Rethinking fat as a fuel for endurance exercise

Abstract

A key element contributing to deteriorating exercise capacity during physically demanding sport appears to be reduced carbohydrate availability coupled with an inability to effectively utilize alternative lipid fuel sources. Paradoxically, cognitive and physical decline associated with glycogen depletion occurs in the presence of an over-abundance of fuel stored as body fat that the athlete is apparently unable to access effectively. Current fuelling tactics that emphasize high-carbohydrate intakes before and during exercise inhibit fat utilization. The most efficient approach to accelerate the body’s ability to oxidize fat is to lower dietary carbohydrate intake to a level that results in nutritional ketosis (i.e., circulating ketone levels >0.5 mmol/L) while increasing fat intake for a period of several weeks. The coordinated set of metabolic adaptations that ensures proper interorgan fuel supply in the face of low-carbohydrate availability is referred to as keto-adaptation. Beyond simply providing a stable source of fuel for the brain, the major circulating ketone body, beta-hydroxybutyrate, has recently been shown to act as a signalling molecule capable of altering gene expression, eliciting complementary effects of keto-adaptation that could extend human physical and mental performance beyond current expectation. In this paper, we review these new findings and propose that the shift to fatty acids and ketones as primary fuels when dietary carbohydrate is restricted could be of benefit for some athletes.     

The Undergraduate Research Student Self-Assessment (URSSA): Validation for Use in Program Evaluation

This article examines the validity of the Undergraduate Research Student Self-Assessment (URSSA), a survey used to evaluate undergraduate research (UR) programs. The underlying structure of the survey was assessed with confirmatory factor analysis; also examined were correlations between different average scores, score reliability, and matches between numerical and textual item responses. The study found that four components of the survey represent separate but related constructs for cognitive skills and affective learning gains derived from the UR experience. Average scores from item blocks formed reliable but moderate to highly correlated composite measures. Additionally, some questions about student learning gains (meant to assess individual learning) correlated to ratings of satisfaction with external aspects of the research experience. The pattern of correlation among individual items suggests that items asking students to rate external aspects of their environment were more like satisfaction ratings than items that directly ask about student skills attainment. Finally, survey items asking about student aspirations to attend graduate school in science reflected inflated estimates of the proportions of students who had actually decided on graduate education after their UR experiences. Recommendations for revisions to the survey include clarified item wording and increasing discrimination between item blocks through reorganization.Undergraduate research (UR) experiences have long been an important component of science education at universities and colleges but have received greater attention in recent years, as they have been identified as important ways to strengthen preparation for advanced study and work in the science fields, especially among students from underrepresented minority groups (Tsui, 2007 ; Kuh, 2008 ). UR internships provide students with the opportunity to conduct authentic research in laboratories with scientist mentors, as students help design projects, gather and analyze data, and write up and present findings (Laursen et al., 2010 ). The promised benefits of UR experiences include both increased skills and greater familiarity with how science is practiced (Russell et al., 2007 ). While students learn the basics of scientific methods and laboratory skills, they are also exposed to the culture and norms of science (Carlone and Johnson, 2007 ; Hunter et al., 2007 ; Lopatto, 2010 ). Students learn about the day-to-day world of practicing science and are introduced to how scientists design studies, collect and analyze data, and communicate their research. After participating in UR, students may make more informed decisions about their future, and some may be more likely to decide to pursue graduate education in science, technology, engineering, and mathematics (STEM) disciplines (Bauer and Bennett, 2003 ; Russell et al., 2007 ; Eagan et al. 2013 ).While UR experiences potentially have many benefits for undergraduate students, assessing these benefits is challenging (Laursen, 2015 ). Large-scale research-based evaluation of the effects of UR is limited by a range of methodological problems (Eagan et al., 2013 ). True experimental studies are almost impossible to implement, since random assignment of students into UR programs is both logistically and ethically impractical, while many simple comparisons between UR and non-UR groups of students suffer from noncomparable groups and limited generalizability (Maton and Hrabowski, 2004 ). Survey studies often rely on poorly developed measures and use nonrepresentative samples, and large-scale survey research usually requires complex statistical models to control for student self-selection into UR programs (Eagan et al., 2013 ). For smaller-scale program evaluation, evaluators also encounter a number of measurement problems. Because of the wide range of disciplines, research topics, and methods, common standardized tests assessing laboratory skills and understandings across these disciplines are difficult to find. While faculty at individual sites may directly assess products, presentations, and behavior using authentic assessments such as portfolios, rubrics, and performance assessments, these assessments can be time-consuming and not easily comparable with similar efforts at other laboratories (Stokking et al., 2004 ; Kuh et al., 2014 ). Additionally, the affective outcomes of UR are not readily tapped by direct academic assessment, as many of the benefits found for students in UR, such as motivation, enculturation, and self-efficacy, are not measured by tests or other assessments (Carlone and Johnson, 2007 ). Other instruments for assessing UR outcomes, such as Lopatto’s SURE (Lopatto, 2010 ), focus on these affective outcomes rather than direct assessments of skills and cognitive gains.The size of most UR programs also makes assessment difficult. Research Experiences for Undergraduates (REUs), one mechanism by which UR programs may be organized within an institution, are funded by the National Science Foundation (NSF), but unlike many other educational programs at NSF (e.g., TUES) that require fully funded evaluations with multiple sources of evidence (Frechtling, 2010 ), REUs are generally so small that they cannot typically support this type of evaluation unless multiple programs pool their resources to provide adequate assessment. Informal UR experiences, offered to students by individual faculty within their own laboratories, are often more common but are typically not coordinated across departments or institutions or accountable to a central office or agency for assessment. Partly toward this end, the Undergraduate Research Student Self-Assessment (URSSA) was developed as a common assessment instrument that can be compared across multiple UR sites within or across institutions. It is meant to be used as one source of assessment information about UR sites and their students.The current research examines the validity of the URSSA in the context of its use as a self-report survey for UR programs and laboratories. Because the survey has been taken by more than 3400 students, we can test some aspects of how the survey is structured and how it functions. Assessing the validity of the URSSA for its intended use is a process of testing hypotheses about how well the survey represents its intended content. This ongoing process (Messick, 1993 ; Kane, 2001 ) involves gathering evidence from a range of sources to learn whether validity claims are supported by evidence and whether the survey results can be used confidently in specific contexts. For the URSSA, our method of inquiry focuses on how the survey is used to assess consortia of REU sites. In this context, survey results are used for quality assurance and comparisons of average ratings over years and as general indicators of program success in encouraging students to pursue graduate science education and scientific careers. Our research questions focus on the meaning and reliability of “core indicators” used to track self-reported learning gains in four areas and the ability of numerical items to capture student aspirations for future plans to attend graduate school in the sciences.     

Breaking the Cycle: Future Faculty Begin Teaching with Learner-Centered Strategies after Professional Development

The availability of reliable evidence for teaching practices after professional development is limited across science, technology, engineering, and mathematics disciplines, making the identification of professional development “best practices” and effective models for change difficult. We aimed to determine the extent to which postdoctoral fellows (i.e., future biology faculty) believed in and implemented evidence-based pedagogies after completion of a 2-yr professional development program, Faculty Institutes for Reforming Science Teaching (FIRST IV). Postdocs (PDs) attended a 2-yr training program during which they completed self-report assessments of their beliefs about teaching and gains in pedagogical knowledge and experience, and they provided copies of class assessments and video recordings of their teaching. The PDs reported greater use of learner-centered compared with teacher-centered strategies. These data were consistent with the results of expert reviews of teaching videos. The majority of PDs (86%) received video ratings that documented active engagement of students and implementation of learner-centered classrooms. Despite practice of higher-level cognition in class sessions, the items used by the PDs on their assessments of learning focused on lower-level cognitive skills. We attributed the high success of the FIRST IV program to our focus on inexperienced teachers, an iterative process of teaching practice and reflection, and development of and teaching a full course.     

How Custom Agents Really Detect Lies

Research has found discrepancies among folk beliefs about lie detection, deception cue utility, and retrospective accounts of detected lies. Elite customs agents (N = 37) were surveyed regarding their overall beliefs about how to detect lies (general strategy), their opinions about best practices (best strategy), and about a successfully detected lie (actual strategy). Responses were coded in three nonexclusive broad categories: (a) behavioral cues, (b) communication content and evidence, and (c) interactive-questioning approaches. Behavioral cues, especially nonverbal cues, were listed most frequently as general beliefs. Opinions about the best approach were evenly split across the three categories. Communication content and evidence was the most frequently reported actual detection method and was mentioned in 97% of the responses. The results are discussed in relation to Truth-Default Theory and their implications for lie detection practice.     

INTERNAL FACTOR STRUCTURE AND CONVERGENT VALIDITY EVIDENCE: THE SELF‐REPORT VERSION OF SELF‐REGULATION STRATEGY INVENTORY

Using a sample of 348 middle school students, we gathered evidence regarding the internal consistency of scores, as well as the internal factor structure and convergent validity evidence for inferences from a self‐report questionnaire called the Self‐Regulation Strategy Inventory–Self Report. Confirmatory factor analysis revealed that the fit indexes for a hierarchical model (composite, three factors) and a single‐level, three‐factor model were highly similar but mixed. Respecification of the hierarchical model based on conceptual overlap of items led to substantial improvement in the overall fit of the model, as indicated by the root mean square error of approximation, chi‐square/df, and the comparative fit index. Correlational analyses also provided strong convergent validity evidence, as the three subscales exhibited statistically significant relations with four motivation beliefs (i.e., self‐efficacy, perceived instrumentality, task interest, perceived responsibility) and two distinct markers of regulation‐related behaviors (i.e., teacher ratings, office discipline referrals).     

Personality Type and Participation in Networked Learning Environments

For networked learning environments, it is necessary to consider different aspects of this environment, such as the collaborative environment, the nature of activities and resources, the technological environment and the learner's characteristics, if quality learning is to take place online. This paper focuses on one aspect of the learner's characteristics; that of personality type as determined using the Myers Briggs Type Indicator (Myers, 1984). It investigates the relationship between personality type and a student's participation (both passive and active) within a networked learning environment using asynchronous threaded discussion for a university course run both online and face-to-face. Qualitative results show patterns in student attitudes to participation related to personality type, particularly on the dimensions of introversion/extroversion, sensing/intuition and thinking/feeling. The paper also discusses implications of the findings in relation to the development of the networked learning environment, to ensure better online participation from all students. L’importance des types de personnalité dans la participation dans des environnements d’apprentissage en réseau. Pour les environnements d’apprentissage en réseau Net, il faut considérer différents aspects de cet environnement coopératif, la nature des activités et des sources, l’environnement technologique et les caractéristiques de l’apprenant si l’on veut en ligne obtenir un apprentissage de qualité. Cet article se concentre sur un aspect des caractéristiques de l’apprenant, celui du type de personnalité défini dans le Myer Briggs Type Indicator (Myers, 1984). Il étudie la relation entre le type de personnalité et la participation d’un étudiant (passive et active) dans un environnement d’apprentissage basé sur le Net utilisant une discussion filetée asynchrone our un cours d’université mené face À face et en ligne. Les résultats qualitatifs montrent des modéles dans

l’attitude des étudiant quant À la participation liée au type de personnalité, particulièrement sur les dimensions de l’introversion/extroversion, de la sensation/intuition et de la pensée/sentiments. L’article discute aussi des implications des

résultats en relation avec le développement de l’environnement de l’apprentissage en réseau, pur assurer une meilleure

participation en ligne de la part de tous les étudiants. Persönlichkeitstyp und Partizipation in vernetzten Lernumgebungen. Bei vernetzten Lernumgebungen müssen unterschiedliche Aspekte dieser Umgebung bedacht werden, so z.B. der

gemeinschaftliche Bereich, die Art von Aktivitäten und Ressourcen, die technischen Gegebenheiten und die Charakteristika der Lernenden, wenn erstklassiges Lernen auch online möglich werden soll. Dieser Beitrag beschränkt sich auf einen charakteristischen Aspekt des Lerners: seinen Persönlichkeitstyp unter Benutzung des Myers Briggs Type Indicator (Myers, 1984). Es untersucht die Beziehung zwischen dem Persönlichkeitstyp und der Teilhabe (aktiv und passiv) eines Studenten

innerhalb einer vernetzten Lernumgebung bei asynchron angelegter Diskussion – sowohl online als auch direkt – über einen Universitätskurs. Qualifizierte Ergebnisse zeigen, dass bestimmte Verhaltensmuster der Studenten zur Partizipation vom Persönlichkeitstyp abhängen, insbesondere vom Grad der Introversion/Extroversion, Empfindsamkeit/Einfühlungsvermögen und Denken/Fühlen. Der Beitrag stellt auch Folgerungen aus den Befunden in Bezug auf die Entwicklung vernetzter Lernumgebungen zur Diskussion, um bessere online-Partizipation aller Studenten sicherzustellen.