Alannah K.A. McKay, Peter Peeling, David B. Pyne, Nicolin Tee, Marijke Welveart, Ida A. Heikura, Avish P. Sharma, Jamie Whitfield, Megan L. Ross, Rachel P.L. van Swelm, Coby M. Laarakkers, and Louise M. Burke
This study implemented a 2-week high carbohydrate (CHO) diet intended to maximize CHO oxidation rates and examined the iron-regulatory response to a 26-km race walking effort. Twenty international-level, male race walkers were assigned to either a novel high CHO diet (MAX = 10 g/kg body mass CHO daily) inclusive of gut-training strategies, or a moderate CHO control diet (CON = 6 g/kg body mass CHO daily) for a 2-week training period. The athletes completed a 26-km race walking test protocol before and after the dietary intervention. Venous blood samples were collected pre-, post-, and 3 hr postexercise and measured for serum ferritin, interleukin-6, and hepcidin-25 concentrations. Similar decreases in serum ferritin (17–23%) occurred postintervention in MAX and CON. At the baseline, CON had a greater postexercise increase in interleukin-6 levels after 26 km of walking (20.1-fold, 95% CI [9.2, 35.7]) compared with MAX (10.2-fold, 95% CI [3.7, 18.7]). A similar finding was evident for hepcidin levels 3 hr postexercise (CON = 10.8-fold, 95% CI [4.8, 21.2]; MAX = 8.8-fold, 95% CI [3.9, 16.4]). Postintervention, there were no substantial differences in the interleukin-6 response (CON = 13.6-fold, 95% CI [9.2, 20.5]; MAX = 11.2-fold, 95% CI [6.5, 21.3]) or hepcidin levels (CON = 7.1-fold, 95% CI [2.1, 15.4]; MAX = 6.3-fold, 95% CI [1.8, 14.6]) between the dietary groups. Higher resting serum ferritin (p = .004) and hotter trial ambient temperatures (p = .014) were associated with greater hepcidin levels 3 hr postexercise. Very high CHO diets employed by endurance athletes to increase CHO oxidation have little impact on iron regulation in elite athletes. It appears that variations in serum ferritin concentration and ambient temperature, rather than dietary CHO, are associated with increased hepcidin concentrations 3 hr postexercise.
Heitor O. Santos, Gederson K. Gomes, Brad J. Schoenfeld, and Erick P. de Oliveira
Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g., microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.
Julie McCleery, Jennifer Lee Hoffman, Irina Tereschenko, and Regena Pauketat
Coach development programs have been moving away from knowledge focused, rationalistic pedagogies toward more constructivist, applied approaches that recognize the complex, relational, and contextual nature of coaching and learning to coach. Teacher educators have been doing similar pedagogical work: trying to identify the dynamic elements of what makes an expert teacher and distill those elements into a learner-centered teacher education framework that brings knowledge into action. One such practice-based teacher education framework is ambitious teaching core practices. Core practices are empirically-based moves and social routines that teachers learn to enact adaptively to enhance learning across diverse groups of students. The purpose of this study was to explore the application of ambitious teaching core practices to coach development and take a step toward identifying and defining coaching core practices. Findings from this Delphi panel of expert coaches resulted in 15 ambitious coaching core practices for facilitating athlete performance and well-being including allowing space for athlete exploration, creativity, and problem solving and developing and flexibly executing a practice plan. Applying the concept of core practices to coaching is both a novel way to understand effective coaching and a first step toward a new practice-based coach development framework.
Katie Slattery, Stephen Crowcroft, and Aaron J. Coutts
Scott McLean, Hugo A. Kerhervé, Nicholas Stevens, and Paul M. Salmon
Purpose: The broad aim of sport-science research is to enhance the performance of coaches and athletes. Despite decades of such research, it is well documented that sport-science research lacks empirical evidence, and critics have questioned its scientific methods. Moreover, many have pointed to a research–practice gap, whereby the work undertaken by researchers is not readily applied by practitioners. The aim of this study was to use a systems thinking analysis method, causal loop diagrams, to understand the systemic issues that interact to influence the quality of sport-science research. Methods: A group model-building process was utilized to develop the causal loop diagram based on data obtained from relevant peer-reviewed literature and subject-matter experts. Results: The findings demonstrate the panoply of systemic influences associated with sport-science research, including the existence of silos, a focus on quantitative research, archaic practices, and an academic system that is incongruous with what it actually purports to achieve. Conclusions: The emergent outcome of the interacting components is the creation of an underperforming sport-science research system, as indicated by a lack of ecological validity, translation to practice, and, ultimately, a research–practice gap.
Abraham García-Fariña, Francisco Jiménez Jiménez, and M. Teresa Anguera
Purpose: This study aims to identify socioconstructivist communication patterns used by physical education teachers and their evolution after participating in a training intervention. Method: The authors analyzed 812 units (messages containing constructivist discursive strategies) employed by two physical education teachers in two teaching modules using observational methodology. The data were analyzed by polar coordinate analysis. Results: In the pretraining phase, Teacher 1 presents two discursive patterns with questions–answers–literal incorporation of student-answers into the teachers’ communication, and another formed by praise questions. Teacher 2 generated praise-questions only. In the posttraining phase, Teacher 1 maintains one of the initial patterns and generates another consisting of questions-incorporation of students’ actions into the teacher’s communication. Teacher 2 incorporates two new patterns composed of information demands that are associated with the use of a specific frame of reference, or meta-statement. Discussion: The use of polar coordinate analysis revealed the presence of communication patterns and their evolution. Conclusion: The training intervention has resulted in changes in the communicative patterns of teachers. The custom-made instrument has allowed knowing the discursive strategies
Julian North, Bettina Callary, Kristen Dieffenbach, Larissa Galatti, Sergio Lara-Bercial, Christine Nash, and Donna O’Connor
This article provides an overview of the context, details, and outcomes of a consultation and review of the International Council for Coaching Excellence’s interactions and engagements with, and service provision to, the international sport coaching research community. The consultation and review were undertaken by the International Council for Coaching Excellence Research Committee (RC). The paper starts with a description of the sport coaching research landscape. It then provides details of the role of the International Council for Coaching Excellence, its Research Fair, and RC. The paper then offers an overview of the formal initiation of the consultation and review at the Global Coach Conference, Japan 2019, as well as a brief overview of the approach used. It then details the consultation findings providing direction for the RC moving forward. The resultant revised RC terms of reference are included as an appendix.