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L-citrulline (CIT) supplementation seems to improve resistance training performance; yet, whether malate has additive ergogenic effects when combined with CIT is unknown. This randomized, double-blind, placebo-controlled crossover trial aimed to compare the acute effects of CIT versus citrulline malate (CMA) supplementation on neuromuscular performance and exertion and emotional perceptions in young, trained men and women. 43 (21 women; 24.2 ± 3.7 years) participants ingested a placebo, CIT (5.3 g of CIT), or CMA (5.3 g of CIT, 2.7 g of malate) 45 min before three experimental sessions in a counterbalanced manner. We evaluated the upper and lower limb maximal neuromuscular and ballistic performance through the two-point method and countermovement jump. Strength-endurance was assessed across three sets of 10 repetitions in the squat and bench press exercises. Exertion and emotional perceptions were evaluated before and after the assessment and during the strength-endurance assessment. CIT and CMA supplementation did not enhance maximal neuromuscular performance (all p ≥.061, η p 2 ≤.066), or ballistic strength (all p ≥.348, η p 2 ≤.025). Neither CIT nor CMA supplementation improved strength-endurance as observed in the total number of repetitions (all p ≥.590, η p 2 ≤.013), repetitions before reaching velocity loss threshold (all p ≥.623, η p 2 ≤.010), mean velocity (all p ≥.792, η p 2 ≤.004), mean velocity decline (all p ≥.293, η p 2 ≤.029), and mean velocity maintenance (all p ≥.393 η p 2 ≤.022), or exertion and emotional perceptions (both p ≥.306, η p 2 ≤.028). In conclusion, CIT and CMA supplementation may not increase the neuromuscular performance during low- to moderate-volume resistance training sessions in young, trained adults. This trial was registered at ClinicalTrials.gov (No. NCT05183893). [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to analyze the effects of bilateral and unilateral plyometric-training (PT) programs on jumping, sprinting, and change-of-direction (COD) ability in male postpubertal basketball players. Methods: Forty-three young male basketball players (14.2 [1.2] y), from 4 squads belonging to an elite basketball club, were randomly assigned to 1 of 3 groups: (1) bilateral PT group (BG), (2) unilateral PT group (UG), and (3) control group (CG). The experimental groups followed a PT program twice weekly for 6 weeks, with BG and UG performing 2- and 1-legged jumps, respectively. Both groups completed the same number of vertical, horizontal, cyclic, and acyclic jumps. Pretraining and posttraining measurements included (1) countermovement jump (CMJ), (2) unilateral CMJ (CMJL and CMJR), (3) horizontal jump (HJ), (4) unilateral HJ (HJL and HJR), (5) straight-line sprint in 20 m (T20), and (6) V-Cut COD test (V-Cut). Results: CMJ, CMJL, and CMJR were significantly improved by BG and UG (P <.001), while CG did not change. Both the BG and the UG improved their performance significantly (P <.01) in HJL and HJR, but only BG significantly increased (P <.05) HJ and showed significantly greater improvements than CG. Furthermore, only BG improved V-Cut performance (P =.03). Neither group increased T20. CG did not improve in any tests. Conclusions: BG enhances single-leg and double-leg jump performance in vertical and horizontal directions, as well as COD ability. In contrast, an equivalent volume of unilateral PT only improves vertical jumps and unilateral HJs. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the impact of a 6-week upper-body plyometric-training (PT) program with varying volumes on the immunoendocrine, physiological parameters, and physical performance adaptations in male volleyball players. Methods: Twenty-four trained college players were randomly allocated into 3 groups with 8 participants. Each group performed 5 exercises at maximal effort with differences in volume: low (3 sets of 7 repetitions), moderate (3 sets of 10 repetitions), and high (3 sets of 13 repetitions). The training program lasted 6 weeks with participants undertaking 3 sessions of PT per week. Results: Following the intervention, all groups exhibited significant (P =.001) improvements in physical and physiological parameters, as well as skill-based performances, with effect sizes ranging from small to very large. Comparative analysis of individual changes indicated that the high-volume group resulted in greater adaptive responses in the medicine-ball throw (P =.004), peak (P =.001) and average (P =.022) power output, push-ups (P =.001), and strength (P =.032) compared with the low-volume group. No significant between-groups difference (P >.05) was observed regarding immunoendocrine measures, reaction time, attacking, and serving skills. Conclusions: The findings indicate that short-term upper-body PT positively influenced performance adaptations, emphasizing that the adaptive response to PT depends on the varying volumes. The study proposes that integrating higher volumes of PT results in more significant adaptive responses among volleyball players with the same immunoendocrine responses as the other training volumes. [ABSTRACT FROM AUTHOR]

Context: The single-leg hop is based solely on performance with no measure of movement quality. The purpose of this study was to (1) develop a real-time screening tool to capture single-leg functional performance and movement quality and (2) to provide preliminary validation (criterion validity) of a trained clinician's real-time movement quality assessment with 3D kinematics. Study Design: Cross-sectional. Methods: Fifty-nine adolescent athletes volunteered (15.2 [1.1] y, 165.8 [9.2] cm, and 61.5 [13.9] kg, 51 females and 8 males). Each participant performed 3 trials of the single-leg hop on their dominant leg. A 3-dimensional inertial measurement system was used to capture knee joint kinematics. A movement quality checklist for use during a single-leg hop (movement quality single-leg hop) was developed to score biomechanical errors based on lower-extremity injury risk factors. Four criteria were developed for the checklist: (1) knee valgus, (2) foot rotation, (3) lateral trunk flexion, and (4) erect posture. An independent t test was conducted for each dependent variable (knee flexion displacement and knee abduction displacement) by each independent variable (movement category presence of (1) lateral trunk flexion, (2) knee valgus, (3) foot rotation, and (4) erect posture/sound during landing [yes or no]). The alpha level was set at α <.05 for all analyses. Results: Knee flexion displacement was significantly decreased (P <.001, mean difference 9.40 [1.88]) and knee abduction displacement was significantly increased (P <.001, mean difference 9.41 [0.47]) for those who had knee valgus documented by the clinician. In additional, for those with visually documented erect posture/sound of landing, there was a significant decrease in knee flexion displacement (P <.001, mean difference 10.13 [2.34]). Conclusion: The movement quality single-leg hop checklist has shown promising preliminary validation (criterion validity) for clinicians to assess movement quality. Increased knee abduction and decreased knee flexion are common risk factors associated with knee injuries and this clinician friendly real-time checklist may highlight individuals who are at risk of sustaining a knee injury. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to compare kinematic data of the frontal trunk, pelvis, knee, and summated angles (trunk plus knee) among categorized grades using the single-leg squat (SLS) test, to classify the SLS grade, and to investigate the association between the SLS grade and the frontal angles using smartphone-based markerless motion capture. Methods: Ninety-one participants were categorized into 3 grades (good, reduced, and poor) based on the quality of the SLS test. An automated pose estimation algorithm was employed to assess the frontal joint angles during SLS, which were captured by a single smartphone camera. Analysis of variance and a decision tree model using classification and regression tree analysis were utilized to investigate intergroup differences, classify the SLS grades, and identify associations between the SLS grade and frontal angles, respectively. Results: In the poor group, each frontal trunk, knee, and summated angle was significantly larger than in the good group. Classification and regression tree analysis showed that frontal knee and summated angles could classify the SLS grades with a 76.9% accuracy. Additionally, the classification and regression tree analysis established cutoff points for each frontal knee (11.34°) and summated angles (28.4°), which could be used in clinical practice to identify individuals who have a reduced or poor grade in the SLS test. Conclusions: The quality of SLS was found to be associated with interactions among frontal knee and summated angles. With an automated pose estimation algorithm, a single smartphone computer vision method can be utilized to compare and distinguish the quality of SLS movement for remote clinical and sports assessments. [ABSTRACT FROM AUTHOR]

Context: Clinical balance assessments vary in reliability due to subjectivity in their scoring. A valid and objective accelerometer-based smartphone evaluation could benefit patients, clinicians, and researchers. Objective: Our objective was to assess the validity and reliability of smartphone-based standing balance. Design: A repeated-measures study was conducted with 23 healthy young adult participants across 2 sessions ∼7 days apart. Methods: Participants completed 30-second standing trials during tandem-stance eyes-open, tandem-stance eyes-closed, single-leg eyes-open, and single-leg eyes-closed conditions. Android and iOS smartphones were placed vertically on the lower back via a belt with 3 retroreflective markers attached and tracked by an 8-camera motion capture system. Sway path, range, and area were calculated from smartphone accelerometer and marker data. We assessed reliability using intraclass correlation coefficients (ICC[2,k]) and validity using Pearson r correlations between the marker and smartphones from visit 1. Results: Across eyes-open conditions, Android (ICC =.84–.96), iOS (ICC =.82–.98), and marker-based (ICC =.84–.95) assessments demonstrated good to excellent reliability. Across eyes-closed conditions, Android (ICC =.41–.87), iOS (ICC =.34–.79), and marker-based (ICC =.31–.87) assessments demonstrated poor to good reliability. Correlations between smartphones and the marker data were moderate to very high (r =.56–.97). Conclusions: The smartphone-based assessment was valid and reliable, indicating that clinicians and researchers can implement this method to measure balance with the opportunity for remote administration and increased patient tracking across various recovery timepoints. [ABSTRACT FROM AUTHOR]

Background: The aims of this cross-sectional study were to (a) assess actigraphy-based sleep parameters (total sample and gender differences), (b) assess differences in morphological parameters and physical function between short- versus normal-sleepers and poor- versus good-sleepers, and (c) assess the possible correlations between sleep variables and morphological and physical function parameters in older subjects. Methods: This study enrolled 42 healthy older participants (60–80 years). Participants completed the following clinical evaluations: (1) whole-body dual-energy X-ray absorptiometry to assess the appendicular skeletal muscle mass index; (2) magnetic resonance imaging acquisition to determine the cross-sectional muscle area of thigh muscles and intermuscular adipose tissue; (3) risk of fall assessment through the mini-Balance Evaluation Systems Test; (4) strength assessment: (a) chair stand test and (b) handgrip strength test; (5) sleep monitoring by actigraphy to assess total sleep time, sleep efficiency, wake after sleep onset, sleep latency, fragmentation index, mobile time, and subjective sleep quality. Results: 31.0% of subjects were short-sleepers (total sleep time < 6 hr), 19.1% were poor-sleepers (sleep efficiency < 85%), and gender differences were detected in mobile time (males: 15.8 ± 6.0 and females: 13.4 ± 6.8; p <.001) and fragmentation index (males: 35.3 ± 14.3 and females: 29.6 ± 14.6; p <.001); no significant differences were observed between groups (short- vs. normal-sleepers and poor- vs. good-sleepers) in morphological and physical function variables; correlation analysis showed that sleep latency negatively correlated with Mini-Balance Evaluation Systems Test (r = −.352; p =.022) and a positive correlation was detected between cross-sectional muscle area and mobile time (r =.349, p =.023). Conclusion: No differences were observed in morphological and function parameters between good- versus poor-sleepers, those subjects with worse sleep onset latency (i.e., longer time to fall asleep) registered higher for risk of fall. The potential role of sleep in the physiological mechanisms of muscular aging must be explored through cross-sectional cohort studies with a larger population. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effects of walking-only intervention (walking was the only exercise in which people participated) on physical function, fall-related outcomes, and health-related quality of life in community-dwelling older adults. We conducted a systematic search across five electronic databases, assessing risk of bias using Minds Manual for Guideline Development. Meta-analyses were performed, and pooled standardized mean differences were calculated. Nine studies (a total of 1,309 participants) were included, showing that walking-only interventions improved walking endurance (standardized mean difference: 1.11, 95% confidence interval: [0.08, 2.15]) and health-related quality of life (standardized mean difference: 0.71, 95% confidence interval: [0.18, 1.25]). However, there were no significant improvements in other outcomes. The certainty of the evidence based on the Grading of Recommendations, Assessment, Development, and Evaluation approach for all outcomes was graded as very low, primarily due to significant inconsistency and imprecision. Our results suggest that walking-only intervention can be effective for enhancing walking endurance and health-related quality of life for community-dwelling older adults. Further studies are required to investigate the effects of walking-only intervention. This need stems from the limited number of randomized controlled trials, heterogeneous intervention settings and results, and the very low certainty of the evidence. [ABSTRACT FROM AUTHOR]

Background: The lumbar extensor muscles (LEMs) play an important role in body posture and physical function in older adults. Because lumbar extensor strength decreases more rapidly than limb muscle strength with age, it should be evaluated to aid healthy aging. This study investigated the association between LEM strength and physical performance in community-dwelling older adults. Methods: This prospective observational cohort study of spinal sarcopenia (SarcoSpine) was conducted at a single center. One hundred and ten consecutive individuals who completed the baseline survey, including conventional sarcopenic indices, lumbar spine three-dimensional magnetic resonance imaging, isokinetic lumbar extensor strength, and physical performance tests (Short Physical Performance Battery, Berg Balance Scale, and Back Performance Scale [BPS]), were enrolled. A multivariate linear regression analysis was performed to determine the variables for evaluating their association with LEM strength. Results: Among the conventional sarcopenic indices, gait speed was significantly correlated with Short Physical Performance Battery results and Berg Balance Scale score in men and women. Handgrip strength was significantly correlated with the BPS score for both sexes. In the multivariable linear regression, age (β = −2.12, p <.01) and BPS score (β = −3.54, p =.01, R2 =.29) were independent indicators of LEM strength. Conclusions: Our findings reveal the substantial association between LEM strength and BPS score in older women. The targeted intervention aimed at improving the LEMs strength would be needed to enhance physical performance in the aging population. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the role of antiphase trunk motion during quiet stance while maintaining constant visual and support surface conditions. Eyes-open quiet stance trials were performed on a firm support surface while wearing a rigid hip-knee orthotic brace that reduced antiphase trunk motion. Amplitude spectral density, coherence, and cophase were compared for hip-locked, hip-unlocked, and no-brace conditions. Amplitude spectral density calculations showed that trunk and leg sway velocities, and ankle torque (AT) decreased when antiphase trunk sway was allowed. Coherence and cophase estimates identified in-phase trunk-legs sway below 1 Hz and antiphase at higher frequencies. Legs-AT cophase calculations showed that the legs lagged the application of AT at all frequencies, while trunk-AT cophase showed the trunk lagged AT below 1 Hz and led AT at higher frequencies. The results demonstrate that antiphase trunk sway helps reduce sway velocity and AT. Furthermore, the trunk-leading cophase relationship with AT showed that antiphase trunk motion occurred before AT was applied. This implies that antiphase trunk motion facilitates changes in sway direction and helps regulate sway velocity. The results have significant implications for predicting postural control deficiencies due to injury, disease, and aging. [ABSTRACT FROM AUTHOR]

This study investigates the specific influence of step frequency (SF) and speed on the coordination between pelvic and thigh movements. Eight recreational male runners ran at different SFs and speeds on an instrumented treadmill. The coordination between the pelvis and thigh segments was analyzed using modified vector coding in the sagittal and frontal planes (FPs). Our findings show that hip range of motion increases as a function of SF in the sagittal plane. Pelvic tilt plays a compensatory role in hip extension, particularly at lower SFs. In the FP, pelvic roll increased at lower SFs, whereas the thigh abduction angle was participant dependant. Coordination analysis showed that thigh movements dominated the sagittal plane motion, which was simplified at higher SF. At low SF, the pelvic movements were increased and anticipated, playing a more dominant role in explaining motion. In the FP, pelvic movements dominated the motion. The increase in pelvic motion at low SFs stretches the hip flexors further and for a longer period. The link between SF, pelvic motion, and the risks of running-related injuries in the sagittal and FP is considered. Understanding these could help athletes and sports professionals optimize performance and reduce injury risk. [ABSTRACT FROM AUTHOR]

Jones fracture is a common injury in soccer players, caused by overload on the fifth metatarsal (M5) that can occur during crossover cutting. This study aimed to investigate the effects of the hip internal rotation (HIR) range in passive and dynamic conditions and foot progression angle (FPA) on the forces applied to the M5 during crossover cutting. The study included 20 men with experience playing soccer. The passive HIR was measured in the prone position. A 3-dimensional motion analysis system, force plates, and Footscan were used to measure the angle of the lower limb, including dynamic HIR, FPA, and plantar pressure to the M5, during crossover cutting in the 45° direction. Pearson correlation coefficient was measured to examine the relationship between variables. Passive and dynamic HIR were not related to the plantar pressure on the M5 (P >.05). However, increased FPA in movement direction correlated with a reduction in plantar pressure on the M5 (r = −.56, P <.01). Minimizing the FPA with respect to the new direction during crossover cutting reduced plantar pressure on the M5 and thus could prevent Jones fracture. [ABSTRACT FROM AUTHOR]

Purpose: Although previous studies have compared strength-training adaptations between free weights (FW) and machine-guided exercises, those studies did not use a Smith machine (SM), which most closely replicates the exercises performed with FW. Thus, the aim of the present study was to investigate the chronic effects of strength-focused, velocity-based training regimens using FW versus SM. Methods: Thirty-seven sport-science students (14 female) were assigned, balanced by sex and relative strength, to either an FW or SM training group. The training program lasted 8 weeks (2 sessions/wk), and participants performed 4 sets per exercise (back squat and bench press) at 70% of their 1-repetition maximum with moderate effort levels (20%–25% velocity loss). Load–velocity profile parameters (load-axis intercept, velocity-axis intercept, and area under the load–velocity relationship line), cross-sectional areas of the vastus lateralis and pectoralis major muscles, and the number of repetitions to failure in the bench-press exercise were assessed before and after the training program. Mechanical variables were assessed using both FW and SM. Results: All variables, with the exception of back-squat velocity-axis intercept (P =.124), improved in both training groups. The changes in load-axis intercept and area under the load–velocity relationship line were more pronounced when the training and testing conditions matched. Failure in the bench-press exercise and cross-sectional areas of the vastus lateralis and pectoralis major showed comparable improvements for both training groups, while velocity-axis intercept tended to improve more in the SM group. Conclusions: The general population, unconcerned with the specificity of strength adaptations, can choose a training modality (FW or SM) based on personal preferences. [ABSTRACT FROM AUTHOR]

Background: In high-performance sport, the support provided by sport scientists and other staff can be a valuable resource for coaches and athletes. Purpose: We propose and detail here the approach of "minimal, adequate, and accurate" sport-science support to ensure that programs of work and solutions are both economical and effective. Methods: Our support provision advocates for utilization of "minimal" resources (employing the least amount of time, tools, and funding) necessary to achieve the desired outcomes. We strive for "adequate" information that fulfills specific objectives without excess and with the requirement that methods and data used are "accurate" (valid and reliable). To illustrate the principles of this approach, we outline a real-world example of supporting 100-m track (athletics) sprinters preparing and competing in an international competition. The provision of performance support emphasizes an integrated approach, combining knowledge and insights from multiple sport-science disciplines. The key facets managed under this approach are (1) neuromuscular readiness, (2) wellness monitoring, (3) movement observation, (4) motivation, (5) biomechanics and performance analysis, and (6) qualitative feedback. These facets are based on the specific performance determinants and influencing factors of an event (100-m dash). Conclusions: Application of this quantitative and qualitative approach can enhance the ability to make informed decisions. Nevertheless, the approach must be planned, evaluated, and refined on a regular basis to enable effective decision making in sport-science support. The 3-element approach of "minimal, adequate, and accurate" should be codesigned and supported by the athletes, coaches, and staff to ensure successful implementation. [ABSTRACT FROM AUTHOR]

Purpose: This study's purpose was to investigate the midterm effects of alternative set configurations (cluster [CL] and rest redistribution [RR]) on lower- and upper-body neuromuscular capacities in female athletes. Method: Twenty team-sport female athletes were randomly assigned to a CL (n = 10) or RR (n = 10) training group. The study protocol comprised 2 pretests, 12 training sessions, and a posttest. Both groups engaged in identical exercises (squat and bench press), load intensity (75% of 1-repetition maximum), and volume (18 repetitions per exercise). The distinction between the groups lay in the total session rest time: The CL group had 23 minutes (3 sets of 6 repetitions with 30 s of intraset rest every 2 repetitions and 3 min of interset rest), whereas the RR group had 17 minutes (9 sets of 2 repetitions with 45 s of interset rest). Countermovement-jump height and load–velocity relationship variables (load-intercept, velocity-intercept, and area under the load–velocity relationship line) were assessed during the squat and bench-press exercises. Results: All dependent variables revealed greater values at posttest compared with pretest (P ≤.040; averaged Hedges g = 0.35 for CL and 0.60 for RR), but time × group interactions never reached statistical significance (P ≥.144). Likewise, the comparison of the magnitude of changes between the 2 groups revealed only trivial differences, except for a small greater change in bench-press area under the load–velocity relationship line for RRG (Hedges g = 0.40). Conclusions: RR is a more efficient strategy than CL for inducing strength gains in female athletes. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to compare the gross motor skills of children with a chronic physical illness with those of their healthy peers. Methods: Data for children with a chronic physical illness come from the Multimorbidity in Children and Youth Across the Life Course study, and data from children without a physical illness come from the Health Outcomes and Physical Activity in Preschoolers study. Multimorbidity in Children and Youth Across the Life Course and Health Outcomes and Physical Activity in Preschoolers included children ages 3–5 years and administered the Peabody Development Motor Scales-second edition. Participants were sex and age matched (20 male and 15 female pairs; Mage = 54.03 [9.5] mo). Results: Gross motor skills scores were "below average" for 47% of children with a physical illness compared with 9% of children without a physical illness (P =.003). Matched-paired t tests detected significant differences in total gross motor scores (dz = −0.35), locomotor (dz = −0.31), and object control (dz = −0.39) scores, with healthy children exhibiting better motor skills, and no significant difference in stationary scores (dz = −0.19). Conclusions: This skill gap may increase burden on children with physical illness and future research should assess gross motor skills longitudinally to establish whether the gap widens with age. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the performance of healthy Chilean children aged 3–10 years in the 6-minute walking test (6MWT) and cardiometabolic risk variables and to determine sex- and age-specific reference values. Methods: This study involved 1165 healthy children (age = 6.36 [1.70] y old). The 6MWT was used to evaluate exercise performance. Furthermore, anthropometric measures were collected, like weight, height, body mass index, waist circumference, and skin folds. Resting heart rate and blood pressure (BP) were also evaluated. Results: The prevalence of overweight and obesity was 35.0% and 25.4% in preschoolers and 29.0% and 36.2% in school-age children, respectively, showing significant differences (P <.05) between age groups. The distance walked (6-min walk distance) increased significantly year on year at ages from 3 to 10 years. According to the regression analysis, 6MWT performance was positively related to age, systolic BP, and height, whereas it was negatively related to ∑4 skinfold fat, resting heart rate, diastolic BP, and waist circumference. Conclusions: This study provides a reference equation and an age- and sex-adjusted percentile curve to assess the predicted 6MWT performance in a cohort of prepubertal Chilean children. The 6-minute walk distance depends mainly on age; however, other variables, such as resting heart rate, BP, skinfold fat, and waist circumference, add significant information and should be taken into account. [ABSTRACT FROM AUTHOR]

Background: Preexercise caffeine intake has proven to exert ergogenic effects on cycling performance. However, whether these benefits are also observed under fatigue conditions remains largely unexplored. We aimed to assess the effect of caffeine ingested during prolonged cycling on subsequent time-trial performance in trained cyclists. Methods: The study followed a triple-blinded, randomized, placebo-controlled cross-over design. Eleven well-trained junior cyclists (17 ± 1 years) performed a field-based 8-min time trial under "fresh" conditions (i.e., after their usual warm-up) or after two work-matched steady-state cycling sessions (total energy expenditure∼20 kJ/kg and ∼100 min duration). During the latter sessions, participants consumed caffeine (3 mg/kg) or a placebo ∼60 min before the time trial. We assessed power output, heart rate, and rating of perceived exertion during the time trial and mood state (Brunel Mood Scale) before and after each session. Results: No significant condition effect was found for the mean power output attained during the time trial (365 ± 25, 369 ± 31, and 364 32 W for "fresh," caffeine, and placebo condition, respectively; p =.669). Similar results were found for the mean heart rate (p =.100) and rating of perceived exertion (p = 1.000) during the time trial and for the different mood domains (all p >.1). Conclusions: Caffeine intake during prolonged exercise seems to exert no ergogenic effects on subsequent time-trial performance in junior cyclists. Future studies should determine whether significant effects can be found with larger caffeine doses or after greater fatigue levels. [ABSTRACT FROM AUTHOR]

Purpose: To correlate speed and heat scores with anthropometric variables and lower-limb strength and power in professional surfers. Methods: A total of 19 men participated in simulated competitions on different days. All surfed waves were scored, and each athlete's best 2 were used for their total heat score. Speed values were extracted by global positioning system and adjusted by Z score. Squat jump, countermovement jump, and drop jump were executed. Anthropometric variables and 1-repetition maximum (1RM) in the half squat were measured. Pearson product–moment correlation was used to analyze the relationships. Results: Height had a significant (P <.05) inverse association with speed indicators (r = −.36 to −.68), and body mass index had a moderate association with maximum wave speed of the highest score. Significant correlations with moderate to large magnitudes were found between maximum speed and vertical jumps (r =.46 to.56), average speed and vertical jumps (r =.48 to.59), and both maximum and average speed with 1RM (r =.52–.53). Athletes' best score and total heat score showed moderate to large associations with vertical jumps and 1RM (r =.48–.64), whereas second scores were correlated with the reactive strength index of the drop jump (r =.48) and 1RM (r =.51). Conclusions: Shorter surfers with lower center of gravity and those with superior lower-limb strength and power achieved greater speed and higher scores. Accordingly, surf coaches may consider prescribing dynamic strength and balance training based on an athlete's profile to improve performance. [ABSTRACT FROM AUTHOR]

Purpose: To compare the acute effects on mechanical, metabolic, neuromuscular, and muscle contractile responses to different velocity-loss (VL) thresholds (20% and 40%) under distinct blood-flow conditions (free [FF] vs restricted [BFR]) in full squat (SQ). Methods: Twenty strength-trained men performed 4 SQ protocols with 60% 1-repetition maximum that differed in the VL within the set and in the blood-flow condition (FF20: FF with 20% VL; FF40: FF with 40% VL; BFR20: BFR with 20% VL; and BFR40: BFR with 40% VL). The level of BFR was 50% of the arterial occlusion pressure. Before and after the SQ protocols, the following tests were performed: (1) tensiomyography, (2) blood lactate, (3) countermovement jump, (4) maximal voluntary isometric SQ contraction, and (5) performance with the load that elicited a 1 m·s−1 at baseline measurements in SQ. Results: No "BFR × VL" interactions were observed. BFR protocols resulted in fewer repetitions and lower increases in lactate concentration than FF protocols. The 40% VL protocols completed more repetitions but resulted in lower mechanical performance and electromyography median frequency during the exercise than the 20% VL protocols. At postexercise, the 40% VL protocols also experienced greater blood lactate concentrations, higher alterations in tensiomyography-derived variables, and accentuated impairments in SQ and countermovement-jump performances. The 20% VL protocols showed an increased electromyography median frequency at postexercise maximal voluntary isometric contraction. Conclusions: Despite BFR-accelerated fatigue development during exercise, a given VL magnitude induced similar impairments in the distinct performance indicators assessed, regardless of the blood-flow condition. [ABSTRACT FROM AUTHOR]

Purpose: This study sought to investigate the efficacy of Tabata-style high-intensity interval training (T-HIIT) on athletic performance in judoka and to determine the impact of the fecal organic acid profile before training on the improvement of athletic performance. Methods: Twenty males from Aichi University Judo Club (10 high-level competitors and 10 others) were included. Physical fitness tests such as the Uchikomi shuttle run, countermovement jump, squat jump, and chin-ups using a judo uniform were performed before and after T-HIIT. Fecal samples were collected before T-HIIT to measure the fecal concentration of organic acids. The fecal characteristics were categorized using the Bristol Stool Scale. Results: The mean number of repetitions of the Uchikomi shuttle run test significantly increased for all judoka following T-HIIT. However, improvements in other physical fitness tests varied, with some judoka showing improvements while others did not. The changes in countermovement jump (r = −.48, P =.029) and chin-ups using a judo uniform (r = −.45, P =.045) after T-HIIT were significantly negatively correlated with the fecal concentrations of succinic acid before T-HIIT. There was a significant correlation between the Bristol Stool Scale score and fecal concentrations of succinic acid (r =.45, P =.044). Compared with other compounds, the fecal concentrations of acetic acid and propionic acid were significantly greater in high-level competitors, while succinic acid concentrations tended to be lower. Conclusions: T-HIIT effectively improved the specialized endurance of the judoka. Modifying the fecal organic acid profile, especially the fecal succinic acid concentration, may enhance the efficacy of athletic performance improvements achieved by T-HITT. [ABSTRACT FROM AUTHOR]

Purpose: To investigate differences between females and males at lactate thresholds 1 (LT1) and 2 (LT2). Methods: Twenty-four female and twenty male participants performed an incremental cycle-ergometer test until exhaustion, where LT1 and LT2 were determined in each volunteer. Results: Power output at LT1 and LT2 was lower in females than in males (P <.001). In addition, power output relative to peak power was higher in females at LT1 and LT2 (P <.001). However, heart rate was higher in females than males at LT1 and LT2 (P =.008). Furthermore, the heart rate relative to maximal heart rate was higher in females compared with males at LT1 and LT2 (P =.002). Conclusion: Females and males may be in a different metabolic situation at the same percentage of maximum. This study helps to reduce sex bias in science, and future guidelines should consider establishing exercise prescription recommendations according to sex. Clinical Trial: NCT06104150. [ABSTRACT FROM AUTHOR]

Physical activity levels during skilled nursing facility (SNF) rehabilitation fall far below what is needed for successful community living and to prevent adverse events. This feasibility study's purpose was to evaluate the feasibility, acceptability, and preliminary effectiveness of an intervention designed to improve physical activity in patients admitted to SNFs for short-term rehabilitation. High-Intensity Rehabilitation plus Mobility combined a high-intensity (i.e., high weight, low repetition), progressive (increasing in difficulty over time), and functional resistance rehabilitation intervention with a behavioral economics-based physical activity program. The behavioral economics component included five mobility sessions/week with structured goal setting, gamification, and loss aversion (the idea that people are more likely to change a behavior in response to a potential loss over a potential gain). SNF physical therapists, occupational therapists, and a mobility coach implemented the High-Intensity Rehabilitation plus Mobility protocol with older Veterans (n = 18) from a single SNF. Participants demonstrated high adherence to the mobility protocol and were highly satisfied with their rehabilitation. Treatment fidelity scores for clinicians were ≥95%. We did not observe a hypothesized 40% improvement in step counts or time spent upright. However, High-Intensity Rehabilitation plus Mobility participants made clinically important improvements in short physical performance battery scores and gait speed from admission to discharge that were qualitatively similar to or slightly higher than historical cohorts from the same SNF that had received usual care or high-intensity rehabilitation alone. These results suggest a structured physical activity program can be feasibly combined with high-intensity rehabilitation for SNF residents following a hospital stay. [ABSTRACT FROM AUTHOR]

The stiffness of the supporting leg may alter the energy transfer to the trunk and lower extremities of the kicking leg, which may affect kick performance. This study aimed to clarify whether the stiffness of the supporting leg affects the trunk kinematics during kicking and kicking performance in soccer players. Twenty-two male collegiate soccer players participated in the study. The data for the stiffness properties of the supporting leg and trunk kinematics were obtained and calculated using a 3-dimensional motion analysis system. The results showed that a greater leg stiffness of the supporting leg was associated with a lower trunk rotation angle during kicking. There were no significant correlations between the maximum swing speed and the stiffness of the supporting leg (P <.05). These results suggest that stiffness of the supporting leg may restrain trunk rotation during the kicking motion. However, the lack of a relationship with swing speed indicates the need for further investigation into its effects on kicking performance. [ABSTRACT FROM AUTHOR]

The effects of hip position and posture on scapular kinematics have yet to be explored. The purpose of this study was to measure differences in scapular kinematics with changing hip position. Scapular kinematics were measured during scapular plane humeral elevation. Twenty-four subjects were required to elevate the dominant arm up to 120° in the following randomized conditions: standing, seated, seated ipsilateral hip flexion, and seated contralateral hip flexion. Two-way analyses of variance were used to evaluate effects of shoulder elevation and hip position on scapular upward rotation, posterior tilt (PT), and external rotation. For external rotation, there was no significant interaction (P =.714) and no main effect of elevation (P =.618) or condition (P =.390). For PT, there was no significant interaction (P =.693) but significant main effects of elevation (P <.001) and condition (P <.001), with the greatest PT in standing. For upward rotation, there was no significant interaction (P =.698), a significant main effect of elevation (P <.001), and no significant effect of condition (P =.726). The effect on PT may not be clinically significant. These results may serve as a baseline measurement of healthy scapular kinematics across hip positions. [ABSTRACT FROM AUTHOR]

An overhead throwing motion is a common gross motor skill often taught in early childhood to improve physical activity participation. Yet, research investigating motor efficiency in overhead throws often focuses on improving performance in trained individuals. This project compares kinematic sequencing between trained and untrained youth. After a brief warm-up, untrained high school students (N = 9) and trained high school and college students (N = 10) threw a weighted tennis ball for accuracy (N = 10 throws). Upper extremity angular velocities were collected using 3-dimensional inertial sensor motion capture. Kinematic sequencing of joints and segments (pelvis, trunk, shoulder, elbow, and wrist) was assessed using Kruskal–Wallis test; Friedman and Wilcoxon tests identified group differences between sequences. Seven independent kinematic sequences were identified (N = 2 unique trained; N = 3 unique untrained; N = 2 shared). The rankings for the trained group maintained a mostly consistent pattern with only elbow and wrist joints producing similar rankings. The untrained group lacked that consistency with similar rankings of elbow versus wrist and shoulder versus elbow. Trained individuals threw with a more efficient proximal-to-distal sequencing pattern than the untrained participants, specifically at the trunk and shoulder. Continuous training of gross motor skills beyond initial skill development is necessary to maintain motor proficiency. [ABSTRACT FROM AUTHOR]

Most injuries that dancers sustain are to the lower extremities, specifically the foot and ankle region. Numerous potential risk factors have been examined for dancer injuries such as technical mistakes and fatigue. The purpose of this study was to compare landing kinematics and kinetics during jumps that are common in dance pre and postfatigue. Ten adolescent advanced level dancers participated in this study. Subjects completed 3 split leaps and 3 center leaps before and after a fatigue protocol performed on a stationary bike. Live motion capture was used to record landing kinematic and kinetic data. Results of this study showed a significant increase in ankle eversion and external rotation angles for center leaps from pre- to postfatigue protocol (P =.020 and P =.020, respectively) as well as significant increases in ankle eversion and knee adduction moments for center leaps (P =.020 and P =.036, respectively). These results show that after a fatigue protocol, there are changes to the kinematics of dancers that may make them more susceptible to ankle injury. [ABSTRACT FROM AUTHOR]

Purpose: This pilot study investigated the functional outcomes after ischemic preconditioning (IPC) in high-level para-athletes with spinal-cord injury. Methods: Nine athletes completed 2 handgrip exercise trials (an isometric hold to failure at 60% maximal voluntary contraction [ISO] and a progressive, intermittent handgrip to failure [INT]), preceded by either IPC (220 mm Hg) or sham (20 mm Hg) for six 5-minute periods, in a repeated-measures, crossover design. Results: Although small performance improvements in time to task failure were observed in the ISO (∼5%) and INT (∼8%) IPC conditions, which are similar to those reported elsewhere, no statistical influence was observed (ISO–IPC, 74.2 [32.6] s; SHAM, 70.7 [27.2] s; P =.73; INT–IPC, 426.0 [80.1] s; SHAM, 392.2 [42.5] s; P =.35). Fatigue was evident in the forearm muscle force (maximal voluntary contraction) ISO (mean decline of 178.1 [76.0] N [95% CI, −10.4 to 366.7 N]; P <.05) and INT (mean decline of 182.2 [72.5] N [95% CI, 34.5–329.8 N]; P <.05) trials but not different between treatments (P >.95). Conclusions: Although small performance improvements in time to task failure were observed, the findings of the present data set suggest that acute bouts of IPC do not meaningfully influence fatigue during handgrip exercise in para-athletes with spinal-cord injury. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to assess the effect of playing different pick-and-roll (PnR) defensive tactical options during small-sided games (SSGs) on external and internal loads in female basketball players. Methods: Twelve female basketball players (age 28 [2] y; stature 175 [6] cm; body mass 65 [7] kg; playing experience 18 [4] y) belonging to a team competing in the Lithuanian second division were recruited for this study. Across 3 experimental sessions and in a randomized order, players performed 3 SSGs sharing the same features but using 3 defensive strategies on the middle PnR action: Switch, Trap, and Drop. External load was measured using PlayerLoad (PL); the number of accelerations, decelerations, and changes of direction, classified based on their intensities as low (<2.5 m·s−2), medium (2.5–3.5 m·s−2), and high (>3.5 m·s−2); and jumps categorized as low (<40 cm) and high (≥40 cm). Internal load was measured via rating of perceived exertion (RPE). Results: Higher PL values in SSGs including Trap defense were found compared with Drop (P <.001, ES = 0.69, moderate) and Switch (P =.001, ES = 0.60, moderate). Additionally, a higher number of accelerations was registered in Trap defense compared with Drop defense (P =.027, ES = 0.99, moderate). Trap defense also led to higher RPE compared with Switch (P =.003, ES = 1.49, large) and Drop (P =.004, ES = 1.42, large) defense. Conclusions: Different defensive strategies on the middle PnR can influence the external and internal loads during SSGs, and female basketball coaches should consider the high demand of the Trap defense when designing SSGs. [ABSTRACT FROM AUTHOR]

Context: The quadriceps femoris is consistently ranked among the muscles most prone to sustain strain injuries in sports involving kicking and sprinting actions. Given the documented preventive effect of Nordic hamstring curl programs against hamstring strain injuries, incorporating exercises that induce eccentric overload on the quadriceps could potentially help mitigate strain injuries within this muscle group. The Reverse Nordic Curl (RNC) has emerged as a viable field-based exercise for eccentrically working the quadriceps. This study aimed to compare quadriceps muscle eccentric activation during the RNC with 3 bodyweight squat-based exercises: single-leg squat (SLS), Bulgarian squat, and forward lunge. Design: Cross-sectional study. Methods: Twenty-three healthy volunteers (15 men) were monitored for rectus femoris, vastus lateralis, and vastus medialis electromyographic signal, as well as knee range of motion, while performing 10 repetitions of each exercise. Electromyography data acquired during eccentric phases were normalized by maximum voluntary isometric contraction of the knee extensors. The exercises were compared based on the electromyography and knee range of motion values. Results: RNC generated a similar rectus femoris and vastus medialis eccentric activation compared with the squat-based exercises (P >.05 for all), and a lower vastus lateralis activation than SLS (P <.001). Among the bodyweight squat-based exercises, SLS generated greater eccentric activation than forward lunge and Bulgarian squat for the 3 muscles (P <.05 for all). RNC was performed with lower knee-flexion range of motion than bodyweight squat-based exercises (P <.001). Conclusions: RNC did not produce superior eccentric quadriceps activation compared to bodyweight squat-based exercises, even proving to be less demanding for the vastus lateralis compared to the SLS. These findings may assist practitioners in selecting exercises to elicit quadriceps eccentric stimulus, with a focus on preventing strain injuries. [ABSTRACT FROM AUTHOR]

Background: The benefits of oral caffeine intake to enhance several aspects of physical performance, such as aerobic endurance, strength, power, and muscle endurance performance, are well supported. However, how the physical performance benefits of caffeine supplementation are translated into better specific actions in intermittent sports during real or simulated competition has been the topic of fewer investigations, and their results need to be appropriately reviewed and meta-analyzed. Objective: The aim of the study was to investigate the effects of acute caffeine intake on specific actions in intermittent sports involving decision making and high-intensity efforts (eg, team, racket, and combat sports) during real or simulated competitions. Methods: All studies included had blinded and crossover experimental designs, and we conducted a risk-of-bias analysis. In total, we included 24 studies. A meta-analysis was performed using the random-effects model to calculate the standardized mean difference (SMD) estimated by Hedges g and 95% CIs. Results: Caffeine ingestion increased high-intensity sport-specific actions during competition, such as the number of sprints (SMD: 0.48; 95% CI, 0.23–0.74), body impacts (SMD: 0.28; 95% CI, 0.08–0.49), accelerations (SMD: 0.35; 95% CI, 0.06–0.63), decelerations (SMD: 0.63; 95% CI, 0.12–1.14), and high-intensity offensive efforts (SMD: 0.36; 95% CI, 0.11–0.61). Additionally, caffeine ingestion induced a higher positive or success rate of actions during real or simulated competition (SMD: 0.44; 95% CI, 0.19–0.69). Conclusion: The current meta-analysis provides evidence of caffeine supplementation in increasing high-intensity efforts and the success rate of sport-specific actions during real or simulated competition. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the effects of acute ischemic preconditioning (IPC) on tennis skill and physical exercise performance, as well as to explore whether 7-day repeated IPC (RIPC) accelerated fatigue recovery after a simulated tennis match. Methods: Twenty-nine male tennis-specific current students were randomly allocated into 1 of 2 groups: SHAM (n = 14, 3 × 5 min at 20 mm Hg) and IPC (n = 15, 3 × 5 min at 220 mm Hg). Participants in both groups engaged in acute IPC and RIPC interventions. After the first acute IPC intervention, assessments were conducted to evaluate tennis-specific skills and overall physical exercise capacity. Following completion of chronic RIPC interventions, all participants competed in a simulated tennis match specifically designed to induce fatigue. To evaluate recovery from this induced fatigue, physical exercise capacity tests were conducted at 24 and 48 hours postmatch, allowing for an assessment of the participants' recovery capabilities over time. Results: After the first acute intervention, notable differences were observed between the IPC and SHAM groups in their performance on the repeated-sprint ability test. Specifically, the total times recorded were significantly shorter in the IPC group compared with the SHAM group (IPC: 109.05 [2.70] vs SHAM: 114.57 [7.45] s, P =.012), and this trend was also reflected in their best times (IPC: 4.20 [0.18] s vs SHAM: 4.39 [0.30] s, P =.042), indicating an immediate benefit of the IPC intervention on sprint performance. After a 7-day RIPC intervention, significant changes were noted in the SHAM group's performance metrics postmatch. There was an increase (P <.001) in fatigue index from 22% (8%) to 30% (9%) during repeated-sprint ability test and a decrease in serve speed from 120.2 (17.5) to 106.7 (13.0) km/h (P =.002) and knee peek torque from 196.0 (49.0) to 162.7 (39) N (extension, 60°/s, P <.001) in the SHAM group 24 hours postmatch, relative to the IPC group. Moreover, compared with the SHAM group, the IPC group showed a lower rate of perceived exertion during the match (P <.001) and a decrease in visual analog scale score (P =.026) 24 hours postmatch, suggesting enhanced recovery and reduced perception of pain relative to the SHAM group. Conclusion: IPC could serve as a strategy to generate an ergogenic effect and recovery during training and competition. [ABSTRACT FROM AUTHOR]

Purpose: The popularity of fencing and intense sports competition has burdened adolescents with excessive training, harming their immature bodies. Traditional training methods fail to provide timely movement corrections and personalized plans, leading to ineffective exercises. This paper aims to use artificial intelligence technology to reduce ineffective exercises and alleviate the training burden. Methods: We propose an action recognition algorithm based on the characteristics of adolescent athletes. This algorithm uses multimodal input data to comprehensively extract action information. Each modality is processed by the same network structure, utilizing attention mechanisms and adaptive graph structures. A multibranch feature fusion method is used to determine the final action category. Results: We gathered the fencing footwork data set 2.0. Our model achieved 93.3% accuracy, with the highest precision at 95.8% and the highest F1-Score at 94.5% across all categories. It effectively recognized actions of adolescents with different heights and speeds, outperforming traditional methods. Conclusion: Our artificial intelligence-based training solution improves training efficiency and reduces the training burden on adolescents. [ABSTRACT FROM AUTHOR]

Purpose: To determine the acute response of lactate supplementation on athletic performance. Method: Fifteen athletes under the age of 15 performed the following 4 sessions in a nonrandomized order: (1) familiarization, (2) control, (3) participants ingested calcium lactate (21.5 mg·kg−1 body mass), and (4) participants ingested a placebo (PLA, calcium carbonate, 21.5 mg·kg−1 body mass). The capsules were randomly offered and consumed 60 minutes before the physical tests. To assess the physical performance, the athletes executed squat jump, countermovement squat jump, 20-m linear sprint, change of direction test, and running anaerobic sprint test. Results: There were no significant differences between conditions for squat jump, countermovement jump, change of direction, and minimum power obtained in the running anaerobic sprint test (P >.05). Conversely, we observed a worse performance (P <.05) in the 20-m linear sprint test in the PLA and lactate conditions compared with control (P <.05). The lactate condition worsened performance during running anaerobic sprint test for peak power, mean power, and fatigue index compared with control and PLA (P <.05). Conclusions: Calcium lactate supplementation worsened repetitive running sprint ability and 20-m sprint performance. However, lactate supplementation does not affect jump or agility capacity. Therefore, calcium lactate supplementation seems to be an ineffective strategy to improve anaerobic and neuromuscular performance in soccer players 15 years of age or less. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to explore the interday reliability of mechanical variables obtained from the horizontal and vertical force–velocity (FV) profiles in adolescent female basketball players. If found to be reliable, the associations between FV parameters (theoretical maximal force, velocity, and power), squat jump (SJ) height, 30-m sprint, and change of direction (COD) times were evaluated. Methods: After familiarization, SJ against incremental loads, 30-m sprint, and 505-COD tests were obtained twice in 36 adolescent female basketball players (age = 15.4 [1.2] y). Results: Reliability for vertical FV parameters was unacceptable, whereas 505-COD times and FV horizontal parameters (except for theoretical maximal power) showed a moderate to high reliability. 505-COD time was correlated with FV horizontal parameters (range: r = −.821, −.451), and a large association was observed with both SJ height (r = −.678, −.600) and 30-m sprint time (r =.813,.858). Conclusions: Due to low levels of strength, our athletes were not adequately prepared to obtain a reliable vertical FV profile. Practitioners can expect acceptable reliability of the horizontal FV profile. Given the association between COD performance and SJ height and 30-m sprint time, we encouraged practitioners with limited equipment at their disposal to use COD and/or 30-m sprint tests. [ABSTRACT FROM AUTHOR]

The journey of Brazilian female Paralympians transcends mere statistical increases in women's participation. Behind the modest athlete growth lies the reality of women who are doubly marginalized by the intersection of gender and disability in an arena tailored for able-bodied men. Our study aimed to catalyze critical discourses surrounding the historical trajectory of Paralympic women's sports. Through a comprehensive documentary analysis based on the Brazilian Paralympic Committee's official documents from 1976 to 2021, we sought to shed light on this complex scenario. Numerically, Brazil's representation comprised 229 women who, predominantly, had physical impairments and engaged in individual sports. In addition to a sporting legacy deeply entrenched in physical rehabilitation with limited opportunities for team-based sports, we observed negative influences stemming from ableist and sexist narratives. A thorough investigation into Paralympic milestones revealed a multitude of social barriers and highlighted the significant impact of societal changes in reshaping athletic opportunities and challenging traditional stereotypes. [ABSTRACT FROM AUTHOR]

Background: We aimed to evaluate the effectiveness of the combination of protein supplementation and resistance training (RT), compared with RT alone or combined with a placebo, in improving gait speed. Methods: We searched PubMed, Web of Science, Cochrane Library, and SPORTDiscus databases, and 18 randomized controlled trials with 1,147 older participants were included for meta-analysis. Data were pooled as the effect sizes (Hedges' g) with 95% confidence interval (CI) of the gait speed (in meters per second). The random-effect meta-analysis, subgroup analyses, meta-regression, and sensitivity analysis were conducted. Results: The combination of protein supplementation and RT significantly improved gait speed (Hedges' g: 0.52 m/s, 95% confidence interval [0.17, 0.86], p =.005; I2 = 86.5%) compared with the RT alone. The subgroup analyses revealed that the significant improvement in gait speed postprotein intervention plus RT was observed only in participants who consumed protein after RT (Hedges' g: 0.90 m/s, 95% confidence interval [0.46, 1.33], p =.001; I2 = 79.6%). The pooled result did not significantly change after excluding any single study at one time or excluding smaller studies with large effect sizes. Conclusions: Protein supplementation combined with RT could significantly improve the gait speed of older adults compared with RT alone. This positive effect is more pronounced in people who consume protein after RT. [ABSTRACT FROM AUTHOR]

This systematic review aimed to evaluate the effects of aquatic exercise on physical performance in older adults. Databases were searched up to July 2021. Randomized controlled trials were screened by two reviewers, who extracted data and assessed study quality. Ten randomized controlled trials (603 participants) were included. Compared with nonexercising controls, aquatic exercise probably improved lower limb muscle power (30-s Chair Stand Test; mean difference 4.75 repetitions; 95% confidence interval [0.07, 9.42]; I2 = 99%; 251 participants; very low-quality evidence). When comparing aquatic exercise with land exercise, there is probably no superiority in favor of either intervention on dynamic balance (Timed Up and Go Test; mean difference −0.12 s; 95% confidence interval [−0.37, 0.12]; I2 = 3%; 244 participants; very low-quality evidence). [ABSTRACT FROM AUTHOR]

Little is known about physical activity (PA) and sedentary behavior (SB) among nursing home residents although PA is known as a health promoter. This study examined PA, SB, and their predictors among nursing home residents (n = 63). Dependent variables were accelerometry-based PA and SB. Predictor variables included in a path analysis were age, sex, body mass index, Barthel Index, cognitive status (Mini-Mental State Examination), physical performance (hand grip strength and habitual walking speed), and well-being (World Health Organization-5 well-being index). PA was very low (M steps per day = 2,433) and SB was high (M percentage of sedentary time = 89.4%). PA was significantly predicted by age (β = −0.27, p =.008), body mass index (β = −0.29, p =.002), Barthel Index (β = 0.24, p =.040), and hand grip strength (β = 0.30, p =.048). SB was significantly predicted by body mass index (β = 0.27, p =.008) and Barthel Index (β = −0.30, p =.012). Results might be helpful for everyday practice to identify individuals at high risk for low PA and high SB. [ABSTRACT FROM AUTHOR]

Purpose: Maximal speed is an important physical-fitness attribute for female Australian footballers. The effects of sprint training, maximal strength, and technical training have been reported in laboratory studies. However, no study has determined the combined effect and relative contribution of these training modalities on maximal speed adaptation in situ. Therefore, the aim of this study was to determine the training factors affecting maximal speed adaptation during a preseason in subelite female Australian Rules footballers. Methods: Maximal speed during field training, predicted 1-repetition maximum (1RM) for box squat and hip thrust, and sprint biomechanics were assessed during early and late preseason (∼9 wk apart) in 15 female subelite Australian Rules Football players (age 20 [3] y). On-field training volume and intensity (total distance, high-speed running, very-high-speed running, and maximal speed) were determined using a Global Positioning System. A multivariate regression model was used to determine the factors associated with changes in maximal speed across the preseason. Results: The preseason training program had a small effect on maximal speed and large to very large effects on strength and sprint biomechanics. The multivariate regression with the greatest fit (P <.001, R2 =.939) included change in estimated 1RM box squat (β = −0.63), total distance per week (β = −0.55), and change in hip projection (β = 0.16) as factors. Multivariate regression of biomechanical factors (P =.044, R2 =.717) and maximal strength factors (P =.003, R2 =.676) were also significant. Conclusion: The development of maximal speed across a preseason is dependent on (1) total distance per week, (2) maximal strength adaptation, and (3) sprint technique adaptation in female subelite Australian rules football players. [ABSTRACT FROM AUTHOR]

Purpose: Prediction of athlete wellness is difficult—or, many sports-medicine practitioners and scientists would argue, impossible. Instead, one settles for correlational relationships of variables gathered at fixed moments in time. The issue may be an inherent mismatch between usual methods of data collection and analysis and the complex nature of the variables governing athlete wellness. Variables such as external load, stress, muscle soreness, and sleep quality may affect each other and wellness in a dynamic, nonlinear, way over time. In such an environment, traditional data-collection methods and statistics will fail to capture causal effects. If we are to move this area of sport science forward, a different approach is required. Methods: We analyzed data from 2 different soccer teams that showed no significance between player load and wellness or among individual measures of wellness. Our analysis used methods of attractor reconstruction to examine possible causal relationships between GPS/accelerometer-measured external training load and wellness variables. Results: Our analysis showed that player self-rated stress, a component of wellness, seems a fundamental driving variable. The influence of stress is so great that stress can predict other components of athlete wellness, and, in turn, self-rated stress can be predicted by observing a player's load data. Conclusion: We demonstrate the ability of nonlinear methods to identify interactions between and among variables to predict future athlete stress. These relationships are indicative of the causal relationships playing out in athlete wellness over the course of a soccer season. [ABSTRACT FROM AUTHOR]

The literature describing the effects of mental fatigue (MF) has grown tremendously. This is accompanied by identification of a host of performance-determining parameters affected by MF. MF results from prolonged cognitive effort and predominantly affects physical, technical, tactical, and perceptual–cognitive dimensions of sport, while physiological parameters (eg, heart rate, lactate) and physical aspects of maximal and supramaximal efforts are predominantly unaffected. The aim of this paper was to provide an overview of the parameters described in the literature as influenced by MF. By identifying the different parameters, we not only see how they affect the performance of athletes but also raise concerns about the potentially increased injury risk due to MF. Preliminary evidence suggests that subsequent disturbances in balance, motor skills, and decision-making processes could potentially increase the vulnerability to injury. An abundance of lab-based studies looked into the effects of MF on performance; however, many questions remain about the mechanisms of origin and neurophysiological causes of MF, and only small steps have been taken to translate this knowledge into practice. Thus, there is a need for more research into the underlying mechanisms of MF and the role of the brain, as well as more applied research with a high ecological validity that also takes into account the potential increased risk of injury due to MF. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effects of 6-week barbell weighted-jump-squat (WJS) training with and without eccentric load reduction on explosive performance. Methods: Twenty well-trained male athletes were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). Participants completed 12 WJS training sessions (6 sets of 5 repetitions of barbell back squat at 30% of 1-repetition maximum [1RM]) twice a week over a 6-week period. While the control group used 0% eccentric loading (ie, traditional WJS), the experimental group utilized a 50% eccentric loading reduction with a mechanical braking unit (ie, eccentric load set at 15% of 1RM). Performance assessments, including countermovement jump, 20-m sprint, standing long jump, and 1RM barbell back squat, were conducted both before (pretests) and after (posttests) the intervention. Results: Both the experimental group and the control group demonstrated a significant increase in countermovement-jump height (+6.4% [4.0%] vs +4.9% [5.7%]; P <.001) and peak power output (+2.3% [2.7%] vs +1.9% [5.1%]; P =.017), faster 20-m sprint times (+9.4% [4.8%] vs +9.2% [5.5%]; P <.001), longer standing long jump (+3.1% [2.5%] vs +3.0% [3.3%]; P <.001), and higher 1RM back squat (+6.4% [4.0%] vs +4.9% [5.7%]; P <.001) from pretests to posttests. However, there was no significant condition × time interaction for any variable (all P ≥.294). Conclusions: Both WJS training methods, with and without load reduction in the eccentric phase, effectively enhance explosive performance. Nevertheless, athletes in later stages of injury rehabilitation or intense training may find reducing eccentric load a more tolerable strategy for achieving similar performance gains compared with traditional isoinertial loading. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of transcranial direct-current stimulation (tDCS) applied over the primary motor cortex (M1) and cerebellum on balance control and shooting accuracy in elite ice hockey players. Methods: Twenty-one elite ice hockey players underwent anodal tDCS over the M1 (a-tDCSM1), anodal tDCS over the cerebellum (a-tDCSCB), concurrent dual-site anodal tDCS over the M1 and the cerebellum (a-tDCSM1+CB), and sham stimulation (tDCSSHAM). Before and after receiving tDCS (2 mA for 15 min), participants completed an ice hockey shooting-accuracy test, Pro-Kin balance test (includes stance test and proprioceptive assessment), and Y-balance test in randomized order. Results: For static balance performance, the ellipse area in the 2-legged stance with eyes open and the 1-legged stance with the dominant leg significantly improved following a-tDCSM1, a-tDCSCB, and concurrent dual-site a-tDCSM1+CB, compared with tDCSSHAM (all P <.05, Cohen d = 0.64–1.06). In dynamic balance performance, the average trace error of the proprioceptive assessment and the composite score of the Y-balance test with the dominant leg significantly improved following a-tDCSM1 and concurrent dual-site a-tDCSM1+CB (all P <.05, Cohen d = 0.77–1.00). For the ice hockey shooting-accuracy test, shooting-accuracy while standing on the unstable platform significantly increased following a-tDCSM1 (P =.010, Cohen d = 0.81) and a-tDCSCB (P =.010, Cohen d = 0.92) compared with tDCSSHAM. Conclusion: tDCS could potentially be a valuable tool in enhancing static and dynamic balance and shooting accuracy on unstable platforms in elite ice hockey players. [ABSTRACT FROM AUTHOR]

Purpose: Travel fatigue impacts cognitive and physiologic systems, but its association with elite soccer match performance is unclear. In this retrospective observational study, we aimed to explore the association between travel and match outcomes in elite North American soccer. Methods: Travel data and match outcomes (team points or goals scored and conceded) and physical performance outcomes from 26 elite professional soccer teams and their players were analyzed (148 matches [team-based data] and 1252 player matches from 297 players; age 22.7 [4.5] y). Player- and match-level correlations between performance measures and both acute and cumulated travel metrics were analyzed. Results: Cumulative travel metrics were positively associated with team (travel distance [r =.20; 95% CI,.03–.25], travel time [r =.20;.06–.37], and time away [r =.20;.06–.37]) and individual player (travel distance, [r =.14;.08–.19], travel time [r =.17–.23], and time away [r =.13;.07–.18]) high-intensity running. Cumulative time away was negatively associated with team points (r = −.14; −.28 to −.001) and positively associated with goals conceded (r =.14;.01–.27); no clear association between acute travel metrics and match outcomes or physical performance was observed. Conclusions: As travel cumulated, away teams and their players ran more but for less reward (team points), although the magnitude of these associations was small. These data are exploratory and do not imply a causal relationship; however, further research should consider cumulation of travel. [ABSTRACT FROM AUTHOR]

Context: Horizontal hops can provide insight into how athletes can tolerate high-intensity single-leg stretch loads and are commonly used in athlete monitoring and injury management. Variables like flight, contact, and total time provide valuable diagnostic information to sports science professionals. However, gold-standard assessment tools (eg, 3-dimensional motion capture, force plates) require monetary and technological resources. Therefore, we used a tablet and free software to determine the between-rater, within-rater, and test–retest variability of the temporal events of multiple horizontal hop tests. Design: Reliability study. Methods: Nine healthy males (20.8 [1.3] y, 71.4 [9.8] kg, 171.7 [4.5] cm) across various university sports teams and clubs volunteered and performed several triple (3-Hop) and quintuple (5-Hop) horizontal hops over 3 testing sessions. Six raters detected temporal events from video to determine between-rater variability, while a single rater quantified within-session and test–retest variability. The temporal variables of flight time, ground contact time for each individual hop, and the total time of each hoping series were determined. The consistency of measures was interpreted using the coefficient of variation and interclass correlation coefficients (ICC). Results: Good to excellent between-rater consistency was observed for all hops (ICC =.85–1.00). Absolute (coefficient of variation ≤ 2.0%) and relative consistency (ICC =.98–1.00) was excellent. Test–retest variability showed acceptable levels of absolute consistency (coefficient of variation ≤ 8.7%) and good to excellent consistency in 10/16 variables (ICC =.81–.93), especially those later in the hopping cycle. Conclusions: A tablet and free digitizing software are reliable in detecting temporal events during multiple horizontal hops, which could have exciting implications for power diagnostics and return-to-play decisions. Therefore, rehabilitation and performance professionals can confidently utilize the highly accessible equipment from this study to track multiple hop performances. [ABSTRACT FROM AUTHOR]

Context: Analyzing flick movement kinematics biomechanically is important to prevent sport-related injuries in underwater hockey players since the aquatic-based flick movement is completely different from land-based flick movements. The study aimed to describe the flick movement kinematic biomechanically in underwater hockey players. Moreover, this study further aimed to investigate the effect of the Thrower's Ten exercises on flick movement kinematics in underwater hockey players. Design: Descriptive laboratory study. Methods: Seventeen underwater hockey players (age: 26.2 [4.3] y; sports age: 6.2 [4.5] y) were included. First, 2 underwater cameras using motion capture video analysis MATLAB were used to biomechanically analyze the angular changes on the shoulder, elbow, wrist, and body while players were performing the flick movements. Players were then recruited to the Thrower's Ten exercise program for 6 weeks. Flick movement kinematics and flick-throwing distance were recorded at baseline and 6 weeks. Results: The flick movement kinematic patterns demonstrated increased shoulder flexion (from 102.5° to 144.9°), wrist extension (from 9.5° to 10.8°), and upper-extremity rotation (from 5.7° to 56.8°) while decreased elbow extension (from 107.7° to 159.2°) from the stick met the puck until the competition of the movement. The Thrower's Ten exercises improved the elbow extension (P =.04), wrist extension (P =.01), body rotation (P <.001), and flick-throwing distance (P <.001) from baseline to 6 weeks. Conclusion: This study describes the underwater flick kinematic technique biomechanically and interprets preliminary findings for the first time. Thus, 6 weeks of Thrower's Ten exercise program provides more body muscle movements than the smaller ones during the flick movements and higher flick-throwing distance in underwater hockey players. [ABSTRACT FROM AUTHOR]