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Specific strength in sport climbing disciplines
Get PDFStrength of the upper limbs has been suggested to de a determinant in climbing performance (1). However, different kinds of assessments have provided contradictory results. Strength has been measured with general (handgrip) and specific (SCD, specific climbing dynamometer) tools. Isometric maximal voluntary contraction (MVC) and rate of force development (RFD) can be considered as outcomes. The SCD showed validity (correlated with lead performance n=38, r=-0.61, p<0.001)(2), reliability (Typical Error as CV was 8, 16% for SCD MVC and peak-RFD and ICC of 0.91, 0.82, respectively) (3) and internal responsiveness (effect size 1.44 in SCD peak-RFD) (4). Lead and Boulder are widespread disciplines in sport climbing. Boulder climbers showed higher values of MVC and pRFD compared to Lead climbers (5). Muscle fatigue (i.e. decrease in MVC and RFD parameters) can give further details in the importance of neuromuscular properties in sport climbing disciplines. The aim of this study was to examine muscle fatigue after Boulder and Lead activity.
Methods
Fourteen climbers (age 29 ± 10 yrs, height 176 ± 8 cm, weight 70 ± 7 kg, climbing level IRCRA scale moderate to advanced) participated in a simulated competition in Lead and Boulder. Before the measurement climbers were involved in a survey investigation. Participants were randomly assigned to a sequence Lead-Boulder or Boulder-Lead in a counterbalanced design with two conditions (i.e. Lead and Boulder) and washout (i.e. recovery) period of 4 hours. Specific strength (MVC and RFD) was measured with a SCD at baseline and after Boulder and Lead.
Results
Climbers perceived strength of the forearms to be important in boulder and lead (12 and 13% of the answers) performances and physical strength of higher importance in boulder compared to lead (34 and 42% of answers). MVC and pRFD at baseline were 7.2 ± 1.1 N/kg and 38.2 ± 8.6 N/kg/s. After boulder, MVC and pRFD were 6.8 ± 1.5 N/kg and 32.7 ± 10.3 N/kg/s, percentage differences -7.4 (90% CI ± 7.3) and -16.3 (90% CI ± 15). After lead MVC and pRFD were 6.4 ± 1.7 N/kg and 30 ± 11.3 N/kg/s, percentage differences -12.8 (90% CI ± 10.8) and -25.4 (90% CI ± 13).
Discussion
The decline in strength after Lead and Boulder simulation of competition confirms the occurrence of muscle fatigue. This study confirmed previous results attained after a Lead official competition and simulation for pRFD (-19%) and MVC (-6%) (2). The great decline in pRFD underlined the importance of rapidly exerting the strength (i.e. contact strength) during both disciplines.
Conclusion
Specific strength should be assessed with SCD. Rate of force development seams to be more appropriate compared to maximal voluntary contraction for investigating fatigue after climbing disciplines.
References
1. Watts, P.B., Eur J Appl Physiol, 2004. 91(4): 361-72.
2. Fanchini, M., et al. In 15th Annual Congress of ECSS. 2010. Antalya, Turkey
3. Fanchini M, et al. In 16th Annual Congress of Sport Science ECSS. 2011. Liverpool, UK.
4 Fanchini M, et al. In 2nd International Rock Climbing Research Congress 2014, Pontresina, Switzerland
5 Fanchini M et al. J Strength Cond Res,2013. 27(2): 310-31
Assessment of physical performance using GPS during competitive matches in youth elite soccer players
No full textThe aim of this study was to measure physical performance during official soccer competitions using Global Positioning System (GPS) technology. Sixteen youth professional soccer players (age 18±0.2 years, weight 70±7 kg, height 179±6 cm) from an Italian SerieA club were monitored over seven official matches with GPS (SPI-Pro X, GPSports). The high and very-high speed running distances (HSR, 14.4-19.7 and VHSR, >19.8 km/h, respectively) as well as the high metabolic
power distance (HPR, >20 W/kg) and the mean metabolic power (Pmet) were considered as indicators of physical performance. No time x position interactions were found (all P>0.05). A significant decrease in HSR, HPR and Pmet occurred through the game (all P<0.001). HSR was 33% lower in the last than in the first 15 min of the game (21.4 vs. 32.2 m/min, P=0.006), whereas HPR and Pmet were lower in the last four compared with the first two 15-min periods (all P<0.05).
Full-backs performed significantly higher VHSR (9.4 vs. 5.3 m/min, P=0.03) and Pmet (14.5 vs. 12.1 W/kg, P=0.046) and tended to have higher HPR (29.8 vs 21.1 m/min, P=0.054) compared with central defenders. No significant differences were observed between the other playing positions.
This is the first study to assess physical performance during official soccer match-play using GPS technology. The results show that high speed and power distances decreased throughout the game and were higher in full-backs compared with central defenders. Thus, GPS and its-related metabolic power measurements can be used as an additional tool to evaluate match physical performance
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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