Differences in strength and speed demands between 4v4 and 8v8 small-sided football games

ABSTRACT

The aims of this study were (i) to characterise the acceleration demands of two different formats of small-sided game (SSG), i.e., 4v4 + goalkeepers (4v4 + GK) and 8v8 + goalkeepers (8v8 + GK); (ii) to analyse the correlation between performance in power-based tests and acceleration-based physical loading during the two different SSG formats and (iii) to analyse the neuromuscular-induced fatigue. Eighteen adult male footballers participated in the study (20.7 ± 1.0 years, 178 ± 5 cm and 71.4 ± 2.1 kg). Baseline measurements were obtained from countermovement jumps, 15 s repeated jumps and 5 and 15 m sprints. A total of 36 min was analysed for each SSG (4v4 + GK: two sets of 3 × 6 min, and 8v8 + GK: 2 × 18 min). Heart rate, blood lactate, perceived exertion and movement pattern (GPS) were analysed. Distances covered by very-high-intensity activities and very-high-speed running were lower in 4v4 + GK than in 8v8 + GK (effect sizes (ES) = ?0.69 ± 0.67 and ?1.04 ± 0.67, respectively; very likely), while accelerations and decelerations were higher in 4v4 + GK than in 8v8 + GK (ES = 1.13–1.52; almost certainly). Blood lactate concentrations were higher (ES = 1.40 ± 0.58; almost certainly) and players perceived themselves to be more tired (ES = 0.80–2.31; almost certainly) after 4v4 + GK than after 8v8 + GK. Sprint ability in 5 and 15 m tests decreased (ES = 0.87 ± 0.58 and 0.89 ± 0.58, respectively; almost certainly) only after 4v4 + GK. This SSG format appeared more demanding in relation to repetitions and fatigue development of muscle power-based actions than 8v8 + GK. It may therefore be logical to use the former type of SSG to target development of power-related football actions.     

Poor precompetitive sleep habits,nutrients’ deficiencies,inappropriate body composition and athletic performance in elite gymnasts

This study aimed to evaluate body composition, sleep, precompetitive anxiety and dietary intake on the elite female gymnasts’ performance prior to an international competition. Sixty-seven rhythmic gymnasts of high performance level were evaluated in relation to sport and training practice, body composition, sleep duration, daytime sleepiness by the Epworth Sleepiness Scale (ESS), sleep quality by the Pittsburgh Sleep Quality Index (PSQI), precompetitive anxiety by the Sport Competition Anxiety Test form A (SCAT-A) and detailed dietary intake just before an international competition. Most gymnasts (67.2%) suffered from mild daytime sleepiness, 77.6% presented poor sleep quality and 19.4% presented high levels of precompetitive anxiety. The majority of gymnasts reported low energy availability (EA) and low intakes of important vitamins including folate, vitamins D, E and K; and minerals, including calcium, iron, boron and magnesium (p?p?=?.001), sport practice (p?=?.024), number of daily training hours (p?=?.000), number of hours of training/week (p?=?.000), waist circumference (WC) (p?=?.008) and sleep duration (p?=?.005). However, it was negatively correlated with WC/hip circumference (p?=?.000), ESS (p?=?.000), PSQI (p?=?.042), SCAT-A (p?=?.002), protein g/kg (p?=?.028), EA (p?=?.002) and exercise energy expenditure (p?=?.000). High performance gymnasts presented poor sleep habits with consequences upon daytime sleepiness, sleep quality and low energy availability.     

Methodological-conceptual problems in the study of chimpanzees’ folk physics: How studies with adult humans can help

In three experiments, we examined humans’ folk physics (i.e., a naturally occurring and spontaneous understanding of the physical world), using variations of problems used to study chimpanzees’ folk physics. Presented with trap-tube problems in two experiments, adult humans showed an unnecessary bias to insert a stick into the end of the tube farthest from the reward to push it out the other end. When presented with trap-table problems with ineffective trapping holes, people unnecessarily avoided the side with the hole. The similarity of humans’ and chimpanzees’ behavior on these tasks highlights methodological and conceptual problems in studies of chimpanzees’ folk physics and suggests alternative explanations for their behavior.     

American influencies in Brazilian physical education: clues in the specialised periodical press (1932–1950)

This study investigates the American presence and influences in the physical education press to understand the way in which that presence influenced and contributed to the production of a sports culture in the first half of the twentieth century. As historical sources, the study uses periodicals in the field that were published in the period 1932–1950. As a theoretical frame of reference, it uses the repertoire of the New Cultural History in terms of strategy, tactics and devices. It is written in a narrative way, following Ginzburg's style, presenting data and contextualizing them with the historic scene. Clues enabled us to infer that the American presence, which was catalysed by the Brazilian Young Men's Christian Association (YMCA), sought to shape a sports culture from physical education and society. This effort reflected the yearning of Brazilian intellectuals for modernisation and an attempt at cultural colonisation by the government of the USA.     

Early intervention in Portugal: family support and benefits

This study investigated the support and benefits of early intervention (EI) in families with children with special needs. Data were gathered through a written questionnaire, ‘Family Benefits Inventory’, completed by 126 families with children with special needs supported by EI teams, with ages from six months to six years in Portugal. The global results obtained in this study allowed us to conclude that families considered that they obtained benefit from EI and received support most of the time in the different dimensions of the questionnaire. Furthermore, support given by an EI professional had a positive influence on families' perceptions regarding the benefits of EI.     

Development of mechanical engineering curricula at the University of Minho

The implementation of the Bologna protocol in the European Union has set new goals for the whole higher education system as: (a) a quality assessment for university courses; (b) a framework for the exchange of students and academics; and (c) an opportunity for changing the teaching/learning procedures and methodologies. Within the context, the mechanical engineering curricula at the University of Minho have been comprehensively formulated in order to meet these and future challenges and expectations. The whole process has been based upon various cornerstones: the legal framework for the higher education system; the introduction of new learning methodologies and an accurate survey and understanding of the existing strong and week points of the previous experience. For this purpose, a comprehensive evaluation has been carried out with former students and a detailed map has been formulated regarding their professional careers and experiences. Furthermore, a discussion has been carried out in order to define the mission of the graduate in mechanical engineering. In brief, such mission may be referred by his ability to participate in the wealth creation through technology based innovation. Within this context, the curriculum has been structured in order to meet such goals. In addition to strong foundations in physics and mathematics, new subjects are introduced into the curriculum. The whole education is based upon project development which stimulates the students' initiative, responsibility and their ability to integrate knowledge. Throughout the curriculum, students are enrolled into research projects developed in the department and it is expected that a few selected projects may be taken into a quasi industrial stage.     

德国在华战地邮政及加盖“KM”的清一次片

1900（庚子）年，中国华北平原爆发了大规模“扶清灭洋”的义和团运动。随即八国联军大肆入侵京津地区，史称“庚子事变”。     

Circadian Rhythms in Cognitive Processes: Implications for School Learning

Circadian variations have been found in cognitive processes, such as attention, working memory, and executive functions, which may explain oscillations in the performance of many tasks. These cognitive processes improve during the day and decrease during the night and early hours of the morning. Sleep deprivation further decreases these cognitive processes during daytime hours. This review analyses the recent findings on circadian rhythms in cognitive processes, as well as the implications of these rhythms for school learning.