Associations of total sedentary time,screen time and non-screen sedentary time with adiposity and physical fitness in youth: the mediating effect of physical activity

The aims of the present study were: i) to examine the associations of total accelerometer-based sedentary time (ST) and specific-domain self-reported ST (i.e., screen-based, educational-based, social-based, and other-based ST) with adiposity and physical fitness in youth; and ii) to analyse the mediation effect of physical activity (PA) on associations.

This study was conducted with 415 children (9.1 ± 0.4 years) and 853 adolescents (13.6 ± 1.6 years) in Spain during 2011–2012. Total ST and PA were assessed by accelerometry. Leisure-time spent in twelve sedentary behaviours was self-reported. Adiposity and physical fitness was measured following the ALPHA battery for youth.

Total accelerometer-based ST was positively associated with global adiposity score in children, and negatively associated with global physical fitness score in children and adolescents; but relationships were not independent of PA. PA mediated all associations of accelerometer-based and self-reported ST with adiposity or physical fitness in children. Conversely, screen-, educational-, social-, and other-based ST were negatively related to physical fitness in adolescents, independently of PA.

These findings give an impetus to developing effective strategies for specifically promoting PA in children and for increasing PA while reducing ST in adolescents in order to produce improvements on adiposity and physical fitness.     

Search for autonomy in motor task learning in physical education university students

The study focused on discovering the influence that an autonomous motor task learning programme had on the improvement of perceived competence, intrinsic regulation, incremental belief and motivational orientations. The study was performed with two groups of participants (n = 22 and n = 20) aged between 19 and 35 years. The instruments used were the incremental factor of the Conceptions of the Nature of Athletic Ability Questionnaire (CNAAQ-2), the Goal Orientation in Exercise Scale (GOES), the intrinsic regulation factor of the Behavioural Regulation in Exercise Questionnaire (BREQ-2), the perceived autonomy factor of the autonomy measurement scale (EMA) and the perceived competence factor of the Motives for Physical Activity Measure Revised Scale (MPAM-R). The questionnaires were handed out over 3 months in a weekly session with pre-test and post-test. The results showed that the use of an autonomy-based teaching programme increased perceived competence, intrinsic motivation, incremental ability belief and task-involving motivational orientation.     

Relationships between intrinsic motivation, physical self-concept and satisfaction with life: a longitudinal study

In this study, we examined the relationships between intrinsic motivation, physical self-concept, and satisfaction with life using cross-lagged panel models analysed via structural equation models. The sample consisted of 293 participants (148 men, 145 women) aged 18-70 years who performed diverse types of physical exercise. Three alternative models were tested. The data were better represented by a model in which physical self-concept mediates the relationships between intrinsic motivation and satisfaction with life. Specifically, the direct effects of intrinsic motivation on physical self-concept, and of physical self-concept on satisfaction with life were significant, with the amount of explained variance increasing over time. In conclusion, people who perform physical exercise regularly, and who have fun over time will tend to have a better physical self-perception and, consequently, more psychological well-being.     

Contribution of historical Spanish inventions to the knowledge of olive oil industrial heritage

This article presents new research, which has the objective of quantifying the knowledge produced by historical technological innovations in the field of olive oil industrial heritage. It studies inventions related to the mechanical processes of the extraction of olive oil between 1826 and 1966, which are recorded in the Historical Archive of the Spanish Patent and Trademark Office. It uses a new adaptation of the methodology of knowledge management (KM) defined by Nonaka and Takeuchi. We have obtained the knowledge value of each innovation according to the level of technological knowledge registered at the time, while distinguishing between the historical evolution of inventions relating to milling and those relating to pressing. In the first analysis, the results show a recession in the quantitative level of knowledge in the olive oil sector with respect to the technological potential of the time. However, when contrasted with the events relating to industrial heritage at the time, it is possible to account for this technological evolution and prove the validity of the methodology used. The results show that general evolution of the knowledge generated has decreased, particularly in the pressing process, although this is not the case in the milling process.     

Prediction of adult height in girls: the Beunen-Malina-Freitas method

The purpose of this study was to validate and cross-validate the Beunen-Malina-Freitas method for non-invasive prediction of adult height in girls. A sample of 420 girls aged 10-15 years from the Madeira Growth Study were measured at yearly intervals and then 8 years later. Anthropometric dimensions (lengths, breadths, circumferences, and skinfolds) were measured; skeletal age was assessed using the Tanner-Whitehouse 3 method and menarcheal status (present or absent) was recorded. Adult height was measured and predicted using stepwise, forward, and maximum R (2) regression techniques. Multiple correlations, mean differences, standard errors of prediction, and error boundaries were calculated. A sample of the Leuven Longitudinal Twin Study was used to cross-validate the regressions. Age-specific coefficients of determination (R (2)) between predicted and measured adult height varied between 0.57 and 0.96, while standard errors of prediction varied between 1.1 and 3.9 cm. The cross-validation confirmed the validity of the Beunen-Malina-Freitas method in girls aged 12-15 years, but at lower ages the cross-validation was less consistent. We conclude that the Beunen-Malina-Freitas method is valid for the prediction of adult height in girls aged 12-15 years. It is applicable to European populations or populations of European ancestry.     

Parental beliefs about child development and parental inferences about actions during child-rearing episodes

The way parents’ beliefs on child development support the elaboration of practical inferences during everyday child-rearing episodes was examined. We contrasted two models based respectively on the classical and the connectionist view of schema approaches. According to the classical view, parents activate preformed packages of beliefs in order to produce inferences whereas under the connectionist view, they activate the network of interconnected episodic traces that better fits the information provided by the situation. In the former case, the quality of the inferences depends on the activation of the proper schema whereas in the latter case it depends on the structure of the information given. Two experiments were designed in which parents holding a particular global belief about child development (either constructivism or environmentalism), were presented with a target couple with similar or different views with respect to them. In Experiment 1, constructivist parents bearing in mind the couple’s belief had to judge a set of words describing the couple’s image as parents, their educational goals as well as a number of sentences describing the couple’s child-rearing practices during hypothetical episodes. In Experiment 2, environmentalist parents had to judge the couple’s practices and the amount of information presented about the couple’s ideas as well as its plausibility were manipulated. The results indicate that the accuracy and speed in the production of inferences depends on the information presented in the task. When the information is embedded in episodes and a full, plausible and distinctive account of the couple’s belief are provided, then the production of inferences is performed faster and with more accuracy. The results are discussed in terms of the classical and connectionist views of schema approaches.