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.
ZáNean McClain, Erin Snapp, Daniel W. Tindall, and Jill Anderson
Mark Partington, Jimmy O’Gorman, Kenny Greenough, and Ed Cope
Little is known about the development of coach developers despite their importance in supporting coach learning. In response, this study explored the theories in practice of 23 English coach developers who undertook a continuing professional development course. The data were collected through semistructured interviews, focus groups, and observations of coach developers’ practice and engagement on the course. The data were analysed using a phronetic-iterative approach, with Argyris and Schön’s ideas on theories in practice, mostly espoused theories and theories-in-use, providing the primary heuristic framework. The findings identified how, before the continuing professional development course, the coach developers articulated espoused theories, but as the course progressed, there was a move to theories-in-use. This was due to their (re)constructed understanding of learning and the working environment. The findings are discussed in light of how the continuing professional development course, and tutors’ pedagogic approaches, influenced the coach developers’ knowledge and understanding. Based on these findings, it seems there is much to gain from supporting coach developers with a deconstruction and reconstruction of theories in practice.
Stephanie Beni, Tim Fletcher, and Déirdre Ní Chróinín
Purpose: The purposes of this research were to design a professional development (PD) initiative to introduce teachers to a pedagogical innovation—the Meaningful Physical Education (PE) approach—and to understand their experiences of the PD process. Method: Twelve PE teachers in Canada engaged in an ongoing PD initiative, designed around characteristics of effective PD, across two school years as they learned about and implemented Meaningful PE. Qualitative data were collected and analyzed. Findings: This research showed that teachers valued a community of practice and modeling when learning to implement Meaningful PE. While teachers were mostly favorable to the PD design, there were several tensions between ideal and realistic forms of PD. Discussion: This research offers support for several characteristics of effective PD to support teachers’ implementation of a novel pedagogical approach and highlights the need to balance tensions in providing forms of PD that are both effective and practical.
Matthew Andrew, Paul R. Ford, Matthew T. Miller, Allistair P. McRobert, Nathan C. Foster, Guido Seerden, Martin Littlewood, and Spencer J. Hayes
We examined whether practice activities adopted by professional youth soccer coaches are modulated through the implementation of and engagement with cocreative evidence-based programs. Across two experiments, we used systematic observation to identify the practice activities of seven coaches across 134 sessions. In Experiment A, drill-based and games-based activities were recorded and quantified. To encourage behaviour change across the study, the systematic observation data were compared with skill acquisition literature to provide coaches with quantitative feedback and recommendations during workshops. Postworkshop systematic observation data indicated that practice activities used by coaches changed in accordance with the evidenced-based information (increase in games-based activities) delivered within the workshop. Interview data indicated that coaches typically stated that the workshop was a key reason for behaviour change. In a follow-up Experiment B, feedback and recommendations were delivered using an interactive video-based workshop. The systematic observation data indicated that coaches increased the use of soccer activities that contained active decision making with coaches citing the workshop as a key reason for behaviour change. These findings indicate that coaching practice activities can be supported and shaped through the implementation of cocreated workshops wherein coaches collaborate with sport scientists and researchers to bridge the gap between science and application.
Michael H. Haischer, John Krzyszkowski, Stuart Roche, and Kristof Kipp
Maximal strength is important for the performance of dynamic athletic activities, such as countermovement jumps (CMJ). Although measures of maximal strength appear related to discrete CMJ variables, such as peak ground reaction forces (GRF) and center-of-mass (COM) velocity, knowledge about the association between strength and the time series patterns during CMJ will help characterize changes that can be expected in dynamic movement with changes in maximal strength. Purpose: To investigate the associations between maximal strength and GRF and COM velocity patterns during CMJ. Methods: Nineteen female college lacrosse players performed 3 maximal-effort CMJs and isometric midthigh pull. GRF and COM velocity time series data from the CMJ were time normalized and used as inputs to principal-components analyses. Associations between isometric midthigh pull peak force and CMJ principal-component scores were investigated with a correlational analysis. Results: Isometric midthigh pull peak force was associated with several GRF and COM velocity patterns. Correlations indicated that stronger players exhibited a GRF pattern characterized by greater eccentric-phase rate of force development, greater peak GRF, and a unimodal GRF profile (P = .016). Furthermore, stronger athletes exhibited a COM velocity pattern characterized by higher velocities during the concentric phase (P = .004). Conclusions: Maximal strength is correlated to specific GRF and COM velocity patterns during CMJ in female college lacrosse athletes. Since maximal strength was not correlated with discrete CMJ variables, the patterns extracted via principal-components analyses may provide information that is more beneficial for performance coaches and researchers.