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.
Andrew J. Higham, James A. Newman, Joseph A. Stone, and James L. Rumbold
Coaches are key socializing agents who influence the sociomoral context. A function of socialization in coaching is the imparting of values and ideology, which guide behavior. English professional football is known for authoritarian and subservient cultures whereby coaches will enforce cultural norms and values, which consequently shape their players’ moral development. Therefore, from a contextual viewpoint, professional football serves as a suitable site for exploring coaches’ views of morality. This study consisted of two aims: (a) explore English professional football coaches’ experiences of morality in football and (b) share coaches’ accounts of how they create and manage a moral atmosphere. Semistructured interviews were conducted with eight male professional English football coaches. Thematic analysis resulted in two general dimensions: coaches’ experiences of morality and recommendations for creating and managing a moral atmosphere. Coaches shared accounts of the moral conflicts and antisocial behaviors they experienced. The findings suggest that coaches struggle to define morality while highlighting the lack of coach education on the topic. Furthermore, similarities were observed in relation to coaches’ recommendations for creating and managing a moral atmosphere. Therefore, the study concludes by providing a selection of guiding principles that professional football coaches could implement when creating and managing a moral atmosphere.
Markus N.C. Williams, Jordan L. Fox, Cody J. O’Grady, Samuel Gardner, Vincent J. Dalbo, and Aaron T. Scanlan
Purpose: To compare weekly training, game, and overall (training and games) demands across phases of the regular season in basketball. Methods: Seven semiprofessional, male basketball players were monitored during all on-court team-based training sessions and games during the regular season. External monitoring variables included PlayerLoad™ and inertial movement analysis events per minute. Internal monitoring variables included a modified summated heart rate zones model calculated per minute and rating of perceived exertion. Linear mixed models were used to compare training, game, and overall demands between 5-week phases (early, middle, and late) of the regular season with significance set at P ≤ .05. Effect sizes were calculated between phases and interpreted as: trivial, <0.20; small, 0.20 to 0.59; moderate, 0.60 to 1.19; large, 1.20 to 1.99; very large, ≥2.00. Results: Greater (P > .05) overall inertial movement analysis events (moderate–very large) and rating of perceived exertion (moderate) were evident in the late phase compared with earlier phases. During training, more accelerations were evident in the middle (P = .01, moderate) and late (P = .05, moderate) phases compared with the early phase, while higher rating of perceived exertion (P = .04, moderate) was evident in the late phase compared with earlier phases. During games, nonsignificant, trivial–small differences in demands were apparent between phases. Conclusions: Training and game demands should be interpreted in isolation and combined given overall player demands increased as the season progressed, predominantly due to modifications in training demands given the stability of game demands. Periodization strategies administered by coaching staff may have enabled players to train at greater intensities late in the season without compromising game intensity.
Gabriel Barreto, Gabriel P. Esteves, Felipe Miguel Marticorena, and Bryan Saunders
Joseph Gandrieau, Christophe Schnitzler, Thibaut Derigny, Clément Lléna, Alexandre Mouton, and François Potdevin
Purpose: Despite its relevance for the training of a well-rounded physically literate individual, the development of knowledge about physical activity (KPA) is understudied. We examined how KPA is differentiated and evolves according to grade level, gender, and type of school attended by an adolescent. Method: A reliable KPA assessment tool was developed. A three-way analysis of variance was used to analyze z scores on the effects of gender, grade level, and type of school on five different dimensions of knowledge. Results: The reliability was validated. Statistically significant interactions were revealed between grade and school institution on KPA z scores. Main results showed that vocational schools displayed significantly lower levels, compared to traditional ones. The only increase in knowledge according to grade was noticeable only in traditional schools. Results revealed no significant gender differences. Discussion: The French physical education system does not seem to provide an adequate level of KPA, especially in vocational schools.
Oliver C. Witard, Laurent Bannock, and Kevin D. Tipton
The acute response of muscle protein synthesis (MPS) to resistance exercise and nutrition is often used to inform recommendations for exercise programming and dietary interventions, particularly protein nutrition, to support and enhance muscle growth with training. Those recommendations are worthwhile only if there is a predictive relationship between the acute response of MPS and subsequent muscle hypertrophy during resistance exercise training. The metabolic basis for muscle hypertrophy is the dynamic balance between the synthesis and degradation of myofibrillar proteins in muscle. There is ample evidence that the process of MPS is much more responsive to exercise and nutrition interventions than muscle protein breakdown. Thus, it is intuitively satisfying to translate the acute changes in MPS to muscle hypertrophy with training over a longer time frame. Our aim is to examine and critically evaluate the strength and nature of this relationship. Moreover, we examine the methodological and physiological factors related to measurement of MPS and changes in muscle hypertrophy that contribute to uncertainty regarding this relationship. Finally, we attempt to offer recommendations for practical and contextually relevant application of the information available from studies of the acute response of MPS to optimize muscle hypertrophy with training.
Anna Thacker, Jennifer Ho, Arsalan Khawaja, and Larry Katz
Purpose: Through video analysis, this paper explores the impact that order of performance has on middle school students’ performance of fundamental movement skills within a peer-to-peer learning model. Order of performance refers to the order in which a student performed a skill while paired up with a peer. Method: Using a mobile application, Move Improve®, 18 students (eight males and 10 females) completed a standing jump and hollow body roll in partners assigned to order of performance (evaluator/performer). An independent samples t test was conducted to evaluate the differences in the mean scores between students who performed first and those who performed second for each skill. Results: There was a significant difference in standing jump scores (p < .01), where students who performed second had a higher average score than their peers who went first. Although not statistically significant (p = .293), results for hollow body roll also showed a similar performance pattern for students who went second compared with those who performed first. Conclusion: The order of performance within a peer-to-peer learning model may have a significant effect on performance scores for standing jump but not for hollow body roll. Reasons for the discrepancy may be due to a combination of skill familiarity, skill complexity, and training of observational learning.