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.
Lara Lima Nabuco, Bryan Saunders, Renato André Sousa da Silva, Guilherme Eckhardt Molina, and Caio Eduardo Gonçalves Reis
This study investigated the effects of caffeine mouth rinse on cycling time to exhaustion (TTE) and physiological responses in trained cyclists. In a double-blinded randomized counterbalanced cross-over design, 10 recreationally trained male cyclists (mean ± SD: 32 ± 3 years, 72.8 ± 5.3 kg, 1.78 ± 0.06 m, 13.9% ± 3.3% body fat, peak power output = 289.4 ± 24.7 W) completed two TTE tests cycling at 75% of peak aerobic power following 24 hr of dietary and exercise standardization. Cyclists were administered 25-ml mouth rinses for 5 s containing either 85 mg of caffeine or control (water) every 5 min throughout the exercise tests. No significant improvement in TTE was shown with caffeine mouth rinse compared with control (33:24 ± 12:47 vs. 28:08 ± 10:18 min; Cohen’s dz effect size: 0.51, p = .14). Caffeine mouth rinse had no significant effect on ratings of perceived exertion (p = .31) or heart rate (p = .35) throughout the cycling TTE protocol. These data indicate that a repeated dose of caffeinated mouth rinse for 5 s does not improve cycling TTE in recreationally trained male cyclists. However, these findings should be taken with caution due to the small sample size and blinding ineffectiveness, while further well-design studies with larger samples are warranted.
Tyler Makepeace, Bradley W. Young, and Scott Rathwell
This study explored the views of Canadian Masters athletes (MAs; M age = 51, range 38–62; three men and five women) from 12 sports (10 individual and two team sports) on sport psychology for performance, experiential, and lifestyle enhancement. Using Braun and Clarke’s procedures for thematic analysis, the authors interpreted data from semistructured interviews deductively in relation to five strategic themes in which psychological skills are applied for performance enhancement. Deductive results demonstrated MAs used goal setting, imagery, arousal regulation, concentration, and self-confidence to enhance performance and obtain competitive advantages. The authors also analyzed data inductively to reveal themes related to experiential and lifestyle factors. Inductive results showed that MAs “placed priorities on sport,” which involved cognitively justifying the priority and framing sport as an outlet and as the embodiment of the authentic self. Social strategies associated with continued sport pursuit included cultivation of supportive social environments, social contracts/negotiations, social signaling, and social accountability. Strategies “to fit sport in” included integrating/twinning, scheduling, and managing commitment. Managing age-related concerns involved mindfulness and compensation strategies. Results show how MAs uniquely apply sport psychology to enhance their performance and to support sport adherence.