Purpose: To compare the acute effects of caffeine and placebo ingestion with a control condition (ie, no supplementation) on vertical jump performance. Methods: The sample for this study consisted of 26 recreationally trained men. Following the familiarization visit, the subjects were randomized in a double-blind manner to 3 main conditions: placebo, caffeine, and control. Caffeine was administered in the form of a gelatin capsule in the dose of 6 mg·kg body weight−1. Placebo was also administered in the form of a gelatin capsule containing 6 mg·kg−1 of dextrose. Vertical jump performance was assessed using a countermovement jump performed on a force platform. Analyzed outcomes were vertical jump height and maximal power output. Results: For vertical jump height, significant differences were observed between placebo and control conditions (g = 0.13; 95% confidence interval [CI], 0.03–0.24; +2.5%), caffeine and control conditions (g = 0.31; 95% CI, 0.17–0.50; +6.6%), and caffeine and placebo conditions (g = 0.19; 95% CI, 0.06–0.34; +4.0%). For maximal power output, no significant main effect of condition (P = .638) was found. Conclusions: Ingesting a placebo or caffeine may enhance countermovement jump performance compared with the control condition, with the effects of caffeine versus control appearing to be greater than the effects of placebo versus control. In addition, caffeine was ergogenic for countermovement jump height compared with placebo. Even though caffeine and placebo ingestion improved vertical jump height, no significant effects of condition were found on maximal power output generated during takeoff.
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Jozo Grgic, Sandro Venier and Pavle Mikulic
Kim Gammage, Lori Dithurbide, Alison Ede, Blair Evans, Sean Locke, Eric Martin, Desi McEwan and Kathleen Wilson
Lydia M. Kocher, Jonisha P. Pollard, Ashley E. Whitson and Mahiyar F. Nasarwanji
Footwear plays an important role in worker safety. Work boots with safety toes are often utilized at mine sites to protect workers from hazards. Increasingly, mining operations require metatarsal guards in addition to safety toe protection in boots. While these guards provide additional protection, the impact of metatarsal guards on gait are unknown. This study aimed to measure the effects of 4 safety work boots, steel toe, and steel toe with metatarsal protection in wader- and hiker-style boots, on level and inclined walking gait characteristics, during ascent and descent. A total of 10 participants completed this study. A motion capture system measured kinematics that allowed for the calculation of key gait parameters. Results indicated that gait parameters changed due to incline, similar to previous literature. Wader-style work boots reduced ankle range of motion when ascending an incline. Hip, knee, and ankle ranges of motion were also reduced during descent for this style of boot. Wader-style boots with metatarsal guards led to the smallest ankle range of motion when descending an inclined walkway. From these results, it is likely that boot style affects gait parameters and may impact a miner’s risk for slips, trips, or falls.
Sonja Utz, Felix Otto and Tim Pawlowski
Using social media for crisis communication has been proposed as an effective strategy because it allows teams to build parasocial relationships with fans. The authors focused on the early elimination of Germany during the 2018 Fédération Internationale de Football Association World Cup to examine the effects of (crisis) communication on Facebook. The authors compared the Facebook posts of the German team, captain Manuel Neuer, and team member Thomas Müller and examined the emoji reactions each received. Although Neuer posted text identical to that of the team, his post received a smaller proportion of angry emoji reactions. Müller received fewer angry reactions than the team, but more than Neuer. The authors also used data from a two-wave panel to study changes in evaluation and parasocial relationships and perceived authenticity as potential mediators. Only the team was evaluated more negatively after the elimination than before. Parasocial relationships mediated the effect of exposure to social media posts on evaluation.
Joshua D. Vadeboncoeur, Trevor Bopp and John N. Singer
In this article, the authors drew from the epistemological and methodological considerations of neighboring social science fields (i.e., counseling psychology, education, sociology, and women’s studies), which suggest a reevaluation of reflexive research practice(s). In discussing the implications this reevaluation may have for future sport management research, the authors contend that such dialogue may encourage scholars to understand that, while adopting a reflexive approach is good research practice, it may also mean taking a closer look at how our biases, epistemologies, identities, and values are shaped by whiteness and dominant ways of knowing and, in turn, serve to affect our research practice. Thus, this may allow all researchers, with explicit consideration for those in positions of conceptual, empirical, and methodological, as well as cultural and racial, power, to acknowledge and work toward a more meaningful point of consciousness in conducting sport management research.
Caio Victor Sousa, Beat Knechtle and Pantelis Theo Nikolaidis
Purpose: To analyze the performances of 2 ultra-triathletes who competed in ultra-triathlon events (double Iron ultra-triathlon and triple Iron ultra-triathlon) for the past 3 decades. Longitudinal data of the performance development in ultra-triathlon athletes spanning many years are rare. Prediction of age-related performance declines in the different disciplines in triathlon events (swimming, cycling, and running) are needed for race directors to set realistic goals (time limits) for master athletes in these events. Methods: Athletes A and B had 34 and 53 participations in double Iron at 35–55 and 40–69 y of age, respectively, and 26 and 20 participations in triple Iron at 33–51 and 40–61 y of age, respectively. Nonlinear regression analyses were performed with split and overall performance against age. Results: The average declines in performance in triple Iron ultra-triathlon for athlete A were 0.62%/y, 0.19%/y, and 0.98%/y for swimming, cycling, and running, respectively. For athlete B, a positive change was identified for swimming (0.19%/y) and cycling (1.12%/y) but negative change for running (1.34%/y). Conclusion: Running is the discipline with the greatest performance-decline rate for both athletes, in both double and triple Iron distances. The race time limit of double Iron competitions seems too short, making it difficult for master athletes older than 55 y to finish the race within the event regulations.
Dirk Krombholz, Luca Daniel, Peter Leinen, Thomas Muehlbauer and Stefan Panzer
The main purpose of this study was to determine the covariation of anthropometric parameters and the center of pressure (CoP) of young soccer players. Sub-elite young male players between 16 and 17 years (N = 42) were instructed to perform single-leg balance tasks under different conditions: static and dynamic balance on firm and foam ground. Single-leg balance was measured with a Kistler force plate. The measures of postural control were the CoP displacement in anterior-posterior and medio-lateral directions. Further, the following anthropometric variables were assessed: body height, body weight, foot length, and foot width. Results indicated only two small-sized correlations between body height/weight and the CoP measures. The covariation between body height, body weight, and the CoP measures for the single-leg stance in young male sub-elite soccer players was less than 10%.
Damiano Formenti, Luca Cavaggioni, Marco Duca, Athos Trecroci, Mattia Rapelli, Giampietro Alberti, John Komar and Pierpaolo Iodice
Background: Recent evidence has suggested that chronic physical activities including balance exercises have positive effects on cognition, but their acute effects are still unknown. In the present study, the authors tested the hypothesis that an acute bout of balance exercise would enhance cognitive performance compared with aerobic activity. Methods: A total of 20 healthy middle-aged adults completed 2 acute 30-minute balance and moderate-intensity aerobic exercise sessions on 2 counterbalanced separate occasions. To assess cognitive functions, performance tasks in executive control, perceptual speed, and simple reaction time were tested before and immediately after each exercise session. Results: Although there were no significant interactions (time × exercise condition, P > .05), the main effects of time were significant in executive control (P < .05), perceptual speed (P < .05), and simple reaction time (P < .001), showing improvements after both exercises. Conclusions: These findings highlight that both types of exercise (aerobic, more metabolic and less cognitively demanding; balance, more cognitively and less metabolically demanding) were able to positively affect simple reaction time performance, perceptual speed, and executive control independently of physiological adjustments occurring during aerobic or balance exercise.
Eesha J. Shah, Jia Yi Chow and Marcus J.C. Lee
In adults, longer quiet-eye (QE) durations have been associated with more successful sport performances and less deterioration in skill during anxiety-inducing situations. This study aimed to establish if QE patterns in youth are similar to those reported in adults. Ten youth shooters, age 13.13 ± 0.83 years, completed an air-pistol task under a control and an anxiety condition. Mixed-design 2 (performance outcome) × 2 (condition) ANOVA tests were conducted with two performance measures—objective and coach rated. No significant main or interaction effects were found. Unlike in adults, performance and anxiety did not differentiate QE duration in youth athletes, although QE duration was longer during good shots than poor shots across both performance measures, and the shortest durations were recorded during poor shots in the anxiety condition. This preliminary exploration encourages more research with youth athletes to determine the efficacy of QE patterns across different learners.
Andy J. King, Joshua T. Rowe and Louise M. Burke
The benefits of ingesting exogenous carbohydrate (CHO) during prolonged exercise performance are well established. A recent food technology innovation has seen sodium alginate and pectin included in solutions of multiple transportable CHO, to encapsulate them at pH levels found in the stomach. Marketing claims include enhanced gastric emptying and delivery of CHO to the muscle with less gastrointestinal distress, leading to better sports performance. Emerging literature around such claims was identified by searching electronic databases; inclusion criteria were randomized controlled trials investigating metabolic and/or exercise performance parameters during endurance exercise >1 hr, with CHO hydrogels versus traditional CHO fluids and/or noncaloric hydrogels. Limitations associated with the heterogeneity of exercise protocols and control comparisons are noted. To date, improvements in exercise performance/capacity have not been clearly demonstrated with ingestion of CHO hydrogels above traditional CHO fluids. Studies utilizing isotopic tracers demonstrate similar rates of exogenous CHO oxidation, and subjective ratings of gastrointestinal distress do not appear to be different. Overall, data do not support any metabolic or performance advantages to exogenous CHO delivery in hydrogel form over traditional CHO preparations; although, one study demonstrates a possible glycogen sparing effect. The authors note that the current literature has largely failed to investigate the conditions under which maximal CHO availability is needed; high-performance athletes undertaking prolonged events at high relative and absolute exercise intensities. Although investigations are needed to better target the testimonials provided about CHO hydrogels, current evidence suggests that they are similar in outcome and a benefit to traditional CHO sources.