Factors influencing physiological responses to small-sided soccer games     

Ermanno Rampinini  Franco M. Impellizzeri  Carlo Castagna  Grant Abt  Karim Chamari  Aldo Sassi 《Journal of sports sciences》2013,31(6):659-666

Abstract

The aim of this study was to examine the effects of exercise type, field dimensions, and coach encouragement on the intensity and reproducibility of small-sided games. Data were collected on 20 amateur soccer players (body mass 73.1 ± 8.6 kg, stature 1.79 ± 0.05 m, age 24.5 ± 4.1 years, [Vdot]O_2max 56.3 ± 4.8 ml · kg^?1 · min^?1). Aerobic interval training was performed during three-, four-, five- and six-a-side games on three differently sized pitches, with and without coach encouragement. Heart rate, rating of perceived exertion (RPE) on the CR10-scale, and blood lactate concentration were measured. Main effects were found for exercise type, field dimensions, and coach encouragement (P < 0.05), but there were no interactions between any of the variables (P > 0.15). During a six-a-side game on a small pitch without coach encouragement, exercise intensity was 84 ± 5% of maximal heart rate, blood lactate concentration was 3.4 ± 1.0 mmol · l^?1, and the RPE was 4.8. During a three-a-side game on a larger pitch with coach encouragement, exercise intensity was 91 ± 2% of maximal heart rate, blood lactate concentration was 6.5 ± 1.5 mmol · l^?1, and the RPE was 7.2. Typical error expressed as a coefficient of variation ranged from 2.0 to 5.4% for percent maximal heart rate, from 10.4 to 43.7% for blood lactate concentration, and from 5.5 to 31.9% for RPE. The results demonstrate that exercise intensity during small-sided soccer games can be manipulated by varying the exercise type, the field dimensions, and whether there is any coach encouragement. By using different combinations of these factors, coaches can modulate exercise intensity within the high-intensity zone and control the aerobic training stimulus.  相似文献   

Effects of concurrent training on interleukin-6, tumour necrosis factor-alpha and C-reactive protein in middle-aged men     

Cleiton Augusto Libardi  Giovana Verginia Souza  Arthur Fernandes GÁspari  Claudinei Ferreira Dos Santos  Sabrina Toffoli Leite  Rodrigo Dias 《Journal of sports sciences》2013,31(14):1573-1581

Abstract

The purpose of this study was to evaluate the effects of moderate- to high-intensity resistance and concurrent training on inflammatory biomarkers and functional capacity in sedentary middle-aged healthy men. Participants were selected on a random basis for resistance training (n = 12), concurrent training (n = 11) and a control group (n = 13). They performed three weekly sessions for 16 weeks (resistance training: 10 exercises with 3 × 8–10 repetition maximum; concurrent training: 6 exercises with 3 × 8–10 repetition maximum, followed by 30 minutes of walking or running at 55–85% [Vdot]O_2peak). Maximal strength was tested in bench press and leg press. The peak oxygen uptake ([Vdot]O_2peak) was measured by an incremental exercise test. Tumour necrosis factor-α, interleukin-6 and C-reactive protein were determined. The upper- and lower-body maximal strength increase for both resistance (+42.52%; +20.9%, respectively) and concurrent training (+28.35%; +21.5%, respectively) groups (P = 0.0001).[Vdot]O_2peak increased in concurrent training when comparing pre- and post-training (P = 0.0001; +15.6%). No differences were found in tumour necrosis factor-α and interleukin-6 for both groups after the exercise. C-reactive protein increased in resistance training (P = 0.004). These findings demonstrated that 16 weeks of moderate- to high-intensity training could improve functional capacity, but did not decrease inflammatory biomarkers in middle-aged men.  相似文献   

Changing attitudes and intentions related to doping: An analysis of individual differences in need for cognition     

Javier Horcajo  David Santos  Joshua J. Guyer  Lorena Moreno 《Journal of sports sciences》2013,31(24):2835-2843

ABSTRACT

Research has shown that athletes’ attitudes towards the use of banned performance-enhancing substances are reliable predictors of their intentions to use these substances, which in turn can be relevant predictors of their actual doping behaviours. Despite the important role played by attitudes and intentions in doping, research analysing how to change those attitudes and intentions is relatively scarce. The present study examined how individual differences in Need for Cognition (NC, Cacioppo & Petty, 1982) influenced doping-related attitude change and subsequent behavioural intentions. Participants were randomly assigned to read a persuasive message either against or in favour of legalising the use of several banned substances, including anabolic androgenic steroids (AAS) and Erythropoietin (EPO). In addition, participants completed the NC scale, and finally reported their attitudes and behavioural intentions regarding the legalisation proposal. As hypothesised, results showed that participants who received an anti-legalisation message had significantly more unfavourable attitudes towards the proposal than participants who received a pro-legalisation message, regardless of NC. However, as predicted, NC moderated the relationship between individuals’ attitudes and their intentions. That is, high-NC participants showed greater attitude-intention correspondence than low-NC participants.  相似文献   

Creatine supplementation does not decrease oxidative stress and inflammation in skeletal muscle after eccentric exercise     

Luciano A. Silva  Camila B. Tromm  Guilherme Da Rosa  Karoliny Bom  Thais F. Luciano  Talita Tuon 《Journal of sports sciences》2013,31(11):1164-1176

Abstract

Thirty-six male rats were used; divided into 6 groups (n = 6): saline; creatine (Cr); eccentric exercise (EE) plus saline 24 h (saline + 24 h); eccentric exercise plus Cr 24 h (Cr + 24 h); eccentric exercise plus saline 48 h (saline + 48 h); and eccentric exercise plus Cr 48 h (Cr + 48h). Cr supplementation was administered as a solution of 300 mg · kg body weight^?1 · day^?1 in 1 mL water, for two weeks, before the eccentric exercise. The animals were submitted to one downhill run session at 1.0 km · h^?1 until exhaustion. Twenty-four and forty-eight hours after the exercise, the animals were killed, and the quadriceps were removed. Creatine kinase levels, superoxide production, thiobarbituric acid reactive substances (TBARS) level, carbonyl content, total thiol content, superoxide dismutase, catalase, glutathione peroxidase, interleukin-1b (IL-1β), nuclear factor kappa B (NF-kb), and tumour necrosis factor (TNF) were analysed. Cr supplementation neither decreases Cr kinase, superoxide production, lipoperoxidation, carbonylation, total thiol, IL-1β, NF-kb, or TNF nor alters the enzyme activity of superoxide dismutase, catalase, and glutathione peroxides in relation to the saline group, respectively (P < 0.05). There are positive correlations between Cr kinase and TBARS and TNF-α 48 hours after eccentric exercise. The present study suggests that Cr supplementation does not decrease oxidative stress and inflammation after eccentric contraction.  相似文献   

A toy model that predicts the qualitative role of bar bend in a push jerk     

Aaron Santos  Norman E. Meltzer 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):345-359

In this work, we describe a simple coarse-grained model of a barbell that can be used to determine the qualitative role of bar bend during a jerk. In simulations of this model, we observed a narrow time window during which the lifter can leverage the elasticity of the bar in order to lift the weight to a maximal height. This time window shifted to later times as the weight was increased. In addition, we found that the optimal time to initiate the drive was strongly correlated with the time at which the bar had reached a maximum upward velocity after recoiling. By isolating the effect of the bar, we obtained a generalized strategy for lifting heavy weight in the jerk.  相似文献   

Heat and Kinetic Theory in 19th-Century Physics Textbooks: The Case of Spain     

Vaquero  Joseb M.  Santos  Andrebs 《Science & Education》2001,10(3):307-319

Spain was a scientifically backward country in the early 19th century. The causes were various political events, the War of Independence, and the reignof Fernando VII. The introduction of contemporary physics into textbooks was thereforea slow process. An analysis of the contents of 19th-century Spanish textbooks is presented here, centred on imponderable fluids, the concept of energy, the mechanicaltheory of heat, and the kinetic theory of gases.  相似文献   

Learning design and learning analytics in mobile and ubiquitous learning: A systematic review     

Gerti Pishtari  María J. Rodríguez-Triana  Edna M. Sarmiento-Márquez  Mar Pérez-Sanagustín  Adolfo Ruiz-Calleja  Patricia Santos  Luis P. Prieto  Sergio Serrano-Iglesias  Terje Väljataga 《British journal of educational technology : journal of the Council for Educational Technology》2020,51(4):1078-1100

Mobile and Ubiquitous Learning (m/u-learning) are finding an increasing adoption in education. They are often distinguished by hybrid learning environments that encompass elements of formal and informal learning, in activities that happen in distributed settings (indoors and outdoors), across physical and virtual spaces. Despite their purported benefits, these environments imply additional complexity in the design, monitoring and evaluation of learning activities. The research literature on learning design (LD) and learning analytics (LA) has started to deal with these issues. This paper presents a systematic literature review of LD and LA, in m/u-learning. Apart from providing an overview of the current research in the field, this review elicits elements of common ground between both communities, as shown by the similar learning contexts and complementary research contributions, and based on the research gaps, proposes to: address m/u-learning beyond higher education settings, reinforce the connection between physical and virtual learning spaces, and more systematically align LD and LA processes.  相似文献   

The development of clinical reasoning skills: A major objective of the anatomy course     

Rodrigo E. Elizondo‐Omaña  Santos Guzmán López 《Anatomical sciences education》2008,1(6):267-268

Traditional medical school curricula have made a clear demarcation between the basic biomedical sciences and the clinical years. It is our view that a comprehensive medical education necessarily involves an increased correlation between basic science knowledge and its clinical applications. A basic anatomy course should have two main objectives: for the student to successfully gain a solid knowledge base of human anatomy and to develop and hone clinical reasoning skills. In a basic anatomy course, clinical case discussions based on underlying anatomic anomalies or abnormalities are the major means to teach students clinical reasoning skills. By identifying, classifying, and analyzing the clinical data given, a student learns to methodically approach a clinical case and formulate plausible diagnoses. Practicing and perfecting clinical problem‐solving skills should be a major objective of the anatomy curriculum. Such clinical reasoning skills are indeed crucial for the successful and expert practice of medicine. Anat Sci Ed 1:267–268, 2008. © 2008 American Association of Anatomists.  相似文献   

Hybrid Deterministic Views About Genes in Biology Textbooks: A Key Problem in Genetics Teaching     

Vanessa Carvalho dos Santos  Leyla Mariane Joaquim  Charbel Ni?o El-Hani 《Science & Education》2012,21(4):543-578

A major source of difficulties in promoting students’ understanding of genetics lies in the presentation of gene concepts and models in an inconsistent and largely ahistorical manner, merely amalgamated in hybrid views, as if they constituted linear developments, instead of being built for different purposes and employed in specific contexts. In this paper, we report the results of a study about how textbooks can provide the grounds for the students’ construction of such hybrid views about genes. These views are a key problem in genetics teaching, because they make it more difficult that students properly understand this central biological concept and strengthen genetic deterministic ideas, which characterize a widespread discourse about genes in the public opinion. We analyzed 18 textbooks using categorical content analysis, employing categories derived from the literature addressing the historical development of gene models and concepts. Our findings indicate that the analyzed textbooks do convey hybrid views about genes, with no correspondence to scientific models related to this biological concept. These views reinforce genetic deterministic discourses and may lead students to serious misunderstandings about the nature of genes and their role in living systems, with consequences to future learning about genetics.  相似文献   

Intellectual deficits in Brazilian victimized children and adolescents: A psychosocial problem?     

PA de Oliveira  GK Scarpari  B Dos Santos  S Scivoletto 《Child abuse & neglect》2012,36(7-8):608-610

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