Low-Load Blood-Flow Restriction Exercise to Failure and Nonfailure and Myoelectric Activity: A Meta-Analysis.

OBJECTIVE: To compare the short- and long-term effects of low-load resistance training with blood-flow restriction (LL-BFR) versus low- (LL-RT) or high- (HL-RT) load resistance training with free blood flow on myoelectric activity and investigate the differences between failure (exercise performed to volitional failure) and nonfailure (exercise not performed to volitional failure) protocols. DATA SOURCES: We identified sources by searching the MEDLINE, PubMed, CINAHL, Web of Science, CENTRAL, Scopus, SPORTDiscus, and PEDro electronic databases. STUDY SELECTION: We screened the titles and abstracts of 1048 articles using our inclusion criteria. A total of 39 articles were selected for further analysis. DATA EXTRACTION: Two reviewers independently assessed the methodologic quality of each study and extracted the data. A meta-analytic approach was used to compute standardized mean differences (SMDs) ± 95% CIs. Subgroup analyses were conducted for both failure and nonfailure protocols. DATA SYNTHESIS: The search identified 39 articles that met the inclusion criteria. Regarding the short-term effects, LL-BFR increased muscle excitability compared with LL-RT during nonfailure protocols (SMD = 0.61; 95% CI = 0.34, 0.88), whereas HL-RT increased muscle excitability compared with LL-BFR during failure (SMD = -0.61; 95% CI = -1.01, -0.21) and nonfailure (SMD = -1.13; 95% CI = -1.94, -0.33) protocols. Concerning the long-term effects, LL-BFR increased muscle excitability compared with LL-RT during exercises performed to failure (SMD = 1.09; 95% CI = 0.39, 1.79). CONCLUSIONS: Greater short-term muscle excitability levels were observed in LL-BFR than in LL-RT during nonfailure protocols. Conversely, greater muscle excitability was present during HL-RT than LL-BFR, regardless of volitional failure. Furthermore, LL-BFR performed to failure increased muscle excitability in the long term compared with LL-RT.

Factors Affecting Voluntary Self-Isolation Behavior to Cope with a Pandemic: Empirical Evidence from Colombia vs. Spain in Times of COVID-19.

Global pandemics are not a new phenomenon. They have occurred at different points in time and can be of different scales. COVID-19 appeared in 2020 and its spread has reached more than 60 countries worldwide. This research aims to analyze voluntary self-isolation behavior used to cope with the COVID-19 pandemic. As part of this study, we carried out sampling in Colombia and Spain, which share similar cultural characteristics but which have substantial social and economic differences. A multi-group model was used to test the application of the theory of planned behavior and the theory of reasoned action in order to analyze self-isolation behavior. The results show that there are differences in self-isolation behavior between both countries, especially with regard to attitudes towards self-isolation and volitional behavior.

O olhar estereoscópico para a ontogênese: desafiando o professor / The stereoscopic look at ontogenesis: challenging the teacher

O presente artigo tem como objetivo examinar como é possível ao professor - ou ao adulto-educador - estruturar um sistema de meios culturais conjugado com a idade psicológica da criança que possa operar sobre a zona de desenvolvimento iminente da criança. Para tanto, analisa-se o potencial metodológico da abordagem histórico-cultural de Vigotski para o diagnóstico e a promoção do desenvolvimento psíquico de crianças no início da vida escolar. Argumenta-se que, para o diagnóstico do desenvolvimento e a definição de estratégia do trabalho corretivo, é importante manter um olhar estereoscópico em que os eixos das coordenadas da visão ampla da criança sejam: o conteúdo da relação de convivência com os adultos e coetâneos, as especificidades da neoformação psicológica da idade como o conteúdo da vontade e do desenvolvimento cultural e, finalmente, a função psíquica central e a atividade-guia. São descritos dois exemplos que permitem indicar os aspectos corretivos centrais do adulto-educador e delinear prognósticos.(AU)

Abstract This article aims to examine how it is possible for the teacher - or the adult educator - to structure a system of cultural media combined with the child's psychological age that can operate on the child's imminent development zone. So, the methodological potential of Vygotsky's historical-cultural approach to the diagnosis and promotion of children's psychic development at the beginning of school life is analyzed. It is argued that, for the diagnosis of development and the definition of corrective work strategy, it is important to maintain a stereoscopic view according to which the axes of the child's broad view coordinates are: the content of the living relationship with adults and contemporaries, the specifics of the psychological neoformation of age as the content of will and cultural development, and finally the central psychic function and guiding activity. Two examples are described that allow us to indicate the central corrective aspects of the adult educator and to outline prognoses.(AU)

Translational Science: How experimental research has contributed to the understanding of spontaneous Physical Activity and Energy Homeostasis

Abstract Spontaneous physical activity (SPA) consists of all daily living activities other than volitional exercise (e.g. sports and fitness-related activities). SPA is an important component of energy expenditure and may protect from overweight and obesity. Little is known about the biological regulation of SPA, but animal researchhas contributedsignificantly to expand our knowledge in this field. Studies in rodents have shown that SPA is influenced by nutrients and volitional exercise. High-fat diet seems to decrease SPA, which contributes to weigh gain. Volitional exercisemayalso reduce SPA, helping to explain the commonly reported low efficiency of exercise to cause weight loss, and highlighting the need to finda volume/intensity of exercise to maximize total daily energy expenditure. Animal studieshave also allowed for the identification of some brain areas and chemical mediatorsinvolved in SPA regulation. These discoveries could enable the development of new therapeutics aiming to enhance SPA.(AU)