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.
Lambros Stefanou, Niki Tsangaridou, Charalambos Y. Charalambous, and Leonidas Kyriakides
Purpose: Teacher content knowledge (CK) and its contribution to student achievement (SA) are understudied in physical education, especially concerning the examination of the effectiveness of professional development (PD) programs using direct measures of teachers’ CK and SA. To make progress in this research area, this study investigated the contribution of a content-focused PD program to teachers’ CK and SA in basketball, using direct measures thereof. Methods: A quasi-experimental design was utilized to examine the contribution of a PD program. The authors measured the CK of 52 elementary classroom teachers and their fifth or sixth grade students’ (n = 913) achievement in basketball before and after the PD program. The data were analyzed using unilevel and multilevel regression analyses. Results: Teachers who participated in the PD program exhibited higher learning gains in their CK; their students also exhibited higher learning gains. Discussion and Conclusion: The study findings suggest that PD programs focused on enhancing teachers’ CK might also support SA.
Insook Kim and Phillip Ward
Purpose: This study examined the effects of a specialized content knowledge workshop on developing teachers’ content development and adaptive competence in teaching badminton. Method: A quasi-experimental design was employed with three middle school physical education teachers who taught five or six badminton lessons before and after the content knowledge workshop (n = 66). Descriptive statistics and univariate analysis of variance were conducted to analyze the data of content development index scores and intratask adaptations. Frequency data across lessons by teachers and treatment conditions were employed for content development patterns. Results: There were statistically significant effects of the workshop in developing the teachers’ use of content development (p = .049) and adaptations (p = .000), but their effects varied by teacher. While the most used content development pattern by the teachers in comparison classes was an informing applying pattern, the teachers used a variety of content development patterns that included more task progressions in the experimental classes. Conclusion: It can be concluded that teachers’ instructional tasks and task adaptations could be improved through a well-designed professional development program. The findings can guide the direction of teacher education and professional development in ways to enhance teachers’ content development and adaptations.
Okseon Lee, Euichang Choi, Victoria Goodyear, Mark Griffiths, Hyukjun Son, Hyunsoo Jung, and Wonhee Lee
Although physical education (PE) teachers have increased access to digital/online continuous professional development activities, there are few robust accounts of how they engage with and experience these environments. Purpose: The purpose of this study was to examine PE teachers’ participation patterns within self-directed online PE continuous professional development activities using mobile instant messenger. Methods: Data were generated from (a) 5,246 messages exchanged in the mobile instant messenger chatroom from 281 teachers, (b) semistructured interviews with 10 teachers, and (c) 1,275 messages posted by the 10 interviewed teachers. Quantitative data were analyzed for measures of central tendency, and qualitative data were analyzed inductively. Findings: Five patterns of PE teachers’ usage of mobile instant messenger were identified: (a) ringmasters, (b) passive uploaders, (c) active uploaders, (d) requesters, and (e) bystanders. Discussion: The findings suggest that each engagement pattern illustrates the differential goals of learning, types of interaction, and forms of participation by teachers engaged in online continuous professional development.
Jonne A. Kapteijns, Kevin Caen, Maarten Lievens, Jan G. Bourgois, and Jan Boone
Purpose: To determine if there is a link between the demands of competitive game activity and performance profiles of elite female field hockey players. Methods: Global positioning systems (GPS) were used to quantify running performance of elite female field hockey players (N = 20) during 26 competitive games. Performance profiles were assessed at 2 time points (preseason and midseason) for 2 competitive seasons. A battery of anthropometric and performance field-based tests (30–15 intermittent fitness test, incremental run test, 10–30-m speed test, T test, and vertical jump test) were used to determine the performance profiles of the players. Results: Players covered a mean total distance of 5384 (835) m, of which 19% was spent at high intensities (zone 5: 796  m; zone 6: 274  m). Forwards covered the lowest mean total distance (estimated marginal means 4586 m; 95% confidence interval, 4275–4897), whereas work rate was higher in forwards compared with midfielders (P = .006, d = 0.43) and central defenders (P = .001, d = 1.41). Players showed an improvement in body composition and anaerobic performance from preseason to midseason. Aerobic performance capacity (maximal oxygen uptake and speed at the 4-mM lactate threshold) was positively correlated with high-intensity activities. Conclusions: There is a clear relationship between running performance and aerobic performance profiles in elite female hockey players. These results highlight the importance of a well-developed aerobic performance capacity in order to maintain a high performance level during hockey games.
K. Andrew R. Richards, Karen Lux Gaudreault, and Wesley J. Wilson
The purpose of this research note is to introduce and overview both the teaching and research applications of autobiographical essay writing. Grounded in occupational socialization theory and teacher reflection, the authors propose that autobiography can be a powerful tool in helping preservice and in-service teachers more deeply reflect on their prior socialization experiences, which may help them to better understand and be willing to critique their personal belief structures. The authors provide an overview of how autobiographical essays have been used and include recommendations for teacher education practice. From a research perspective, the authors argue that autobiographical essays provide a targeted strategy for collecting reflective data on individuals’ background socialization experiences. Such data are critical for socialization scholars who are interested in understanding how teachers’ biographies influence their current teaching beliefs and practices. Applications for physical education-adjacent spaces, including doctoral education, adapted physical education, and elementary education, are also discussed.
Alejandro Pérez-Castilla, Daniel Boullosa, and Amador García-Ramos
Objective: To evaluate the sensitivity of the iLOAD® application to detect the changes in mean barbell velocity of complete sets following power- and strength-oriented resistance training (RT) programs. Methods: Twenty men were randomly assigned to a power training group (countermovement jump and bench press throw at 40% of the 1-repetition maximum [1RM]) or strength training group (back squat and bench press at 70% to 90% of 1RM). Single sets of 10 repetitions at 25% and 70% of 1RM during the back squat and bench press exercises were assessed before and after the 4-week RT programs simultaneously with the iLOAD® application and a linear velocity transducer. Results: The power training group showed a greater increment in velocity performance at the 25% of 1RM (effect size range = 0.66–1.53) and the 70% of 1RM (effect size range = 0.11–0.30). The percent change in mean velocity after the RT programs highly correlated between the iLOAD® application and the linear velocity transducer for the back squat (r range = .85–.88) and bench press (r range = .87–.93). However, the iLOAD® application revealed a 2% greater increase in mean velocity after training compared to the linear velocity transducer. Conclusions: The iLOAD® application is a cost-effective, portable, and easy-to-use tool which can be used to detect changes in mean barbell velocity after power- and strength-oriented RT programs.