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Stefan Szymanski

Sport analytics promises to use Big Data and sophisticated statistical methods to identify effective strategies in sports—“the Moneyball moment.” However, much like alchemy, sport analytics is characterized by opacity and secrecy, and outside of baseball, evidence of success that would meet the usual scientific criteria is limited. An example is used to demonstrate that quite simple models can match more complex ones in terms of prediction. Like alchemy, sport analytics can deliver important advances in our understanding, but some problems need to be addressed. These include the need to incorporate theory, reconciling the pursuit of profit with scientific principles, and focusing on prediction as a measure of progress.

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Richard B. Kreider

Strength, conditioning, and nutrition play an important role in preparing athletes to perform to the best of their ability. For this reason, nearly all competitive teams employ strength and conditioning specialists to prepare their athletes for competition, and most teams have sport dietitians and/or nutrition consultants as part of their performance-enhancement team. Academic and professional preparation of strength and conditioning and sport-nutrition specialists in kinesiology programs has opened up a number of career opportunities for students and scholars. In addition, advances in technology have enhanced the ability of strength and conditioning specialists and sport nutritionists to monitor athletes during training and competition. This paper provides an overview of the history, professional preparation, program components, and general principals of strength and conditioning and sport nutrition and the impact they have had on high-level performance, as well as future trends in these fields.

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Angela Papadimitriou and Mark Perry

This systematic review aims to evaluate the efficacy of cognitive and behavioral interventions for improving fall-related psychological concerns. A systematic search yielded eight randomized controlled trials eligible for inclusion. All studies compared a cognitive and behavioral intervention with a control. The meta-analysis showed that cognitive and behavioral treatments had beneficial effects on fear of falling outcomes (lower score better) immediately after treatment (random-effects standardized mean difference [SMD]: −0.3, 95% confidence interval [CI] [−0.50, −0.10]) and at the longer term follow-up (random-effects SMD: −0.29, 95% CI [−0.49, −0.09]). Cognitive and behavioral treatments also showed a positive effect on falls efficacy outcomes (higher score better) immediately after treatment (fixed-effects SMD: 0.19, 95% CI [0.04, 0.34]) and over the longer term (fixed-effects SMD: 0.13, 95% CI [−0.00, 0.25]). However, the clinical significance of these effects on fear of falling and falls efficacy was unclear. Further work is required with best-practice comparators over a longer follow-up period.

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Roel De Ridder, Tine Willems, Jos Vanrenterghem, Ruth Verrelst, Cedric De Blaiser and Philip Roosen

Context: Although taping has been proven effective in reducing ankle sprain events in individuals with chronic ankle instability, insight into the precise working mechanism remains limited. Objectives: To evaluate whether the use of taping changes ankle joint kinematics during a sagittal and frontal plane landing task in subjects with chronic ankle instability. Design: Repeated measure design. Setting: Laboratory setting. Participants: A total of 28 participants with chronic ankle instability performed a forward and side jump landing task in a nontaped and taped condition. The taping procedure consisted of a double “figure of 6” and a medial heel lock. Main Outcome Measures: 3D ankle joint kinematics was registered. Statistical parametric mapping was used to assess taping effect on mean ankle joint angles and angular velocity over the landing phase. Results: For both the forward and side jump, a less plantar flexed and a less inverted position of the ankle joint were found in the preparatory phase till around touchdown (TD) in the taped condition (P < .05). In addition, for both jump landing protocols, a decreased dorsiflexion angular velocity was found after TD (P < .05). During the side jump protocol, a brief period of increased inversion angular velocity was registered after TD (P < .05). Conclusions: Taping is capable of altering ankle joint kinematics prior to TD, placing the ankle joint in a less vulnerable position at TD.

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Will Abbott, Callum Brashill, Adam Brett and Tom Clifford

Purpose: To investigate the effects of tart cherry juice (TCJ) on recovery from a soccer match in professional players. Methods: In a double-blind, placebo-controlled, crossover design, 10 male professional soccer players from the reserve team of an English Premier League Club (age 19 [1] y, height 1.8 [0.6] m, body mass 77.3 [6.4] kg) consumed 2 × 30-mL servings of TCJ or an isocaloric cherry-flavored control drink (CON) before and after a 90-minute match and 12 and 36 hours after the match. Muscle function (countermovement jump height and reactive strength index), subjective well-being, and subjective muscle soreness were measured before and 12, 36, and 60 hours after each match. Results: Countermovement jump height was similarly reduced in the days after the match after TCJ and CON supplementation, with the greatest loss occurring at 12-hour postmatch (−5.9% [3.1%] vs −5.4% [2.9%], of baseline values, respectively; P = .966; ηp2=.010). Decrements in reactive strength index were also greatest at 12-hour postmatch (TCJ −9.4% [8.4%] vs CON −13.9% [4.8%], of baseline values), but no group differences were observed at any time point (P = .097; ηp2=.205). Muscle soreness increased 12- to 60-hour postmatch in both groups, peaking at 12-hour postmatch (TCJ 122 [27] mm vs CON 119 [22] mm), but no group differences were observed (P = .808; ηp2=.024). No interaction effects were observed for subjective well-being (P = .874; ηp2=.025). Conclusions: TCJ did not hasten recovery after a soccer match in professional players. These findings bring into question the use of TCJ as a recovery aid in professional soccer players.

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Brendan T. O’Keeffe, Alan E. Donnelly and Ciaran MacDonncha

Purpose: To examine the test–retest reliability of student-administered (SA) health-related fitness tests in school settings and to compare indices of reliability with those taken by trained research-assistants. Methods: Participants (n = 86; age: 13.43 [0.33] y) were divided into 2 groups, SA (n = 45, girls = 26) or research-assistant administered (RA; n = 41, girls = 21). The SA group had their measures taken by 8 students (age: 15.59 [0.56] y, girls = 4), and the RA group had their measures taken by 8 research-assistants (age: 21.21 [1.38], girls = 5). Tests were administered twice by both groups, 1 week apart. Tests included body mass index, handgrip strength, standing broad jump, isometric plank hold, 90° push-up, 4 × 10-m shuttle run, back-saver sit and reach, and blood pressure. Results: Intraclass correlation coefficients for SA (≥.797) and RA (≥.866) groups were high, and the observed systematic error (Bland–Altman plot) between test 1 and test 2 was close to 0 for all tests. The coefficient of variation was less than 10% for all tests in the SA group, aside from the 90° push-up (24.3%). The SA group had a marginally lower combined mean coefficient of variation across all tests (6.5%) in comparison with the RA group (6.8%). Conclusion: This study demonstrates that, following familiarization training, SA health-related fitness tests in school-based physical education programs can be considered reliable.

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Sigridur L. Gudmundsdottir

Purpose: Insufficient sleep duration may affect athletic performance and health. Inconsistent sleep pattern also has negative health effects, but studies on athletes’ intraindividual sleep variability are scarce. The aim of this research was to compare total sleep time (TST) and variability (TST-variability), wakening after sleep onset, and sleep efficiency, during nights preceding early morning practices with other nights, and to investigate sleep characteristics of nights following a day with early morning only, evening only, or both a morning and an evening session in adolescent swimmers. Methods: Wrist-worn accelerometers were used to measure 1 week of sleep in 108 swimmers (mean age 16.1 [2.6] y) in Iceland. Adjusted regression analyses and linear mixed models were used to explore associations of training schedules with TST, TST-variability, wakening after sleep onset, and sleep efficiency. Results: Mean TST was 6:32 (h:min) (±39 min) and TST-variability was 63 minutes (±25 min). TST decreased and TST-variability increased with more early morning practices. TST preceding early training was 5:36 and 5:06 in <16- and ≥16-year-olds, respectively, shorter than on nights preceding later or no morning training (P < .001). Conclusion: Swimmers have extremely short TST preceding early morning sessions and increased TST-variability with more early morning sessions.

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Chih-Yen Chang and Tsung-Min Hung

Previous studies have revealed that several cortical signatures are associated with superior motor performance in sports, particularly precision sports. This review examined the strength of the evidence from these studies so that a clear conclusion could be drawn and a concrete direction for future efforts revealed. A total of 26 articles assessing the relationship between cortical activity and precision motor performance were extracted from databases. This review concluded that among the electroencephalographic components examined, only sensorimotor rhythm demonstrated a consistent and causal relationship with superior precision motor performance, whereas findings related to the left temporal alpha and frontal theta and alpha rhythms were not consistent and lacked the evidence needed to draw a causal inference for a role in superior precision motor performance. Future studies would benefit from methodological improvements including larger sample sizes, narrower skill-gap comparisons, evidenced-based and refined neurofeedback-training protocols, and consideration of ecological validity.

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Mandy Peacock, Julie Netto, Polly Yeung, Joanne McVeigh and Anne-Marie Hill

Pet ownership is associated with increased levels of physical activity (PA) in older adults. Studies have mainly focused on the association between PA and dog walking; however, broader aspects of pet ownership may influence PA. The purpose of this study was to explore the association between pet ownership and incidental and purposeful PA using a mixed methods approach. Participants’ (N = 15) PA was measured for 7 days using accelerometers and diaries. Semistructured interviews explored participants’ perspectives regarding pet-related activities. Participants’ mean (SD) daily step count was 14,204 (5,061) steps, and mean (SD) sedentary time per day was 8.76 (1.18) hr. Participants strongly concurred that their pets were an integral part of their daily lives. Incidental and purposeful PA resulted from participants undertaking pet care and socially interacting with their pets. Pets may interrupt sedentary behaviors by nudging older adults to engage in PA as part of their daily lived experience.

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Aymen Ben Othman, Mehdi Chaouachi, Issam Makhlouf, Jonathan P. Farthing, Urs Granacher, David G. Behm and Anis Chaouachi

Purpose: Whereas cross-education has been extensively investigated with adults, there are far fewer youth investigations. Two studies suggested that children had greater global responses to unilateral knee extensor fatigue and training, respectively, than adults. The objective of this study was to compare global training responses and cross-education effects after unilateral elbow flexion (EFlex) and leg press (LP) training. Methods: Forty-three prepubertal youths (aged 10–13 y) were randomly allocated into dominant LP (n = 15), EFlex (n = 15) training groups, or a control (n = 13). Experimental groups trained 3 times per week for 8 weeks and were tested pretraining and posttraining for ipsilateral and contralateral 1-repetition maximum LP; knee extensor, knee flexors, elbow flexors; and handgrip maximum voluntary isometric contractions (MVIC), and countermovement jump. Results:In comparison to no significant changes with the control group, dominant elbow flexors training demonstrated significant ( P < .001) improvements only with ipsilateral and contralateral upper body testing (EFlex MVIC [15.9–21.5%], EFlex 1-repetition maximum [22.9–50.8%], handgrip MVIC [5.5–13.8%]). Dominant LP training similarly exhibited only significant ( P < .001) improvements for ipsilateral and contralateral lower body testing (LP 1-repetition maximum [59.6–81.8%], knee extensor MVIC [12.4–18.3%], knee flexor MVIC [7.9–22.3%], and countermovement jump [11.1–18.1%]). Conclusions: The ipsilateral and contralateral training adaptations in youth were specific to upper or lower body training, respectively.