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Bethany Wisthoff, Shannon Matheny, Aaron Struminger, Geoffrey Gustavsen, Joseph Glutting, Charles Swanik and Thomas W. Kaminski

Context: Lateral ankle sprains commonly occur in an athletic population and can lead to chronic ankle instability. Objective: To compare ankle strength measurements in athletes who have mechanical laxity and report functional instability after a history of unilateral ankle sprains. Design: Retrospective cohort. Setting: Athletic Training Research Lab. Participants: A total of 165 National Collegiate Athletic Association Division I athletes, 97 males and 68 females, with history of unilateral ankle sprains participated. Main Outcome Measures: Functional ankle instability was determined by Cumberland Ankle Instability Tool scores and mechanical ankle instability by the participant having both anterior and inversion/eversion laxity. Peak torque strength measures, concentric and eccentric, in 2 velocities were measured. Results: Of the 165 participants, 24 subjects had both anterior and inversion/eversion laxity and 74 self-reported functional ankle instability on their injured ankle. The mechanical ankle instability group presented with significantly lower plantar flexion concentric strength at 30°/s (139.7 [43.7] N·m) (P = .01) and eversion concentric strength at 120°/s (14.8 [5.3] N·m) (P = .03) than the contralateral, uninjured ankle (166.3 [56.8] N·m, 17.4 [6.2] N·m, respectively). Conclusion: College athletes who present with mechanical laxity on a previously injured ankle exhibit plantar flexion and eversion strength deficits between ankles.

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Lauren E. Brown

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Tiago Turnes, Rafael Penteado dos Santos, Rafael Alves de Aguiar, Thiago Loch, Leonardo Trevisol Possamai and Fabrizio Caputo

Purpose: To compare the intensity and physiological responses of deoxygenated hemoglobin breaking point ([HHb]BP) and anaerobic threshold (AnT) during an incremental test and to verify their association with 2000-m rowing-ergometer performance in well-trained rowers. Methods: A total of 13 male rowers (mean [SD] age = 24 [11] y and V˙O2peak = 63.7 [6.1] mL·kg−1·min−1) performed a step incremental test. Gas exchange, vastus lateralis [HHb], and blood lactate concentration were measured. Power output, V˙O2, and heart rate of [HHb]BP and AnT were determined and compared with each other. A 2000-m test was performed in another visit. Results: No differences were found between [HHb]BP and AnT in the power output (236 [31] vs 234 [31] W; Δ = 0.7%), 95% confidence interval [CI] 6.7%), V˙O2 (4.2 [0.5] vs 4.3 [0.4] L·min−1; Δ = −0.8%, 95% CI 4.0%), or heart rate (180 [16] vs 182 [12] beats·min−1; Δ = −1.6%, 95% CI 2.1%); however, there was high typical error of estimate (TEE) and wide 95% limits of agreement (LoA) for power output (TEE 10.7%, LoA 54.1–50.6 W), V˙O2 (TEE 5.9%, LoA −0.57 to 0.63 L·min−1), and heart rate (TEE 2.4%, LoA −9.6 to 14.7 beats·min−1). Significant correlations were observed between [HHb]BP (r = .70) and AnT (r = .89) with 2000-m mean power. Conclusions: These results demonstrate a breaking point in [HHb] of the vastus lateralis muscle during the incremental test that is capable of distinguishing rowers with different performance levels. However, the high random error would compromise the use of [HHb]BP for training and testing in rowing.

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Anna K. Porter, Samantha Schilsky, Kelly R. Evenson, Roberta Florido, Priya Palta, Katelyn M. Holliday and Aaron R. Folsom

Background: This study assessed the independent associations between participation in self-reported sport and exercise activities and incident cardiovascular disease (CVD). Methods: Data were from 13,204 participants in the Atherosclerosis Risk in Communities Study cohort (1987–2015). Baseline sport and exercise activities were assessed via the modified Baecke questionnaire. Incident CVD included coronary heart disease, heart failure, or stroke. Multivariable-adjusted Cox proportional hazard models assessed the association of participation in specific sport and exercise activities at enrollment with risk of CVD. Results: During a median follow-up time of 25.2 years, 30% of the analytic sample (n = 3966) was diagnosed with incident CVD. In fully adjusted models, participation in racquet sports (hazard ratio [HR] 0.75; 95% confidence interval [CI], 0.61–0.93), aerobics (HR 0.75; 95% CI, 0.63–0.88), running (HR 0.68; 95% CI, 0.54–0.85), and walking (HR 0.89; 95% CI, 0.83–0.95) was significantly associated with a lower risk of CVD. There were no significant associations for bicycling, softball/baseball, gymnastics, swimming, basketball, calisthenics exercises, golfing with cart, golfing with walking, bowling, or weight training. Conclusions: Participation in specific sport and exercises may substantially reduce the risk for CVD.

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Zhiguang Zhang, Eduarda Sousa-Sá, João R. Pereira, Anthony D. Okely, Xiaoqi Feng and Rute Santos

Background: This study examined the associations between environmental characteristics of early childhood education and care (ECEC) centers and 1-year change in toddlers’ physical activity and sedentary behavior while at the centers. Methods: Data from 292 toddlers from the GET-UP! study were analyzed. Environmental characteristics of ECEC centers were rated using the Infant/Toddler Environment Rating Scale-revised edition at baseline. Children’s physical activity and sedentary behavior in the centers were assessed using activPAL devices, at baseline and at 1-year follow-up. Linear mixed models were performed to examine the associations between the environmental characteristics and change in the proportion of time spent in physical activity and sedentary behavior. Results: Compared with baseline, children spent a higher proportion of time in sedentary behavior (sitting) but a lower proportion of time in standing and physical activity (stepping) while at ECEC centers, at 1-year follow-up. The environmental characteristics “interaction” (B = −1.39; P = .01) and “program structure” (B = −1.15; P = .04) were negatively associated with change in the proportion of time spent in physical activity. Conclusion: Better “interaction” and “program structure” may preclude children’s physical activity from declining over time and may be considered important features to target in future interventions in ECEC centers aiming at promoting active lifestyles.

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Alireza Rabbani, Mehdi Kargarfard, Carlo Castagna, Filipe Manuel Clemente and Craig Twist

Purpose: To investigate the relationship between accumulated global positioning system–accelerometer-based and heart rate–based training metrics and changes in high-intensity intermittent-running capacity during an in-season phase in professional soccer players. Methods: Eleven male professional players (mean [SD] age 27.2 [4.5] y) performed the 30-15 Intermittent Fitness Test (30-15IFT) before and after a 5-wk in-season training phase, and the final velocity (VIFT) was considered their high-intensity intermittent-running capacity. During all sessions, Edwards training impulse (Edwards TRIMP), Banister TRIMP, Z5 TRIMP, training duration, total distance covered, new body load (NBL), high-intensity running performance (distance covered above 14.4 km·h−1), and very-high-intensity running performance (distance covered above 19.8 km·h−1) were recorded. Results: The players’ VIFT showed a most likely moderate improvement (+4.3%, 90% confidence limits 3.1–5.5%, effect size 0.70, [0.51–0.89]). Accumulated NBL, Banister TRIMP, and Edwards TRIMP showed large associations (r = .51–.54) with changes in VIFT. A very large relationship was also observed between accumulated Z5 TRIMP (r = .72) with changes in VIFT. Large to nearly perfect within-individual relationships were observed between NBL and some of the other training metrics (ie, Edwards TRIMP, Banister TRIMP, training duration, and total distance) in 10 out of 11 players. Conclusions: Heart rate–based training metrics can be used to monitor high-intensity intermittent-running-capacity changes in professional soccer players. The dose–response relationship is also largely detected using accelerometer-based metrics (ie, NBL) to track changes in high-intensity intermittent-running capacity of professional soccer players.

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Ashley M. Duguay, Todd M. Loughead and James M. Cook

The present study sought to address 2 limitations of previous athlete-leadership research: (a) Researchers have predominantly examined the shared nature of athlete leadership using aggregated approaches, which has limited our ability to examine differences in the degree of sharedness between teams, and (b) the limited availability of research related to dyadic predictors (i.e., qualities of the relation between 2 individuals) of athlete leadership. Therefore, social-network analysis was used to examine athlete leadership across multiple levels (i.e., individual, dyadic, and network) in 4 competitive female youth soccer teams (N = 68). Findings demonstrated differences in the degree to which athlete leadership was shared between the teams. Furthermore, multiple-regression quadratic-assignment procedures showed that skill nomination and formal leadership status were significant predictors of how often participants reported looking to their teammates for leadership.

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Michael L. Naraine

The sport industry has experienced significant technological change in its environment with the recent rise of Bitcoin and its underlying foundation, blockchain. Accordingly, the purpose of this paper is to introduce and conceptually ground blockchain in sport and discuss the implications and value proposition of blockchain to the sport industry. After a brief overview of blockchain and the technology stack, the mechanism is conceptually rooted in the network paradigm, a framework already known to the academic sport community. This treatment argues that the decentralized, closed, and dense mesh network produced by blockchain technology is beneficial to the sport industry. Notably, the article identifies blockchain’s capacity to facilitate new sources of revenue and improve data management and suggests that sport management and communication consider the value of blockchain and the technology stack as the digital footprint in the industry intensifies and becomes increasingly complex.