This study compared the acute and chronic impact of citrulline malate (CM) supplementation on muscle contractile properties and fatigue rate of the quadriceps. Eighteen recreationally trained males consumed both a placebo (PL) and CM treatment for two separate dosing periods. The first experimental testing session for each dosing period was considered the baseline day, the second session the acute day, and the third session the chronic day, which followed seven consecutive days of supplementation. All testing sessions included exercising on a cycle ergometer at 50%–60% of their max power output for 30 min followed by performing the Thorstensson test on an isokinetic dynamometer. A two-way (Supplement × Time) analysis of variance with repeated measures resulted in no significant interactions (p > .05) (PL: baseline day, acute day, chronic day vs. CM: baseline day, acute day, chronic day) for peak power (in watts) (469 ± 81, 490 ± 97, 502 ± 99 vs. 464 ± 85, 480 ± 103, 501 ± 81); peak torque (in newton meters) (150 ± 26, 157 ± 32, 161 ± 31 vs. 149 ± 27, 156 ± 33, 161 ± 26); fatigue rate (in percentage) (57 ± 9, 57 ± 10, 58 ± 9 vs. 57 ± 10, 56 ± 9, 58 ± 9); and heart rate (in beats per minute) (156 ± 17, 146 ± 13, 146 ± 9 vs. 155 ± 11, 146 ± 11, 146 ± 9). The results of this study suggest that neither acute nor chronic supplementation of CM had an effect on recovery or fatigue rate of the quadriceps.
Alyssa N. Fick, Robert J. Kowalsky, Matthew S. Stone, Christopher M. Hearon, and Tyler M. Farney
Julie McCleery, Jennifer Lee Hoffman, Irina Tereschenko, and Regena Pauketat
Coach development programs have been moving away from knowledge focused, rationalistic pedagogies toward more constructivist, applied approaches that recognize the complex, relational, and contextual nature of coaching and learning to coach. Teacher educators have been doing similar pedagogical work: trying to identify the dynamic elements of what makes an expert teacher and distill those elements into a learner-centered teacher education framework that brings knowledge into action. One such practice-based teacher education framework is ambitious teaching core practices. Core practices are empirically-based moves and social routines that teachers learn to enact adaptively to enhance learning across diverse groups of students. The purpose of this study was to explore the application of ambitious teaching core practices to coach development and take a step toward identifying and defining coaching core practices. Findings from this Delphi panel of expert coaches resulted in 15 ambitious coaching core practices for facilitating athlete performance and well-being including allowing space for athlete exploration, creativity, and problem solving and developing and flexibly executing a practice plan. Applying the concept of core practices to coaching is both a novel way to understand effective coaching and a first step toward a new practice-based coach development framework.
Patrick B. Wilson
Urine specific gravity (USG) thresholds are used in practice and research to determine hypohydration. However, some limited research has found that body size and body composition may impact USG, suggesting that fixed cutoffs may be insensitive. Cross-sectional data from 3,634 participants of the 2007–2008 National Health and Nutrition Examination Survey were analyzed. Along with USG, body mass index (BMI), estimated lean body mass (LBM), and dietary intake were quantified. Logistic regression models were used to evaluate whether higher quintiles of BMI and LBM were associated with elevated USG (USG ≥ 1.020 and ≥1.025) after accounting for dietary moisture and sodium. The USG (1.018 ± 0.0003 vs. 1.015 ± 0.0004); BMI (28.4 ± 0.2 vs. 28.0 ± 0.2 kg/m2); LBM (60.9 ± 0.3 vs. 42.2 ± 0.2 kg); dietary moisture (3,401 ± 92 vs. 2,759 ± 49 g/day); and dietary sodium (4,171 ± 85 vs. 2,959 ± 50) were greater in men than in women (p < .05). Men and women in the fifth quintiles of BMI or LBM (vs. Quintile 1) had greater odds (2.00–3.68, p < .05) of elevated USG. (The only exception was for the association between BMI and USG ≥ 1.025 in men.) Being in Quintile 4 of LBM or BMI (vs. Quintile 1) also tended to be associated with higher odds of elevated of USG, though this pattern was more consistent when using USG ≥ 1.020 than USG ≥ 1.025. In summary, BMI and LBM are associated with USG at the population level. These results affirm that USG depends on body size and composition and raise questions about using fixed USG thresholds for determining hypohydration, particularly for people in the upper quintiles of BMI and LBM.
Ray N. Fredrick III, Risto Marttinen, Kelly Johnston, and Juana Fernandez
Purpose: In the United States, after-school programs have been found to improve healthy behaviors and increase time in safe, structured environments for youth, but less is known about Latin American contexts. The purpose of this study was to examine the implementation of an educational program in an underserved school in Latin America. Method: A qualitative case study was used for this study. A Peace Corps volunteer was the main participant in the study. Data collection included interviews, field notes, artifacts, and reflective notes. Data were coded using constant comparative methods. Results: Three themes emerged that represent program implementation in a Latin American country: (a) learning to teach in a new country with new rules, (b) expectations and going with the flow, and (c) extending the positive youth development model to international outreach programs in rural communities. Conclusion: Relational developmental systems metatheoretical approach to positive youth development through sport model is effective in Latin American settings.
Korey L. Boyd, Mara Simon, and Cory E. Dixon
Introduction: Physical education (PE) and physical education teacher education (PETE) are informed by whiteness, resulting in marginalization and forced hypervisibility for community members of color. Culturally relevant and sustaining pedagogies (CRSP) facilitate “within group . . . [and] across-group cultural practices” for students and teachers of color to thrive. Purpose: This study highlights CRSP grounded in the experiences of Black and Latinx preservice PE teachers enrolled in predominantly White PETE programs. Methods: For this qualitative visual inquiry, 10 Black and Latinx PETE students each completed three interviews, coupled with participant-generated imagery. Data were analyzed inductively and deductively. Results: Students’ narratives included “othering” and hypervisibility. Participants’ understandings of CRSP illustrated the meaning-making they associated with CRSP. Participants identified co-conspirators, sources of support, and PETE pedagogies within a CRSP framework. Conclusion: The narratives support the call to embed CRSP within PETE programs to center students’ diverse cultural and ethnic identities.
Tue A.H. Lassen, Lars Lindstrøm, Simon Lønbro, and Klavs Madsen
The present study investigated individualized sodium bicarbonate (NaHCO3 −) supplementation in elite orienteers and its effects on alkalosis and performance in a simulated sprint orienteering competition. Twenty-one Danish male and female elite orienteers (age = 25.2 ± 3.6 years, height = 176.4 ± 10.9 cm, body mass = 66.6 ± 7.9 kg) were tested twice in order to identify individual time to peak blood bicarbonate (HCO3 − peak) following supplementation of 0.3 g/kg body mass NaHCO3 with and without warm-up. The athletes also performed two 3.5 km time-trial runs (TT-runs) following individualized timing of NaHCO3 supplementation (SBS) or placebo (PLA) on separate days in a randomized, double-blind, cross-over design. The occurrence of individual peak HCO3 − and pH ranged from 60 to 180 min. Mean HCO3 − and pH in SBS were significantly higher compared with PLA 10 min before and following the TT-run (p < .01). SBS improved overall performance in the 3.5 km TT-run by 6 s compared with PLA (775.5 ± 16.2 s vs. 781.4 ± 16.1 s, respectively; p < .05). SBS improved performance in the last half of the TT-run compared with PLA (p < .01). In conclusion, supplementation with NaHCO3 followed by warm-up resulted in individualized alkalosis peaks ranging from 60 to 180 min. Individualized timing of SBS in elite orienteers induced significant alkalosis before and after a 3.5 km TT and improved overall performance time by 6 s, which occurred in the last half of the time trial. The present data show that the anaerobic buffer system is important for performance in these types of endurance events lasting 12–15 min.