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.
Rhys J. Thurston, Danielle M. Alexander, and Mathieu Michaud
Learning disabilities and neurodevelopmental disorders are the most prevalent disabilities that affect learning. This paper will provide practical recommendations and observations for coaching athletes with three common learning disabilities (dyslexia, dysgraphia, and dyscalculia) and two neurodevelopmental disorders (attention deficit hyperactivity disorder and autism spectrum disorder). Adapted from the literature and in conjunction with previous experiences, the authors provided a range of recommendations for coaches to consider implementing within their practices. The recommendations place an emphasis on the knowledge, strategies, and behaviors of the coach and their role in providing an inclusive, safe, and accessible space for athletes—with or without disabilities—rather than problematizing the disability or the person. Coaches are encouraged to consider their coaching environment (i.e., structure, physical elements, equipment), communication styles (i.e., language, delivery, feedback), and behaviors (e.g., frequent check-ins, review of material). Furthermore, coaches are encouraged to critically reflect on their preconceived biases, assumptions, and experiences with disability and how these play a role in influencing their coaching practices.Considering the prevalence of people with learning disabilities or neurodevelopmental disorders, it is essential for coaches to have access to disability-specific information while remaining cognizant of the needs of the individual when providing an inclusive environment for all.
Ibai Garcia-Tabar, Aitor Iturricastillo, Julen Castellano, Eduardo L. Cadore, Mikel Izquierdo, and Igor Setuain
Purpose: To develop gender-specific operational equations for prediction of cardiorespiratory fitness in female footballers. Method: Forty-eight semiprofessional female footballers performed an intermittent progressive maximal running test for determination of fixed blood lactate concentration (FBLC) thresholds. Relationships between FBLC thresholds and the physiological responses to submaximal running were examined. Developed equations (n = 48) were compared with equations previously obtained in another investigation performed in males (n = 100). Results: Submaximal velocity associated with 90% maximal heart rate was related to FBLC thresholds (r = .76 to .79; P < .001). Predictive power (R 2 = .82 to .94) of a single blood lactate concentration (BLC) sample measured at 10 or 11.5 km·h−1 was very high. A single BLC sample taken after a 5-minute running bout at 8.5 km·h−1 was related to FBLC thresholds (r = −.71; P < .001). No difference (P = .15) in the regression lines predicting FBLC thresholds from velocity associated with 90% maximal heart rate was observed between the female and male cohorts. However, regressions estimating FBLC thresholds by a single BLC sample were different (P = .002). Conclusions: Velocity associated with 90% maximal heart rate was robustly related to FBLC thresholds and might serve for mass field testing independently of sex. BLC equations accurately predicted FBLC thresholds. However, these equations are gender-specific. This is the first study reporting operational equations to estimate the FBLC thresholds in female footballers. The use of these equations reduces the burden associated with cardiorespiratory testing. Further cross-validation studies are warranted to validate the proposed equations and establish them for mass field testing.
Shona L. Halson, Renee N. Appaneal, Marijke Welvaert, Nirav Maniar, and Michael K. Drew
Purpose: Psychological stress is reported to be an important contributor to reduced sleep quality and quantity observed in elite athletes. The purpose of this study was to explore the association between psychological stress and sleep and to identify if specific aspects of sleep are disturbed. Methods: One hundred thirty-one elite athletes (mean [SD], male: n = 46, age 25.8 [4.1] y; female: n = 85, age 24.3 [3.9] y) from a range of sports completed a series of questionnaires in a 1-month period approximately 4 months before the 2016 Rio Olympic Games. Questionnaires included the Pittsburgh Sleep Quality Index; Recovery-Stress Questionnaire; Depression, Anxiety, and Stress Scale (DASS 21); and Perceived Stress Scale (PSS). Results: Regression analysis identified the PSS and DASS stress as the main variables associated with sleep. A PSS score of 6.5 or higher was associated with poor sleep. In addition, a PSS score lower than 6.5 combined with a DASS stress score higher than 4.5 was also associated with poor sleep. Univariate analyses on subcomponents of the Pittsburgh Sleep Quality Index confirmed that PSS is associated with lower sleep quality (t 99 = 2.40, P = .018), increased sleep disturbances (t 99 = 3.37, P = .001), and increased daytime dysfunction (t 99 = 2.93, P = .004). DASS stress was associated with increased sleep latency (t 94 = 2.73, P = .008), increased sleep disturbances (t 94 = 2.25, P = .027), and increased daytime dysfunction (t 94 = 3.58, P = .001). Conclusions: A higher stress state and higher perceived stress were associated with poorer sleep, in particular increased sleep disturbances and increased daytime dysfunction. Data suggest that relatively low levels of psychological stress are associated with poor sleep in elite athletes.
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.