Search Results (1,511)

Background: Sleep is a key determinant of recovery and performance in elite athletes, yet its optimization extends beyond sleep duration alone and encompasses multiple subjective and physiological dimensions. Environmental factors, including the sleep surface, represent modifiable components of sleep that may influence perceived sleep quality. This study aimed to examine whether an individually adjustable modular sleep system improves subjective sleep quality in elite athletes and whether alterations in objective sleep metrics, circadian timing, or nocturnal autonomic physiology accompany such changes. Methods: Forty-three elite athletes participated in this pre–post-intervention study (without a control group). Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), while objective sleep and physiological parameters were recorded using a wearable device (Oura Ring, 3rd generation). Outcomes were averaged across three consecutive nights at baseline (T0) and post-intervention (T1). Baseline values were derived from the final three nights of a standardized pre-intervention monitoring period (minimum 7 nights), and post-intervention values from the final three nights following a standardized intervention exposure period (minimum 14 nights). Statistical analyses included paired frequentist tests and complementary Bayesian paired-sample analyses. Results: Subjective sleep quality improved significantly following the intervention, with a mean reduction in PSQI score of 0.67 points (p < 0.001). In contrast, no meaningful changes were observed in total sleep time (p = 0.28), REM duration (p = 0.26), circadian timing (p = 0.47), or nocturnal minimum heart rate (p = 0.42), as supported by the absence of physiological changes in these parameters. Conclusions: It seems that an individually adjustable sleep system can be able to improve perceived sleep quality in elite athletes without disrupting sleep architecture, circadian regulation, or nocturnal autonomic function. In athletes whose sleep duration and physiological sleep metrics are already near optimal, such micro-environmental interventions may offer a feasible, low-risk means of enhancing recovery by targeting subjective sleep quality. This dimension dissociates from objective sleep measures. Optimizing the sleep surface may therefore represent a practical adjunct to existing recovery strategies in high-performance sport. Full article

Background/Objectives: Energy availability (EA), defined as the dietary energy remaining after exercise energy expenditure (EEE), is a central determinant of both health and performance in athletes. Chronic insufficient EA leads to low energy availability (LEA), which is an underlying mechanism of Relative Energy Deficiency in Sport (REDs). This narrative review critically explores the conceptual evolution of EA and LEA, summarizes current physiological evidence, and discusses methodological and practical challenges in their assessment and application in free-living athletes. Methods: Evidence from experimental and observational studies was reviewed to describe the hormonal, metabolic, and performance outcomes associated with LEA. Screening tools, including the Low Energy Availability in Females Questionnaire (LEAF-Q) and the Low Energy Availability in Males Questionnaire (LEAM-Q), were also evaluated for their validity and applicability in different sports contexts. Results: LEA is associated with alterations in thyroid and reproductive hormones, which, in turn, contribute to reduced resting metabolic rate, lower bone mineral density, and delayed recovery. While screening questionnaires can help identify athletes at risk, their accuracy varies by sport and individual characteristics. Incorporating hormonal and metabolic biomarkers provides a more direct and sensitive method for detecting physiological stress. Measuring dietary intake, EEE, endocrine balance and body composition in real-world settings remains a major methodological challenge. Combining hormonal, metabolic, and behavioral indicators may improve the identification of athletes experiencing LEA. Conclusions: EA plays a central role in the interaction between nutrition, exercise, and athlete health, but methodological limitations in its assessment may compromise accurate diagnosis. Improving measurement techniques and adopting integrated monitoring strategies are essential to improve early detection, guide individualized nutrition, and prevent RED-related health and performance impairments. Full article

Background/Objectives: Optical coherence tomography angiography (OCTA) is a non-invasive imaging method that enables accurate in vivo visualisation and quantification of the macular and optic nerve head microvasculature, providing an indirect assessment of local retinal perfusion. This study aimed to evaluate the changes in OCTA perfusion parameters of macula and optic nerve head in healthy individuals following different isometric exercises and to determine their association with intraocular pressure alterations. Methods: Each subject performed four isometric exercises: elbow plank, reverse plank, right-side plank, and wall sit. Measurements of intraocular pressure, systemic blood pressure, heart rate, and OCT angiography of macula and optic nerve head were conducted before each exercise, immediately after its completion, and after a five-minute rest period. Intraocular pressure was measured using a Perkins applanation tonometer, and systemic blood pressure and heart rate were recorded using an automated sphygmomanometer. The relationship between changes in intraocular pressure and OCTA perfusion parameters was analysed. Results: A total of 12 eyes of 12 healthy subjects were included in the study, with a mean age of 28.67 ± 2.39 years. An immediate reduction in optic nerve head vessel density was observed after each exercise (elbow plank: p = 0.012; wall sit: p = 0.009; reverse plank: p < 0.001; right-side plank: p < 0.001), with a sustained decrease during the rest period following right-side plank. No significant changes in vessel density were observed in the macular region. Heart rate and systemic blood pressure increased after each exercise, while intraocular pressure increased following all exercises except the wall sit. Changes in intraocular pressure were significantly negatively associated with changes in optic nerve head vessel density in the post-rest period following elbow plank (inside disc sector: b = −1.153, p = 0.02, peripapillary sector: b = −0.369, p = 0.009) and reverse plank (whole image sector: b = −0.589, p = 0.031). Conclusions: The performance of isometric exercises induced an acute reduction in optic nerve head vessel density, and a significant association with intraocular pressure changes was observed. OCTA represents a promising research tool not only for the assessment of retinal microcirculation but also in the field of sports medicine. Full article

This study investigated the effects of 6 weeks of plyometric training (PT) performed on soft (unstable) and hard (stable) surfaces compared with conventional training on the balance, explosive power, and muscle strength of adolescent female basketball players. The participants were randomly assigned to three groups: soft-surface PT (n = 14), hard-surface PT (n = 14), and conventional training (n = 14). Performance outcomes included 30 m sprint time, vertical jump height, plantar flexion and dorsiflexion maximal voluntary isometric contraction (MVIC) torque, Y-balance dynamic balance, and center of pressure-based static balance. Ground reaction forces, MVIC torques, and balance parameters were measured using high-precision force sensors to ensure accurate quantification of biomechanical performance. Statistical analyses were performed using two-way repeated-measures ANOVA with post hoc comparisons to evaluate group × time interaction effects across all outcome variables. Results demonstrated that soft- and hard-surface PT significantly improved sprint performance, vertical jump height, and plantar flexion MVIC torque compared with conventional training, while dorsiflexion MVIC increased similarly across all the groups. Notably, soft-surface training elicited greater enhancements in vertical jump height, dynamic balance (posteromedial and posterolateral directions), and static balance under single- and double-leg eyes-closed conditions. The findings suggest that PT on an unstable surface provides unique advantages in optimizing neuromuscular control and postural stability beyond those achieved with stable-surface or conventional training. Thus, soft-surface PT may serve as an effective adjunct to traditional conditioning programs, enhancing sport-specific explosive power and balance. These results provide practical guidance for designing evidence-based and individualized training interventions to improve performance and reduce injury risk among adolescent female basketball athletes. Full article

Single-leg squats are commonly used to assess lower-limb strength and alignment; however, their application for evaluating postural control remains underexplored. This study assessed the reliability and agreement of postural control measures within and between unipedal squat variations. Twenty-eight physically active adults performed a conventional single-leg squat (CSLSQ), the anterior excursion of the Y-Balance Test (ANYBT), and a forward step-down (FRSTD) with both limbs on two occasions, 5–7 days apart. The mean values of five trials were analyzed for center-of-pressure (COP) 95% confidence ellipse area (95%CEA), path length (PL), velocity (VL), and mediolateral and anteroposterior variability (RMS-X and RMS-Y). Most COP variables demonstrated good-to-excellent reliability (ICC = 0.780–0.948), whereas RMS-X showed lower reliability (ICC = 0.367–0.803) and higher measurement error across limbs. The FRSTD demonstrated high ICCs (0.780–0.948) and low measurement error, comparable to the CSLSQ (0.794–0.940) and generally higher than the ANYBT (0.790–0.895), regardless of limb. Overall, the dominant limb exhibited higher ICCs and lower measurement error than the non-dominant limb. Inter-task agreement was greatest between the CSLSQ and FRSTD, primarily on the dominant limb, indicating greater potential interchangeability for selected COP metrics (95% CEA, VL, and RMS-Y). These findings may assist clinicians and sports scientists in selecting appropriate single-leg squat tasks and COP measures for assessment. Full article

Background: Reaction time and coordination are key performance components in team sports such as handball, particularly during the developmental years. Integrating visual and cognitive stimuli through smart technologies has been shown to facilitate motor skill development in young athletes. Methods: This study evaluated the effects of a BlazePod-based training protocol on reaction time, visuomotor coordination, movement quickness, and change-of-direction performance in junior male handball players aged 12–14 years. Thirty-two athletes (mean age = 13.37 ± 0.29 years) were randomly assigned to an experimental group (n = 16), in which the traditional neuromotor/coordination block of regular practice was replaced with BlazePod-based drills three times per week for eight weeks, or to a control group (n = 16), which trained the same capacities with traditional handball-specific exercises without technology. Training frequency (3 sessions/week), session duration (90 min), and the workload of the 30 min neuromotor block were matched between groups. Motor performance was assessed using four tests: Focus Reactions, Fast Feet, Clap Challenge, and the Agility T-Test. Paired- and independent-samples t-tests were applied to compare pre- and post-intervention scores. Results: The experimental group showed significant within-group improvements in Focus Reactions (p = 0.002) and AgilTT_ShuffleLeft (p = 0.014), whereas the control group showed no improvements and a small but significant worsening in Focus Reactions. Between-group comparisons at post-test revealed significant differences in favor of the experimental group for Fast Feet (p = 0.036), Clap Challenge (p = 0.008), AgilTT_Overall (p < 0.001), and AgilTT_SprintBack (p = 0.003). Conclusions: The integration of BlazePod technology into handball training produced measurable improvements in reaction speed and lateral agility among junior players. These findings suggest that technology-assisted neuromotor training represents a viable training modality that can replace a traditional neuromotor block within youth handball practice while maintaining overall training dose. Full article

Problem Statement: Upper crossed syndrome (UCS), as first described by Janda, refers to a group of muscle imbalances in which tightness in the upper trapezius and levator scapulae dorsally cross with tightness in the pectoralis major and minor muscles, and weakness of deep cervical flexors cross ventrally with weakness of the middle and lower trapezius. Postural alterations from this dysfunction, including forward head, rounded shoulders, and scapular dyskinesis, contribute to upper-back and shoulder pain, particularly among office workers who spend long periods of the workday on a computer. Upper crossed syndrome is a significant contributor to both neck pain and shoulder pain among computer users, which have been rated at 55–69%, and 15–52%, respectively. Despite its prevalence, knowledge about UCS and its treatment remains spotty among primary care physicians. In addition, improvements in workstation ergonomics along with hourly work breaks may be considered as primary prevention strategies for UCS. Objectives: This narrative review examines and synthesizes evidence about the epidemiology and diagnosis of UCS, along with clinical recommendations for physiotherapeutic approaches to treatment. Ergonomic measures in the workplace, including changes in the design of computer workstations so that both the keyboard and monitor are at the proper heights to minimize the risk of long-term musculoskeletal disorders, are also critical. Methods: The first author, a Doctor of Behavioral Health, performed the initial literature search, which was reviewed by the second author, a PhD in sports injury epidemiology. The third author, a chiropractor and practice owner, provided clinical recommendations for stretching and strengthening exercises, which were also described in the literature. Discussion: While easily treatable when caught early, UCS may become resistant to noninvasive approaches over time, and more severe pathologies of the neck and shoulder, including impingement, thoracic outlet syndrome, and cervicogenic headaches may result. Because there is no specific ICD code for UCS, it is important for physicians to recognize the early signs, consider them in the context of workplace-related injuries, and understand physiotherapeutic strategies for symptom resolution. Full article

Indoor bouldering is a popular and rapidly growing sport in which climbers fall repeatedly from walls up to 4–5 m high, making lower-limb injuries common. It is therefore essential to understand fall kinematics and impact conditions, yet fall kinematics remain poorly documented because laboratory motion capture is impractical in gyms. This study aimed to validate a markerless multi-camera pipeline (Pose2Sim) against a 2D video annotation tool (Kinovea) for displacement and velocity measurement, and against IMUs for peak acceleration. Ten teenage athletes (3 males, 7 females; 14–17 years) performed 40 falls recorded with five cameras (GoPro HERO12, USA, 2.7 K, 240 fps) and three IMUs (Blue Trident, Vicon, UK; ±200 g, 1600 Hz). Cut-off frequencies were set using Yu’s method (13 Hz for video, 39 Hz for IMUs). Pose2Sim’s results closely matched those of Kinovea for fall height and peak velocity with non-significant differences but underestimated peak acceleration. At the forehead, no significant difference was found, likely due to smaller accelerations at the head. Markerless video analysis is appropriate for studying fall kinematics and typology in indoor bouldering. IMUs remain necessary to quantify impact intensity, and future work should explore the combination of both IMUs and video to overcome this limitation. Full article

Introduction. Sleep is an essential component in the recovery, performance, and injury prevention processes of soccer players. Associated psychological variables, such as the balance between stress and recovery, have been less explored, despite their potential influence on rest and injury vulnerability. This study aims to examine the relationship between sleep quality, quantity, and chronotype and injury risk in soccer players, also incorporating the modulating role of stress and recovery. Method. A PRISMA systematic review was conducted using searches in ScienceDirect, PubMed, Ovid, EBSCO, MDPI, Springer Nature Link, SPORTDiscuss (full text), and Dialnet. Original studies and reviews on sleep and its relationship with sports injuries in soccer players or comparable athletic populations were included. Eighteen studies were selected that addressed sleep indicators (quality, quantity, chronotype), injury incidence, and, to a lesser extent, measures of stress and recovery using instruments such as the RESTQ-Sport or wellness questionnaires. Results. There is evidence of an association between poor sleep quality or quantity and an increased risk of injury or illness. Chronotype is an emerging variable of interest, although still insufficiently researched. Regarding stress and recovery, direct evidence is limited, although studies that address this issue show that an imbalance between these two dimensions negatively impacts sleep quality and increases susceptibility to injury. Conclusions: Sleep and the stress–recovery balance are key and interdependent factors in the risk of injury in soccer players. Future research should consider including these variables to further understand the mechanisms underlying the injury process and optimize prevention and recovery strategies. Full article

Background/Objectives: Caffeine is a well-established ergogenic aid in many strength- and endurance-based sports, but its efficacy in sport climbing remains underexplored despite the sport’s unique physical demands on grip strength, power, and muscular endurance. Therefore, this study examined the acute impact of a low caffeine dose (3 mg/kg) on climbing-specific performance, including pull-up and grip tests, in intermediate-advanced climbers. Methods: In a triple-blind, randomized, crossover design, thirteen male climbers (age: 28.2 ± 8.6 years) completed two experimental trials (caffeine vs. placebo). Performance was assessed via a pull-up one-repetition maximum (1RM) and power test at various loads, a pull-up muscular endurance test, and grip tests including maximum dead-hang time, maximum dead-hang strength, and rate of force development (RFD). Results: Caffeine did not significantly enhance performance in any measured variable. While a non-significant increase in peak power was observed at 80% 1RM (+8.0%, 95% CI: −0.232 to 0.304, p > 0.05, g = 0.348), effects at other loads and on pull-up endurance were trivial based on effect size (e.g., repetitions: +3.3%, 95% CI: −3.30 to 4.37, p = 0.292, g = 0.061). For grip metrics, caffeine was associated with a modest reduction in endurance time (+7.4%, p = 0.162, g = 0.171) and a slight increase in maximum strength (+2.4%, p = 0.060, g = 0.120). RFD was unaffected (p > 0.169, g < 0.13). Despite the lack of objective improvement, participants reported significantly greater subjective feelings of strength, energy, and alertness with caffeine (p < 0.05). Conclusions: A 3 mg/kg dose of caffeine, while altering psycho-physiological state, did not elicit statistically or practically meaningful ergogenic effects on pull-up or grip performance in climbers. Higher doses or sport-specific performance tests should be investigated in future research. Full article

Background: Adolescence is a sensitive period for psychological, academic, and social development, and sports participation has been described as a potential protective factor for academic performance and psychological well-being. However, limited research has examined the combined influence of sports involvement, sport type, and family background on adolescents’ academic and psychological outcomes. This study aimed to investigate the associations between organized sport participation, sport type (football vs. judo), psychological well-being, psychosomatic symptoms, academic performance, and family socioeconomic background among adolescent boys. Methods: The sample consisted of 52 boys aged 11–14 years from a rural school, divided into football players (n = 13), judo athletes (n = 13), non-athletes (n = 13), and a contextual subgroup of students with special educational needs (SEN; n = 13), with the latter included for exploratory purposes only. Data included school-record-based academic performance and validated self-report measures of life satisfaction, depressive symptoms, psychosomatic complaints, perceived physical fitness, and socioeconomic background. Results: Athletes demonstrated significantly higher academic achievement than non-athletes in overall grade point average (p < 0.001), mathematics (p < 0.001), Romanian (p < 0.001), English (p = 0.03), and Hungarian (p < 0.001). They also reported higher life satisfaction (p < 0.001) but simultaneously showed slightly elevated depressive symptom scores (p < 0.001), indicating a paradoxical pattern of concurrent psychosocial benefits and psychological strain. Parental education (p < 0.001), parental occupational status (p = 0.01), and fathers’ occupational position (p = 0.02) were significantly higher among athletes’ families. Perceived physical fitness was also rated higher by athletes (p < 0.001). No significant differences were found in body mass index, family structure, or most psychosomatic symptoms. Conclusions: Sport participation was associated with more favorable academic and psychological indicators, yet also with elevated depressive symptoms, highlighting the dual nature of organized sport during adolescence. Future research should apply longitudinal designs, include female participants, and incorporate objective indicators of training load. Full article

Background and Objectives: Asymmetries in body composition and movement patterns are common in professional basketball due to the sport’s repetitive and unilateral demands. While both structural and functional asymmetries have been independently studied, little is known about their interaction under real training conditions. The aim of this study was to compare structural asymmetries, obtained from bioelectrical impedance analysis, with functional asymmetries, measured through inertial devices in professional basketball players. Methods: Twenty-five male professional basketball players from two Spanish teams were monitored over a two-month period. Structural asymmetries were assessed via the TANITA MC-780MA multi-frequency analyzer, while functional asymmetries were quantified using WIMU Pro™ inertial units during 43 training sessions. Descriptive, correlational, and cluster analyses were performed, followed by linear mixed-effects models adjusted for individual random effects, with statistical significance set at p < 0.05. Results: Descriptive results revealed low overall fat mass and no relevant group-level asymmetries in muscle mass or functional variables, although fat mass asymmetry showed greater variability across players. Correlation analyses indicated weak and non-significant relationships between structural and functional asymmetries. Cluster analysis grouped muscle mass and functional asymmetries together, while fat mass asymmetry formed a distinct cluster. Linear mixed-effects models confirmed significant differences for muscle mass asymmetry and demonstrated high inter-individual variability. Conclusions: Structural and functional asymmetries behave independently, with muscle mass asymmetry showing greater variability and functional relevance. These findings highlight the need for individualized monitoring approaches integrating morphological and functional assessments to optimize performance and reduce injury risk in elite basketball players. Full article

Background/Objectives: The Achilles tendon is the largest tendon in the human body; it is frequently ruptured during sports and other dynamic physical activities. The purpose of this study was to compare recovery patterns over time between injuries to the dominant (DMT) and non-dominant (NDMT) limbs, and to examine differences in the limb symmetry index (LSI) for the uninjured side. Methods: This study includes a retrospective analysis of individuals who completed a standard rehabilitation program for 12 months and had regular checkups every three months. The study sample comprised 17 patients with DMT injuries and 17 patients with NDMT injuries, all active male recreational participants who underwent surgical repair of an Achilles tendon rupture. Outcome measures included dorsiflexion range of motion (ROM), calf circumference, plantarflexion strength, hop test performance, and the Y-Balance Test (YBT). Results: Both groups demonstrated continuous, progressive improvement in ROM, plantarflexion strength, hop test distance, and YBT scores, showing a significant main effect of time (p < 0.05). Although DMT showed greater strength than NDMT at 6 and 9 months, this difference was no longer significant at 12 months (p > 0.05). In all three YBT directions, the DMT group achieved greater reach distances than the NDMT group at 12 months (p < 0.05). At the final follow-up, both groups exceeded 90% LSI in ROM, calf circumference, plantarflexion strength, and hop performance (p < 0.05). However, in the YBT, only the DMT group surpassed 90% LSI, whereas the NDMT group showed poorer recovery. Conclusions: ROM, calf circumference, and muscle strength ultimately showed no significant differences between groups, but dynamic balance recovery was superior in the DMT group. These findings suggest that clinicians and rehabilitation specialists should consider leg dominance when designing rehabilitation programs. Full article

Background: Executive functions, notably attention and processing speed, are essential for athletic performance, especially in sports that require quick reactions and decision-making under pressure. The current study aims to assess the impact of the SmartACT program—a psychological intervention that includes acceptance and commitment therapy, hypnosis, and guided imagery—on attentional processes and psychological flexibility in adolescent student-athletes. Methods: This 7-week quasi-experimental controlled study investigated the efficacy of SmartACT in adolescent student-athletes aged 15 to 18. A total of 309 individuals were divided into three groups using convenience sampling: SmartACT (n = 93), MAC (Mindfulness–Acceptance–Commitment, the standardized Gardner & Moore technique; n = 109), and control (n = 107). The d2 test was used to examine attention and visual processing, while the Acceptance and Action Questionnaire—II (AAQ-II) was used to assess psychological flexibility, both before and after the intervention. The data were analyzed using mixed-design repeated-measures ANOVA and paired-samples t-tests. Results: The SmartACT group showed significant improvement on both tests, specifically in the total number of items processed in the d2 test (457.83 to 600.24; p < 0.001), and experiential avoidance, measured by AAQ-II, decreased (18.48 to 12.80; p < 0.001), indicating increased psychological flexibility. Conclusions: The main findings of our study suggest that integrating ACT with hypnosis and imagery may enhance cognitive attentional functions and psychological flexibility in adolescent student-athletes. Full article

Wearable inertial measurement units (IMUs) provide an accessible means of monitoring fatigue-related changes in running biomechanics, yet most existing methods rely on limited feature sets, lack personalization, or fail to generalize across individuals. This study introduces a bioinformatics-inspired stride sequence modeling framework that integrates spectral–entropy features, sample entropy, frequency-domain descriptors, and mixed-effects statistical modeling to detect fatigue using a single lumbar-mounted IMU. Nineteen recreational runners completed non-fatigued and fatigued 400 m runs, from which we extracted stride-level features and evaluated (1) population-level fatigue classification via global leave-one-participant-out (LOPO) models and (2) individualized fatigue detection through supervised participant-specific models and non-fatigued-only anomaly detection. Mixed-effects models revealed robust and multidimensional fatigue effects across key biomechanical features, with large standardized effect sizes (Cohen’s d up to 1.35) and substantial variance uniquely explained by fatigue (partial R² up to 0.31). Global LOPO machine learning models achieved modest accuracy (55%), highlighting strong inter-individual variability. In contrast, personalized supervised Random Forest classifiers achieved near-perfect performance (mean accuracy 97.7%; mean AUC 0.997), and NF-only One-Class SVMs detected fatigue as a deviation from individual baseline patterns (mean AUC 0.967). Entropy and stride-to-stride variability metrics further demonstrated consistent fatigue-linked increases in movement irregularity and reduced neuromuscular control. These findings show that IMU stride sequences contain highly informative, fatigue-sensitive biomechanical signatures, and that combining bioinformatics-inspired sequence analysis with hybrid statistical and personalized AI models enables both robust population-level insights and highly reliable individualized fatigue monitoring. The proposed framework supports future integration into sports analytics platforms, digital coaching systems, and real-time wearable fatigue detection technologies. This highlights the necessity of personalized fatigue-monitoring strategies in wearable systems. Full article