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Matthias Hovorka, Peter Leo, Dieter Simon, Clemens Rumpl, and Alfred Nimmerichter
Purpose: The purpose of the current investigation was to retrospectively assess possible differences in physiological performance characteristics between junior cyclists signing a contract with an under-23 (U23) development team versus those failing to sign such a contract. Methods: Twenty-five male junior cyclists (age: 18.1 [0.7] y, stature: 181.9 [6.0] cm, body mass: 69.1 [7.9] kg, peak oxygen uptake: 71.3 [6.2] mL·min−1·kg−1) were assigned to this investigation. Between September and October of the last year in the junior category, each cyclist performed a ramp incremental exercise test to determine certain physiological performance characteristics. Subsequently, participants were divided in 2 groups: (1) those signing a contract with a U23 development team (JUNIORU23) and (2) those failing to sign such a contract (JUNIORNON-U23). Unpaired t tests were used to assess possible between-groups differences in physiological performance characteristics. The level of statistical significance was set at P < .05 two tailed. Results: No significant between-groups differences in submaximal (ie, gas exchange threshold, respiratory compensation point) and maximal physiological performance characteristics (ie, peak work rate, peak oxygen uptake) expressed in absolute values (ie, L·min−1, W) were observed (P > .05). However, significant between-groups differences were observed when physiological performance characteristics were expressed relative to the cyclists’ body weights (P < .05). Conclusions: The current investigation showed that junior cyclists stepping up to a U23 development team might be retrospectively differentiated from junior cyclists not stepping up based on certain physiological performance characteristics, which might inform practitioners and/or federations working with young cyclists during the long-term athletic development process.
Timothy D. Griest, Michael J. Saunders, Christopher J. Womack, and Nicholas D. Luden
Purpose: The primary objective was to assess the performance benefits of caffeine (CAF) supplementation in habitual users. Importantly, this investigation was designed to account for the potential confounding effects of CAF withdrawal (CAFW), which are inherent and common in previous work. Methods: Ten CAF-consuming (394 [146] mg·d−1) recreational cyclists (age 39.1 [14.9] y; maximum oxygen consumption 54.2 [6.2] mL·kg–1·min–1) completed four 10-km time trials (TTs) on a cycle ergometer. On each trial day, 8 hours before reporting to the laboratory, subjects consumed 1.5 mg·kg–1 CAF to prevent withdrawal (no withdrawal [N]) or a placebo (PLA; withdrawal [W]). Then, 1 hour prior to exercise, they received either 6 mg·kg–1 CAF or PLA. These protocols were repeated 4 times, employing all combinations of N/W and CAF/PLA. Results: CAFW did not impair TT power output (PLAW vs PLAN P = .13). However, preexercise CAF only improved TT performance when compared to PLA in the W condition (CAFN vs PLAW P = .008, CAFW vs PLAW P = .04), not when W was mitigated (PLAN vs CAFN P = .33). Conclusions: These data indicate that preexercise CAF only improves recreational cycling performance when compared to bouts preceded by CAF abstinence, suggesting that habitual users may not benefit from 6 mg·kg–1 of CAF and that previous work may have overstated the value of CAF supplementation for habitual users. Future work should examine higher doses of CAF for habitual users.
Ricardo J.S. Costa, Kayla Henningsen, Stephanie K. Gaskell, Rebekah Alcock, Alice Mika, Christopher Rauch, Samuel N. Cheuvront, Phil Blazy, and Robert Kenefick
The study aimed to determine the effects of two differing amino acid beverage interventions on biomarkers of intestinal epithelial integrity and systemic inflammation in response to an exertional-heat stress challenge. One week after the initial assessment, participants (n = 20) were randomly allocated to complete two exertional-heat stress trials, with at least 1 week washout. Trials included a water control trial (CON), and one of two possible amino acid beverage intervention trials (VS001 or VS006). On VS001 (4.5 g/L) and VS006 (6.4 g/L), participants were asked to consume two 237-ml prefabricated doses daily for 7 days before the exertional-heat stress, and one 237-ml dose immediately before, and every 20 min during 2-hr running at 60% maximal oxygen uptake in 35 °C ambient conditions. A water volume equivalent was provided on CON. Whole blood samples were collected pre-, immediately post-, 1 and 2 hr postexercise, and analyzed for plasma concentrations of cortisol, intestinal fatty acid protein, soluble CD14, and immunoglobulin M (IgM) by ELISA, and systemic inflammatory cytokines by multiplex. Preexercise resting biomarker concentrations for all variables did not significantly differ between trials (p > .05). A lower response magnitude for intestinal fatty acid protein (mean [95% CI]: 249 [60, 437] pg/ml, 900 [464, 1,336] pg/ml), soluble CD14 (−93 [−458, 272] ng/ml, 12 [−174, 197] ng/ml), and IgM (−6.5 [−23.0, 9.9] MMU/ml, −10.4 [−16.2, 4.7] MMU/ml) were observed on VS001 and V006 compared with CON (p < .05), respectively. Systemic inflammatory response profile was lower on VS001, but not VS006, versus CON (p < .05). Total gastrointestinal symptoms did not significantly differ between trials. Amino acid beverages’ consumption (i.e., 4.5–6.4 g/L), twice daily for 7 days, immediately before, and during exertional-heat stress ameliorated intestinal epithelial integrity and systemic inflammatory perturbations associated with exercising in the heat, but without exacerbating gastrointestinal symptoms.
Manoel Rios, Rodrigo Zacca, Rui Azevedo, Pedro Fonseca, David B. Pyne, Victor Machado Reis, Daniel Moreira-Gonçalves, and Ricardo J. Fernandes
Aim: To quantify the physiological demands and impact of muscle function t of the Fran workout, one of the most popular CrossFit benchmarks. Methods: Twenty experienced CrossFitters—16 male: 29 (6) years old and 4 female: 26 (5) years old— performed 3 rounds (with 30-s rests in between) of 21–21, 15–15, and 9–9 front squats to overhead press plus pull-up repetitions. Oxygen uptake and heart rate were measured at baseline, during the workout, and in the recovery period. Rating of perceived exertion, blood lactate, and glucose concentrations were assessed at rest, during the intervals, and in the recovery period. Muscular fatigue was also monitored at rest and at 5 minutes, 30 minutes, and 24 hours postexercise. Repeated-measures analysis of variance was performed to compare time points. Results: Aerobic (52%–29%) and anaerobic alactic (30%–23%) energy contributions decreased and the anaerobic lactic contribution increased (18%–48%) across the 3 rounds of the Fran workout. Countermovement jump height decreased by 8% (−12 to −3) mean change (95% CI), flight duration by 14% (−19 to −7), maximum velocity by 3% (−5 to −0.1), peak force 4% (−7 to −0.1), and physical performance (plank prone 47% [−54 to −38]) were observed. Conclusions: It appears that the Fran workout is a physically demanding activity that recruits energy from both aerobic and anaerobic systems. This severe-intensity workout evokes substantial postexercise fatigue and corresponding reduction in muscle function.
Colleen X. Muñoz and Michael F. Bergeron
First morning urine (FMU) assessment would be a practical and convenient solution for clinically acceptable detection of underhydration prior to competition/training, and for the general public. Thus, we thus sought to determine the diagnostic accuracy of FMU as a valid indicator of recent (previous 24 hr, 5 days average) hydration practices. For 5 consecutive days and one final morning, 67 healthy women (n = 38) and men (n = 29; age: 20 [1] years, body mass index: 25.9 [5.5]) completed 24-hr diet logs for total water intake (from beverages and foods, absolute and relative to body mass), 24-hr urine and FMU collection (last morning only) for osmolality (Osm), specific gravity (SG), and color (Col), and morning blood sampling for plasma osmolality and copeptin. Correlations determined significance and relationship strength among FMU and all other variables. Area under the receiver operating characteristic curves, sensitivity, specificity, and positive likelihood ratios were employed using previously reported values to indicate underhydration (total water intake < 30 ml/kg, osmolality > 500, and >800 mOsm/kg, specific gravity > 1.017, and copeptin > 6.93 pmol/L). FMU_Osm and FMU_SG were significantly correlated (p < .05) to all variables except the previous 5-day plasma osmolality. FMU_Col was only significantly correlated with other color time intervals and total water intake per gram. FMU_Osm held greatest utility (area under the receiver operating characteristic curve, sensitivity, and specificity >80%) overall, with the best outcome being FMU_Osm indicating a previous 24-hr osmolality threshold of 500 mOsm/kg (FMU_Osm criterion >710 mOsm/kg and positive likelihood ratio = 5.9). With less effort and cost restriction, FMU is a viable metric to assess underhydration.
Sarah R. Jackman, Gareth A. Wallis, Jinglei Yu, Andrew Philp, Keith Baar, Kevin D. Tipton, and Oliver C. Witard
Branched-chain amino acids (BCAA) and carbohydrate (CHO) are commonly recommended postexercise supplements. However, no study has examined the interaction of CHO and BCAA ingestion on myofibrillar protein synthesis (MyoPS) rates following exercise. We aimed to determine the response of MyoPS to the co-ingestion of BCAA and CHO following an acute bout of resistance exercise. Ten resistance-trained young men completed two trials in counterbalanced order, ingesting isocaloric drinks containing either 30.6-g CHO plus 5.6-g BCAA (B + C) or 34.7-g CHO alone following a bout of unilateral, leg resistance exercise. MyoPS was measured postexercise with a primed, constant infusion of L-[ring13C6] phenylalanine and collection of muscle biopsies pre- and 4 hr postdrink ingestion. Blood samples were collected at time points before and after drink ingestion. Serum insulin concentrations increased to a similar extent in both trials (p > .05), peaking at 30 min postdrink ingestion. Plasma leucine (514 ± 34 nmol/L), isoleucine (282 ± 23 nmol/L), and valine (687 ± 33 nmol/L) concentrations peaked at 0.5 hr postdrink in B + C and remained elevated for 3 hr during exercise recovery. MyoPS was ∼15% greater (95% confidence interval [−0.002, 0.028], p = .039, Cohen’s d = 0.63) in B + C (0.128%/hr ± 0.011%/hr) than CHO alone (0.115%/hr ± 0.011%/hr) over the 4 hr postexercise period. Co-ingestion of BCAA and CHO augments the acute response of MyoPS to resistance exercise in trained young males.
Edward B. Olsen, Emi Tsuda, James D. Wyant, Ranaysia Burrell, Jessica Mukherjee, Ara McKay, Joseph Herrera, and David Labrador
Purpose: There are limited school physical activity policy dissemination and implementation studies. This is a concern given the adverse mental, physical, and socio-emotional effects the COVID-19 pandemic has had on children and adolescents. This study explored New Jersey school administrators’ experiences in disseminating recess guidelines, procedures, and policies as well as implementation strategies in their schools during the pandemic. Methods: A total of 29 elementary school administrators participated in semi-structured interviews. The data were analyzed inductively using a conventional approach to qualitative content analysis. Results: In analyzing the data, five themes were identified: (a) adjustments for recess, (b) communications about recess, (c) successes and challenges of recess, (d) health and well-being among children, and (e) recommendations for recess postpandemic. Discussion/Conclusion: When planning, organizing, and implementing a recess in a postpandemic era, school leaders may want to consider establishing cohorts, developing a handbook, creating a rotation schedule (i.e., blacktop, field, playground), developing a recess committee, utilizing the physical education teacher for staff development, assigning recess equipment and bags, offering a variety of activities, and teaching children how to play.
Chad M. Killian, Risto Marttinen, Donal Howley, Julia Sargent, and Emily M. Jones
This research note suggests the emergence of Artificial Intelligence-powered chatbots like ChatGPT pose challenges to the future of higher education. We as a field should pay attention to issues and opportunities associated with this technology across learning, teaching, and research spaces. We propose ignoring, or being indifferent to, predictions about what technologies like Artificial Intelligence-powered chatbots can do can cause us to do “dumb things.” All health and physical education teacher education faculty members should make efforts to learn about these tools to facilitate informed, solution-focused decisions about whether and where to leverage them. We highlight the importance of maintaining sociocritical perspectives when considering use of digital technologies to understand and address digital (in)equity and promote equitable practices. We conclude by emphasizing the need for field-specific consensus statements to guide ethical and appropriate use of Artificial Intelligence-powered chatbots, to ensure the value of these tools is harnessed for the good of the society. [Output by ChatGPT-3]
Zack E. Beddoes and Debra S. Sazama
Purpose: To investigate school principals’ perceptions and applications of professional learning communities (PLCs) and how they interpret the roles of physical educators within these structures. Method: This study was conceptualized as an exploratory interview study. Eight elementary and two secondary school principals across four districts participated in semistructured interviews. Each principal had been trained and was currently utilizing the same PLC framework within their respective schools. Result: Data analysis revealed three overarching themes with supportive subthemes: (a) PLCs are Centered on and Structured for Student Learning, (b) The Roles of Physical Educators Differ in Perception and Function, and (c) Successful PLCs are Facilitated by Team Trust and Disrupted by Drift. Discussion: The findings carry implications for principals, physical educators, and physical education teacher education programs. Principals and physical educators have mutually reinforcing responsibilities in creating an equitable space for physical education in the school PLC community.
