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.
Tiago Duarte, Diane M. Culver, and Kyle Paquette
In this paper, the authors reflect on the current literature and the evolution of coach communities of practice and how the coach development area has embraced Wenger-Trayner’s social learning theory. Studies examining parasport coach development interventions, specifically those using a landscape of practice approach, are lacking. This paper is the third in a series about increasing learning capability in the wheelchair curling landscape. The authors utilized a collaborative approach to assess the learning value created through a 13-month social learning intervention. Four composite vignettes based on the coaches’ pathways and residency within the landscape were created from the data generated and analyzed using the value creation framework. The vignettes illustrate the many dimensions of learning values experienced by the coaches. This paper advances the literature surrounding social learning theory by providing examples of the novel concept of different dimensions of learning value. Applied implications are included.
Naroa Etxebarria, Nicole A. Beard, Maree Gleeson, Alice Wallett, Warren A. McDonald, Kate L. Pumpa, and David B. Pyne
Gastrointestinal disturbances are one of the most common issues for endurance athletes during training and competition in the heat. The relationship between typical dietary intake or nutritional interventions and perturbations in or maintenance of gut integrity is unclear. Twelve well-trained male endurance athletes (peak oxygen consumption = 61.4 ± 7.0 ml·kg−1·min−1) completed two trials in a randomized order in 35 °C (heat) and 21 °C (thermoneutral) conditions and kept a detailed nutritional diary for eight consecutive days between the two trials. The treadmill running trials consisted of 15 min at 60% peak oxygen consumption, 15 min at 75% peak oxygen consumption, followed by 8 × 1-min high-intensity efforts. Venous blood samples were taken at the baseline, at the end of each of the three exercise stages, and 1 hr postexercise to measure gut integrity and the permeability biomarker concentration for intestinal fatty-acid-binding protein, lipopolysaccharide, and lipopolysaccharide-binding protein. The runners self-reported gut symptoms 1 hr postexercise and 3 days postexercise. The heat condition induced large (45–370%) increases in intestinal fatty-acid-binding protein, lipopolysaccharide-binding protein, and lipopolysaccharide concentrations compared with the baseline, but induced mild gastrointestinal symptoms. Carbohydrate and polyunsaturated fat intake 24 hr preexercise were associated with less lipopolysaccharide translocation. Protein, carbohydrate, total fat, and polyunsaturated fat intake (8 days) were positively associated with the percentage increase of intestinal fatty-acid-binding protein in both conditions (range of correlations, 95% confidence interval = .62–.93 [.02, .98]). Typical nutrition intake partly explained increases in biomarkers and the attenuation of symptoms induced by moderate- and high-intensity exercise under both heat and thermoneutral conditions.
Nicole C.A. Strock, Kristen J. Koltun, and Emily A. Ricker
Megan A. Kuikman, Margo Mountjoy, Trent Stellingwerff, and Jamie F. Burr
Collin A. Webster, Jongho Moon, Hayes Bennett, and Stephen Griffin
This study examined the implementation and effectiveness of a comprehensive school physical activity program (CSPAP)-informed, 15-week physical education secondary methods course, adapted from its previous in-person format to be completely online for fall 2020 during the COVID-19 pandemic. The participants were 15 preservice physical education teachers (PPETs) and three course instructors. Each PPET taught six virtual physical education lessons to middle and high school students learning at home. Multiple data sources including focus groups, individual interviews, and course artifacts were analyzed to address research questions centered on the fidelity of course delivery, adaptations made to the course during implementation, and the PPETs’ approach to lesson planning and teaching. The findings showed a high level of implementation fidelity, and few adaptations were made to the course. Three themes were identified with respect to the PPETs’ pedagogical approach: personalization, inquiry-based instruction, and resilience. This study provides a case example of trying to prepare PPETs for professional roles in the COVID era.