training implementation. Future studies should consider footwear training effects in different populations, including frail older adults and athletes.     

Influence of Session Context on Physical Activity Levels Among Russian Girls During a Summer Camp

Purpose: This study investigated the effect of summer camp session context on Russian girls’ physical activity (PA). Method: Girls (n = 32, M_age = 10.7 years, SD = 0.6 years) from a resident summer camp taking place in the Vologda Region of Russia were exposed to 1 session context/day (i.e., free play, organized with no choice, organized with choice) on Wednesday, Thursday, and Friday for 3 weeks, with the context order counterbalanced across the 3 weeks. The organized session sport/game changed weekly. The primary outcome was accelerometer-assessed PA. Repeated-measures mixed models were used to analyze all outcome data. Results: Findings showed that girls spent a greater percentage of session time (%time) in moderate-to-vigorous PA (p < .001; effect sizes between free play and organized with no choice and organized with choice, respectively = .60, .42) and moderate PA (p < .001; effect size = .57, .39) and a lower %time in light PA (p < .001; effect size = .55, .52) in organized PA contexts compared with free play. Conclusions: This study provides novel findings in a Russian setting, suggesting that a well-planned, organized camp session can elicit higher PA levels in girls, relative to a free-play session.     

Der Sportwissenschaftler als Unternehmer im Wissensmarkt

Creative ideas are the driving force behind knowledge production, the producers of which are generally domesticated at universities for the purposes of ensuring the methodological credibility of the knowledge produced, in order to minimise the impact of chance in the creation of new knowledge. The status of producers is determined by indicators designed to simulate the demand for knowledge, precipitate a quantitative and qualitative comparison of elements which are not comparable, and establish legitimacy for the means of control used. Furthermore, incentives for competitive sport research and the symbolic recognition of scientists via sport practice play a particular role for knowledge production in sports science. In order to compensate for the practical world’s unwillingness to pay for sports science expertise relevant to competitive sport, the German Federal Institute of Sports Science (BISp) functions as a simulator of demand for knowledge generated by universities, while the Institute for Applied Training Science with its services exclusively available to umbrella organisations limits the range of incentives to produce (competitive) sporting knowledge. Sports scientists are thus faced with a market situation which favours routine research and standard methods, creates legitimacy at a central level, does not necessarily tackle actual issues faced by (competitive) athletes, stimulates demand for monitoring services, and all in all leaves monoculture-driven gaps which could most likely only be avoided by advocating and applying individual scope for action throughout the research ethos.     

An interview with Marie-José Mondzain: what is an image?

ABSTRACT

Marie-Jose Mondzain is one of the major philosophers writing about image, iconography, and representation today. In this interview, she discusses a few of the central ideas in her approach to and thinking about the nature of image and image-making as they bear upon the emergence of subjectivity and visibility in general. According to Mondzain, images are not visual objects we may or may not see; rather they are the site where the visible and its invisibility crisscross each other in opening the field of presence. Images, as Mondzain says in the interview, are cracks or leaks in being. They are where lights first come in and where man and beings are born to each other in their being-in-the world, that is, in their truth. Moving beyond historical and theoretical reflections, Mondzain turns to discuss things and scenes of mass media of late, addressing issues of pleasure, anxiety, desire, and the like, wherein ideologies, power, and the lure of images can be seen to intersect with our everyday life that has become irrevocably one of passive mobility. To the point at every turn, her answers to questions in this interview provide a glimpse to her forceful thinking and insights.     

Boundary-Work in the Health Research Field: Biomedical and Clinician Scientists’ Perceptions of Social Science Research

Funding agencies in Canada are attempting to break down the organizational boundaries between disciplines to promote interdisciplinary research and foster the integration of the social sciences into the health research field. This paper explores the extent to which biomedical and clinician scientists’ perceptions of social science research operate as a cultural boundary to the inclusion of social scientists into this field. Results indicated that cultural boundaries may impede social scientists’ entry into the health research field through three modalities: (1) biomedical and clinician scientists’ unfavourable and ambivalent posture towards social science research; (2) their opposition to a resource increase for the social sciences; and (3) clinician scientists procedural assessment criteria for social science. The paper also discusses the merits and limitations of Tom Gieryn’s concept of boundary-work for studying social dynamics within the field of science.

‘We Have to Go Where the Money Is’—Dilemmas in the Role of Nutrition Scientists: An Interview Study

In Western societies scientists are increasingly expected to seek media exposure and cooperate with industry. Little attention has been given to the way such expectations affect the role of scientific experts in society. To investigate scientists’ own perspectives on these issues eight exploratory, in-depth interviews were conducted in Denmark with reputable nutrition scientists. Additionally, eight interviews were held with ‘key informants’ from the field of nutrition policy. It was found that nutrition scientists experience two dilemmas: first, between their aspiration to make a collective impact on public health and the powerful incentives of each to appear frequently in the media with new messages; second, between their need to cooperate with the food industry for financial reasons and their fear that this may compromise their independence and scientific integrity. It is argued that the dilemmas identified in this study should be dealt with openly by the relevant groups of scientists.     

How to be Real and Conventional: A Discussion of the Quality Criteria of Official Statistics

Are the categories used to study the social world and acting on it “real” or “conventional”? An empirical answer to that question is given by an analysis of the debates about the “quality” of statistics produced by the European National Institues of statistics in the 1990s. Six criteria of quality were then specified: relevance, accuracy, timeliness, accessibility, comparability and coherence. How do statisticians and users of statistics deal with the tension produced by their objects being both “real” (they exist before their measurement) and “conventionally constructed” (they are in a way, created by these conventions)? In particular, the technical and sociological distinction between the criteria of relevance and accuracy implies a realistic interpretation, desired by users, but that is nonetheless problematic.     

Rethinking Polanyi’s Concept of Tacit Knowledge: From Personal Knowing to Imagined Institutions

Half a century after Michael Polanyi conceptualised ‘the tacit component’ in personal knowing, management studies has reinvented ‘tacit knowledge’—albeit in ways that squander the advantages of Polanyi’s insights and ignore his faith in ‘spiritual reality’. While tacit knowing challenged the absurdities of sheer objectivity, expressed in a ‘perfect language’, it fused rational knowing, based on personal experience, with mystical speculation about an un-experienced ‘external reality’. Faith alone saved Polanyi’s model from solipsism. But Ernst von Glasersfeld’s radical constructivism provides scope to rethink personal tacit knowing with regard to ‘other people’ and the intersubjectively viable construction of ‘experiential reality’. By separating tacit knowing from Polanyi’s metaphysical realism and drawing on Benedict Anderson’s concept of ‘imagined communities’, it is possible to conceptualise ‘imagined institutions’ as the tacit dimension of power that shapes human interaction. Whereas Douglass North claimed institutions could be reduced to rules, imagined institutions are known in ways we cannot tell.