It is the position of Sports Dietitians Australia (SDA) that exercise in hot and/or humid environments, or with significant clothing and/or equipment that prevents body heat loss (i.e., exertional heat stress), provides significant challenges to an athlete’s nutritional status, health, and performance. Exertional heat stress, especially when prolonged, can perturb thermoregulatory, cardiovascular, and gastrointestinal systems. Heat acclimation or acclimatization provides beneficial adaptations and should be undertaken where possible. Athletes should aim to begin exercise euhydrated. Furthermore, preexercise hyperhydration may be desirable in some scenarios and can be achieved through acute sodium or glycerol loading protocols. The assessment of fluid balance during exercise, together with gastrointestinal tolerance to fluid intake, and the appropriateness of thirst responses provide valuable information to inform fluid replacement strategies that should be integrated with event fuel requirements. Such strategies should also consider fluid availability and opportunities to drink, to prevent significant under- or overconsumption during exercise. Postexercise beverage choices can be influenced by the required timeframe for return to euhydration and co-ingestion of meals and snacks. Ingested beverage temperature can influence core temperature, with cold/icy beverages of potential use before and during exertional heat stress, while use of menthol can alter thermal sensation. Practical challenges in supporting athletes in teams and traveling for competition require careful planning. Finally, specific athletic population groups have unique nutritional needs in the context of exertional heat stress (i.e., youth, endurance/ultra-endurance athletes, and para-sport athletes), and specific adjustments to nutrition strategies should be made for these population groups.
You are looking at 1 - 10 of 25,139 items for
Alan J. McCubbin, Bethanie A. Allanson, Joanne N. Caldwell Odgers, Michelle M. Cort, Ricardo J.S. Costa, Gregory R. Cox, Siobhan T. Crawshay, Ben Desbrow, Eliza G. Freney, Stephanie K. Gaskell, David Hughes, Chris Irwin, Ollie Jay, Benita J. Lalor, Megan L.R. Ross, Gregory Shaw, Julien D. Périard and Louise M. Burke
E. Earlynn Lauer, Mark Lerman, Rebecca A. Zakrajsek and Larry Lauer
In this paper, we describe the development and content of a mental skills training (MST) program and how a strength and conditioning coach/certified mental coach delivered this program within a United States Tennis Association (USTA) Player Development (PD) program. The purpose of the MST program was to create resilient, confident youth tennis competitors. Specific mental strategies (i.e., journaling, routines, breathing, imagery, self-talk) were identified to best meet the objectives of the MST program and were delivered using a three-pronged approach: (a) classroom lessons, (b) strength and conditioning sessions and on-court lessons, and (c) homework assignments. Specific ways that the USTA PD coaches reinforced the use of these strategies during tennis practice are described. Recommendations for coaches to integrate an MST program in high-performance youth sport environments are also provided.
Patricia Gaion, Michel Milistetd, Fernando Santos, Andressa Contreira, Luciane Arantes and Nayara Caruzzo
Coaching positive youth development (PYD) represents a challenge for many participation and high-performance coaches across the globe, including in Brazil. Coach education has been acknowledged as a formal learning context that may help prepare coaches to effectively foster PYD outcomes and provide high-quality developmental experiences for athletes across different sport contexts. Therefore, the purpose of this paper is to describe the key concepts and existing guidelines for coaching and coach education in Brazil, and provide context-specific recommendations for coach education to include PYD materials. Coaching in Brazil includes a long preparation period that includes diversified opportunities for coach learning. However, there are some discrepancies between the objectives and outcomes prioritized by governing bodies and sport organizations and how learning contexts are framed. In other words, although PYD is considered to be a necessary endeavor, it is not explicitly included in any coach education program. Moving forward, we provide several recommendations, through a bottom-up approach, in order to embed PYD within the Brazilian sport system.
Nicole C.A. Strock, Kristen J. Koltun, Emily A. Southmayd, Nancy I. Williams and Mary Jane De Souza
Energy deficiency in exercising women can lead to physiological consequences. No gold standard exists to accurately estimate energy deficiency, but measured-to-predicted resting metabolic rate (RMR) ratio has been used to categorize women as energy deficient. The purpose of the study was to (a) evaluate the accuracy of RMR prediction methods, (b) determine the relationships with physiological consequences of energy deficiency, and (c) evaluate ratio thresholds in a cross-sectional comparison of ovulatory, amenorrheic, or subclinical menstrual disturbances in exercising women (n = 217). Dual-energy X-ray absorptiometry (DXA) and indirect calorimetry provided data on anthropometrics and energy expenditure. Harris–Benedict, DXA, and Cunningham (1980 and 1991) equations were used to estimate RMR and RMR ratio. Group differences were assessed (analysis of variance and Kruskal–Wallis tests); logistic regression and Spearman correlations related ratios with consequences of energy deficiency (i.e., low total triiodothyronine; TT3). Sensitivity and specificity calculations evaluated ratio thresholds. Amenorrheic women had lower RMR (p < .05), DXA ratio (p < .01), Cunningham1980 (p < .05) and Cunningham1991 (p < .05) ratio, and TT3 (p < .01) compared with the ovulatory group. Each prediction equation overestimated measured RMR (p < .001), but predicted (p < .001) and positively correlated with TT3 (r = .329–.453). A 0.90 ratio threshold yielded highest sensitivity for Cunningham1980 (0.90) and Harris–Benedict (0.87) methods, but a higher ratio threshold was best for DXA (0.94) and Cunningham1991 (0.92) methods to yield a sensitivity of 0.80. In conclusion, each ratio predicted and correlated with TT3, supporting the use of RMR ratio as an alternative assessment of energetic status in exercising women. However, a 0.90 ratio cutoff is not universal across RMR estimation methods.
Pierre Trudel, Michel Milestetd and Diane M. Culver
Facing the increase in the number of publications, often spread across many journals, researchers have developed different approaches to review the literature. In the first part of this article we present the result of an “overview” type of review of literature on sport coach education programs in higher education (HE) between 2000–2018. By sharing the list of the 38 articles found, along with some general characteristics of these, our hope is, as suggested in many reviews of literature, that researchers will use the review to more easily frame their studies and discuss their results. However, there are very few examples of how this is done. We would argue that how researchers use the same review of literature varies depending of their context, research interests, and research paradigm. Therefore, in the second part of the article we highlight what we took from our review of the literature based on our specific research context—Brazilian HE sport coach education programs. The three key topics presented and discussed are: (a) the importance of considering the student-coaches’ biography, (b) how to prepare student-coaches for reflective practice, and (c) the complexity of internships.
Michelle A. Sandrey
Clinical Question: Is there sufficient evidence to determine which low back instability tests should be incorporated into a stabilization classification exam for athletes? Clinical Bottom Line: There is moderate level 2 evidence to include, but not to use in isolation, the prone instability test along with other instability tests in a stabilization classification exam.
Mark Ward, Sarah Gibney, David O’Callaghan and Sinead Shannon
Despite the benefits, one in three older adults in Ireland has low activity levels. This study examined associations between the local social and built environment and physical activity of older adults to identify age-friendly factors that support physical activity among the aging population. Data were from the population-representative Healthy and Positive Ageing Initiative Age-Friendly City and Counties Survey (N = 10,540). Physical activity was measured using a short-form of the International Physical Activity Questionnaire. Mixed-effects negative binomial regression models were adjusted for known health and sociodemographic correlates of physical activity. Results are reported as unstandardized beta coefficients (β) with standard errors. Loneliness, community participation, and difficulty in accessing green spaces partially explained the differences in the number of minutes that respondents were physically active. Combined with individual-level behavior change interventions, improvements to the local environment and promoting social connectedness may also be useful in promoting physical activity among older adults.
Ka Man Leung and Pak-Kwong Chung
This study examined the associations between physical environment, social environment, and walking for transportation and recreation among older adults in Hong Kong. Cross-sectional data from 450 older adults (79 years or younger [71.9%], female [79.7%]) from 18 districts in Hong Kong were used. The participants’ perceptions of their physical and social environments were collected, and their walking behaviors were self-reported. The results revealed that positive physical environment facilitators and social environments were associated with increased total walking. Only positive physical environment facilitators were associated with increased walking for transportation, and physical and social environments had no notable effect on walking for recreation. These findings suggest that policy makers and walking intervention designers should develop strategies to enhance physical and social environments to promote total walking and walking for transportation.
Julia C. Orri, Elizabeth M. Hughes, Deepa G. Mistry and Antone Scala
The authors compared the linear and nonlinear heart rate variability dynamics from rest through maximal exercise in postmenopausal women who trained at either moderate or high intensities. The outcome variables included the RR triangular index, TINN, SD1, SD2, SD1/SD2, DFA α1, DFA α2, and α1/α2. Maximal exercise reduced SD1, SD2, DFA α1, DFA α2, α1/α2, RRTri, and TINN in both groups and increased SD1/SD2 (p < .05). Two minutes of active recovery produced significant increases in SD1, SD2, DFA α1, and TINN, compared with exercise in both groups (p < .0001). There was also a significant main effect between groups for RRTri during exercise recovery, with the moderate group achieving higher levels (p < .04). The authors have shown that both moderate and vigorous exercise training can lead to a healthy response to maximal exercise and recovery, with the moderate group having a slightly improved recovery in the triangular index.
Werner F. Helsen, Nikola Medic, Janet L. Starkes and Andrew M. Williams
Inequalities in relative age distribution have previously been demonstrated to influence participation and performance achievements in Masters athletes. The purpose of the present study was to examine the participation- and performance-related constituent year effect among Masters athletes (N = 2,474) from the European Masters Track and Field Championships across subdisciplines and age. The results indicated that a participation-related constituent year effect was observed. The likelihood of participation was significantly higher for athletes in their first year of any 5-year age category (χ2 = 149.8, p < .001) and decreased significantly when they were in the fourth or fifth year. The results also indicated a performance-related constituent year effect. Masters athletes in their first year won significantly more medals than expected based on observed participation rate (χ2 = 23.39, p < .001). We compare our results with the existing literature and discuss potential mechanisms for this constituent year effect.