Search Results (24)

Background: Motion capture (MoCap) technologies have transformed athlete monitoring, yet athletic departments face complex decisions when selecting systems for multiple sports. Methods: We conducted a narrative review of peer-reviewed studies (2015–2025) examining optical marker-based, inertial measurement unit (IMU) systems, including Global Navigation Satellite System (GNSS)-integrated systems, and markerless computer vision systems. Studies were evaluated for validated accuracy metrics across indoor court, aquatic, and outdoor field environments. Results: Optical systems maintain sub-millimeter accuracy in controlled environments but face field limitations. IMU systems demonstrate an angular accuracy of 2–8° depending on movement complexity. Markerless systems show variable accuracy (sagittal: 3–15°, transverse: 3–57°). Environmental factors substantially impact system performance, with aquatic settings introducing an additional orientation error of 2° versus terrestrial applications. Outdoor environments challenge GNSS-based tracking (±0.3–3 m positional accuracy). Critical gaps include limited gender-specific validation and insufficient long-term reliability data. Conclusions: This review proposes a tiered implementation framework combining foundation-level team monitoring with specialized assessment tools. This evidence-based approach guides the selection of technology aligned with organizational priorities, sport-specific requirements, and resource constraints. Full article

Background: The prevalence of vitamin D deficiency has been a growing concern in recent years. Vitamin D is important in many of the body’s physiological systems, such as the musculoskeletal, cardiovascular and immune functions. A deficiency of vitamin D in athletes may negatively impact both muscle functions and recovery and, thus, affect performance and increase the risk of injury. Many studies assessed the prevalence of vitamin D deficiency in athletes; however, as of today, there are no official recommendations/protocols for screening vitamin D levels in athletes, and only a few studies were performed in male and female elite athletes (i.e., Olympic level), in different sport disciplines. Method: We investigated the prevalence of vitamin D deficiency among athletes entering the Israeli Olympic team. A total of 761 samples of Vitamin D(OH)25 from 334 athletes were analyzed. For this analysis, we used the first test the athlete had performed when joining the Olympic team. The prevalence of vitamin D deficiency (<50 nmol/L, as defined by the Endocrine Society Committee) was investigated according to gender, types of sports and outdoor vs. indoor sports through the different seasons of the Israeli Olympic team athletes. Result: Twenty-five athletes (7.5%) were diagnosed with vitamin D deficiency. One hundred and thirty-one athletes (39.2%) had insufficient levels of vitamin D (50–75 nmol/L). The highest incidence of vitamin D deficiency was found amongst gymnastics and combat sport athletes. A significant difference was also found in vitamin D concentration between seasons. Vitamin D average concentration in the winter was 74.1 nmol/L compared to 86.4 nmol/L in the Summer (p < 0.0005). Conclusions: Due to the importance of vitamin D to athletic performance and the high prevalence of deficiency and insufficiency, we suggest careful and frequent monitoring of groups at risk, including elite athletes, especially in susceptible sports and during the winter. Future studies are necessary to investigate the effectiveness of Vitamin D supplementation in athletes with low baseline vitamin D levels. Full article

Attention is an essential psychological component in sports games, which conditions sports success. The purpose of this study was to identify the attention style (internal or external) and the weight of attention qualities depending on the practiced team sport (basketball, volleyball, or handball) and gender (female or male), in athletes aged 15–18. A total of 177 active athletes (87 female (mean age ± standard deviation: 16.07 ± 0.94 years) and 90 male (mean age ± standard deviation: 15.96 ± 0.82 years)) were involved in the study, including 62 handball players (28 female and 34 male), 58 volleyball players (30 female and 28 male) and 57 basketball players (29 female and 28 male). In the study, two questionnaires were applied: one implemented to identify the attentive style with the two dimensions internal and external (standardized), called questionnaire for the assessment of attentional style in athletes (QASA), and one designed by us, called questionnaire to identify the weights of attention qualities according to the characteristics of the practiced sport (QAQCS), aiming to identify the most relevant quality of attention, depending on the practiced sport. Cronbach’s alpha for both questionnaires was between 0.701 and 0.855. The results recorded in the present study reveal a variation in the attentional style between the groups of athletes and between genders. The results of the study highlight that in handball, girls have a predominantly external style with a total of 10.213 points; in boys’ handball, the predominant focus of attention is internal with a total score of 9.087 points. Girls’ volleyball focus of attention is predominantly external, with 8.999 points; in boys’ volleyball, the attention style is internal, registering a score of 9.713 points. In girls’ basketball, the predominant focus of attention is internal, with a total score of 8.516 points; in boys’ basketball, the external attention style is predominant, with 9.213 points. Looking at the weight of attention qualities, it was found that the most relevant for girls is concentration and mobility for handball players, stability was identified in volleyball, and distributiveness in basketball. In boys’ handball teams, mobility is the most essential, just like in basketball, and in volleyball it was found that stability has the biggest impact. ANOVA analysis highlighted statistically significant differences between groups of sports games by gender category, at both subscales of (QASA), as well as QAQCS, p < 0.05. The results of our study highlight differences between the attentional styles and their qualities in relation to the gender and the specific sport played, which determines differentiated approaches to these psychological components. Full article

Background: Sweat and thermal responses in individuals with spinal cord injury (SCI) are impaired depending on lesion characteristics. This is particularly problematic for athletes and may ultimately lead to reduced performance. This exploratory study investigated the feasibility of field-usable methods to objectively collect data relevant to sweat response in elite athletes with SCI. Differences in sweat response were also evaluated for different athlete characteristics. Methods: Measurements were performed during exercise and included core temperature (Tc), heart rate, urine specific gravity, fluid intake, sweat rate, and sweat electrolyte concentration. Differences for sex, lesion level (tetraplegia versus paraplegia), motor impairment (complete versus incomplete), and sport type (endurance versus team/skill) were evaluated. Results: Fifteen athletes (median (Q1–Q3) age, 30 (28–36) years; three females; 11 with complete lesions) were included. Endurance athletes were measured during indoor performance tests (n = 10), whereas team/skill athletes were measured during training sessions (n = 5). In the mixed exercise intensities, the average Tc was 37.7 (37.3–37.8) °C and the average heart rate was 126 (100–146) bpm. Dehydration, defined as a urine specific gravity > 1.020 ng/mL, was prevalent in six athletes before exercise and in five athletes after exercise. The sweat rate was lower in athletes with tetraplegia (p = 0.02) and in team/skill athletes (p = 0.008). Conclusions: Collecting sweat and thermal response data from athletes with SCI in the field is feasible. Given the suboptimal hydration status of many athletes, raising awareness of the importance of hydration seems valuable. Full article

Sports centers are significant energy consumers. This article outlines the engineering design for a comprehensive energy performance upgrade of the indoor sports hall in Arkalochori, Greece, and presents the projected results. The indoor sports hall constitutes a major sport facility on the mainland of Crete, hosting a broad cluster of sport municipal activities and the official basketball games of the local team in the 2nd national category. Having been constructed in the mid-1990s, the facility exhibits very low thermal performance, with considerably high U-factors for all constructive elements (from 4 to 5 W/m²∙K), still use of diesel oil for indoor space heating and domestic heat water production, and ineffective old lamps and luminaries covering the lighting needs of the facility. The energy performance upgrade of the indoor sports hall was studied, and the following passive and active measures were considered: Opaque-surfaces’ thermal insulation and openings’ replacement, stone wool panels, installation of heat pumps for indoor space conditioning, removal of diesel oil for any end use, production of domestic hot water from a novel solar-combi system, upgrade of lighting equipment, installation of solar tubes on the main sports hall roof for natural lighting as well as of a photovoltaic system for covering the remaining electricity consumption. With the proposed interventions, the studied building becomes a zero-energy facility. The payback period of the investment was calculated at 26 years on the basis of the avoided energy cost. This work was funded by the “NESOI” Horizon 2020 project and received the public award “Islands Gamechanger” competition of the NESOI project and the Clean Energy for EU Islands initiative. Full article

The use of inertial devices in sport has become increasingly common. The aim of this study was to examine the validity and reliability of multiple devices for measuring jump height in volleyball. The search was carried out in four databases (PubMed, Scopus, Web of Sciences and SPORTDiscus) using keywords and Boolean operators. Twenty-one studies were selected that met the established selection criteria. The studies focused on determining the validity and reliability of IMUs (52.38%), on controlling and quantifying external load (28.57%) and on describing differences between playing positions (19.05%). Indoor volleyball was the modality in which IMUs have been used the most. The most evaluated population was elite, adult and senior athletes. The IMUs were used both in training and in competition, evaluating mainly the amount of jump, the height of the jumps and some biomechanical aspects. Criteria and good validity values for jump counting are established. The reliability of the devices and the evidence is contradictory. IMUs are devices used in volleyball to count and measure vertical displacements and/or compare these measurements with the playing position, training or to determine the external load of the athletes. It has good validity measures, although inter-measurement reliability needs to be improved. Further studies are suggested to position IMUs as measuring instruments to analyze jumping and sport performance of players and teams. Full article

This paper focuses on image and video content analysis of handball scenes and applying deep learning methods for detecting and tracking the players and recognizing their activities. Handball is a team sport of two teams played indoors with the ball with well-defined goals and rules. The game is dynamic, with fourteen players moving quickly throughout the field in different directions, changing positions and roles from defensive to offensive, and performing different techniques and actions. Such dynamic team sports present challenging and demanding scenarios for both the object detector and the tracking algorithms and other computer vision tasks, such as action recognition and localization, with much room for improvement of existing algorithms. The aim of the paper is to explore the computer vision-based solutions for recognizing player actions that can be applied in unconstrained handball scenes with no additional sensors and with modest requirements, allowing a broader adoption of computer vision applications in both professional and amateur settings. This paper presents semi-manual creation of custom handball action dataset based on automatic player detection and tracking, and models for handball action recognition and localization using Inflated 3D Networks (I3D). For the task of player and ball detection, different configurations of You Only Look Once (YOLO) and Mask Region-Based Convolutional Neural Network (Mask R-CNN) models fine-tuned on custom handball datasets are compared to original YOLOv7 model to select the best detector that will be used for tracking-by-detection algorithms. For the player tracking, DeepSORT and Bag of tricks for SORT (BoT SORT) algorithms with Mask R-CNN and YOLO detectors were tested and compared. For the task of action recognition, I3D multi-class model and ensemble of binary I3D models are trained with different input frame lengths and frame selection strategies, and the best solution is proposed for handball action recognition. The obtained action recognition models perform well on the test set with nine handball action classes, with average F1 measures of 0.69 and 0.75 for ensemble and multi-class classifiers, respectively. They can be used to index handball videos to facilitate retrieval automatically. Finally, some open issues, challenges in applying deep learning methods in such a dynamic sports environment, and direction for future development will be discussed. Full article

Breaking is a sports dance modality that will debut for the first time at the Paris 2024 Olympic Games. This dance form combines street dance steps with acrobatics and athletic elements. It complies with gender equality, maintains aesthetic appeal, and is practised indoors. The objective of this study is to assess the characteristics of body composition and nutritional status of the athletes that make up the Breaking national team. This national team was recruited, and they underwent an analysis of body composition using bioimpedance measurement and a nutritional interview status with the completion of a survey on the frequency of the consumption of sports supplements and ergogenic aids. In addition, they completed a consumption questionnaire for a series of food groups with specified protein, lipid, and carbohydrate content. After that, parameters were analyzed in relation to their nutritional status during a complete medical examination at the Endocrinology and Nutrition Service of the Sports Medicine Center of CSD. A descriptive analysis of the results obtained was carried out to find the mean values of the variables analyzed. The analytical parameters described an adequate nutritional status, except for the mean capillary determination of 25-OH-vitamin D3, which was 24.2 ng/dL (SD: 10.3). Bone mineral density values were higher than those of the general population. This is the first time that a study of these characteristics has been carried out on Breakers, so it is highly relevant to increase knowledge in this area in order to conduct nutritional interventions aimed at improving the sports performance of these athletes. Full article

The growth of sport science technology is enabling more sporting teams to implement athlete monitoring practices related to performance testing and load monitoring. Despite the increased emphasis on youth athlete development, the lack of longitudinal athlete monitoring literature in youth athletes is concerning, especially for indoor sports such as basketball. The aim of this study was to evaluate the effectiveness of six different athlete monitoring methods over 10 weeks of youth basketball training. Fourteen state-level youth basketball players (5 males and 9 females; 15.1 ± 1.0 years) completed this study during their pre-competition phase prior to their national basketball tournament. Daily wellness and activity surveys were completed using the OwnUrGoal mobile application, along with heart rate (HR) and inertial measurement unit (IMU) recordings at each state training session, and weekly performance testing (3x countermovement jumps [CMJs], and 3x isometric mid-thigh pulls [IMTPs]). All of the athlete monitoring methods demonstrated the coaching staff’s training intent to maintain performance and avoid spikes in workload. Monitoring IMU data combined with PlayerLoad™ data analysis demonstrated more effectiveness for monitoring accumulated load (AL) compared to HR analysis. All six methods of athlete monitoring detected similar trends for all sessions despite small-trivial correlations between each method (Pearson’s correlation: −0.24 < r < 0.28). The use of subjective monitoring questionnaire applications, such as OwnUrGoal, is recommended for youth sporting clubs, given its practicability and low-cost. Regular athlete education from coaches and support staff regarding the use of these questionnaires is required to gain the best data. Full article

Indoor team sports are characterized by matches that are shorter in duration and with frequent substitution (high-intensity intermittent). The main goal of teams is to best cover athletes’ physiological demands, while meeting their dietary intake needs is critical. The aim of this study is to conduct a systematic review of the dietary intake of indoor team sports athletes and to analyze whether they comply with nutritional recommendations. A search of PubMed-MEDLINE, Web of Science, and Scopus databases from 2008 to July 2022 was conducted and 2727 documents were identified. The studies focused on adult professional or semi-professional volleyball, basketball, handball, or futsal athletes. Two independent researchers screened and extracted the data, with 20 documents included after they met the inclusion criteria. Most of the athletes, both men and women, did not meet the official recommendations based on under-consumption (energy and carbohydrates) or over-consumption (fats). In relation to protein, 28.6% of studies met the recommendations, with 50% of those who did not meet it being due to under-consumption. Although there are references on athletes’ dietary intakes, there are no references considering sexes or types of sport. More adapted recommendations are needed in order to more precisely evaluate athletes’ intake to know if they meet their real nutritional requirements. Full article

Previous studies on performance effects by New Zealand blackcurrant (NZBC) extract used mainly a single exercise task. We examined the effects of NZBC extract in a battery of rugby union–specific tests including speed, agility and strength testing. University male rugby union players (n = 13, age: 21 ± 2 years, height: 182 ± 6 cm, body mass: 87 ± 13 kg) completed two full familiarisations and two experimental visits in an indoor facility. The study had a double blind, placebo-controlled, randomised, crossover design. For the experimental visits, participants consumed NZBC extract (210 mg/day of anthocyanins for 7 days) or placebo with a 7-day wash-out. Testing order was the running-based anaerobic sprint test, the Illinois agility test, seated medicine ball (3 kg) throw, and handgrip strength. With NZBC extract, there may have been an effect for average sprint time to be faster by 1.7% (placebo: 5.947 ± 0.538 s, NZBC extract: 5.846 ± 0.571 s, d = −0.18 (trivial), p = 0.06). However, with NZBC extract there may have been reduced slowing of sprint 2 (d = −0.59 (moderate), p = 0.06) and reduced slowing for sprint 6 (d = −0.56 (moderate), p = 0.03). In the Illinois agility test, there may have also been an effect for the mean time to be faster by 1.6% (placebo: 18.46 ± 1.44 s, NZBC extract: 18.15 ± 1.22 s, d = −0.24 (small), p = 0.07). The correlation between the %change in average sprint time and %change in mean agility time was not significant (Pearson R² = 0.0698, p = 0.383). There were no differences for the seated medicine ball throw distance (p = 0.106) and handgrip strength (p = 0.709). Intake of NZBC extract in rugby union players seems to improve tasks that require maximal speed and agility but not muscle strength. NZBC blackcurrant extract may be able to enhance exercise performance in team sports that require repeated movements with high intensity and horizontal change of body position without affecting muscle strength. Full article

Background: Tug-of-war (TOW) is one of the oldest sports in current existence and is an internationally played activity that includes professional and amateur sport athletes, played according to the rules laid out by the Tug of War International Federation (TWIF). In this type of competition, the two teams of eight members each pull against one another on a rope. The team that pulls the opposing team towards a centerline for a distance of 4 m in two pulls out of three is considered the winning team in an international competition. To the best of the authors’ knowledge, no previous scientific articles have described data during a follow-up period of Championships in TOW. Therefore, the main aim of this study was to analyze the duration of the matches, differentiating between the first (T1) and second pull (T2) of each match. Methods: The pulls were compared in the qualification point phase and the final phase, as well as in each weight category. In addition, any differences between the statistics for each of the four World Championships studied were analyzed. Finally, the total volume of pulls in each weight category was studied, both in the open club competition and in the national team competition. Data were collected from four World Indoor Championships (2010–2016). A total of 1862 matches were registered (3724 pulls), differentiating the first (T1) and second (T2) pull. The data were expressed as means (M) ± standard deviations (SD). Results: (1) The second pull is shorter than the first: T1 < T2, p < 0.001, (Es = 0.452; small effect); (2) T1 and T2 times were longer in the final phase than the qualifying phase: T1 phase2 > T1 phase1, p < 0.05 (ES = 0.469; small effect) and T2 phase2 > T2 phase1, (p < 0.05), (ES = 0.486; small effect); (3) there are statistical differences (p < 0.005) in T1 and T2 at all weights, except for T1 at 500 kg and T2 at 640 kg; (4) the comparison among World Championships does not present significant changes in the duration of the pulls; (5) however, in females, significant differences (p < 0.05) between the 2010 World Championships and the remainder in T1 are observed; (6) the volumes that we should take into account when designing the preparation should be those obtained when 11 teams compete against each other, considering the maximum volume that we could find in the competition. Conclusion: This first aspect of the reality of TOW indoor competitions, specifically the duration of the matches, leads to a better understanding of the demands of the sport and the type of effort required. These ideas may help coaches in the design of training plans, maximizing their specificity and their effectiveness. Full article

Background: The protective restrictions (e.g., lockdowns, quarantines, social and physical distancing) consequent to the global pandemic caused by COVID-19 posited new challenges to athletes practicing competitive team sports. This study aimed to gain an understanding of the impact of the ongoing COVID-19 pandemic on the well-being and sports readiness to train and to compete of competitive female and male athletes practicing outdoor (i.e., rugby, soccer) and indoor (i.e., volleyball, basketball) team sports who were active during the Italian first and second waves of COVID-19. Methods: An online survey assessing demographic characteristics, perceived safety of the training environment, COVID-19 risk, fear of COVID-19, well-being, and sport (training and competition) readiness was administered to 619 team sports players. We examined differences by gender, previous COVID-19 experience, and team sport setting (i.e., outdoor vs. indoor). A moderated mediation analysis was conducted to assess the impact of perceived COVID-19 risk and fear of COVID-19 on athletes’ well-being and sports readiness, using perceived safety of the training environment as a mediator and gender and sport setting as moderators. Results: Indoor team sports and female athletes showed higher perceived COVID-19 risk, while athletes with no-COVID-19 experience reported higher fear of COVID-19. Perceived COVID-19 risk (directly and via perceived safety of the training environment) and fear of COVID-19 were negatively associated with athletes’ well-being and sports readiness. Conclusions: This study highlighted an understanding of the psychological implications of the COVID-19 pandemic, emphasizing the role of the perceived safety of the training environment on athletes’ well-being and sports readiness. Future studies may advance safety-based interventions to promote well-being and a safer return to sport. Full article

In previous studies found in the literature speed (SP), acceleration (ACC), deceleration (DEC), and impact (IMP) zones have been created according to arbitrary thresholds without considering the specific workload profile of the players (e.g., sex, competitive level, sport discipline). The use of statistical methods based on raw data could be considered as an alternative to be able to individualize these thresholds. The study purposes were to: (a) individualize SP, ACC, DEC, and IMP zones in two female professional basketball teams; (b) characterize the external workload profile of 5 vs. 5 during training sessions; and (c) compare the external workload according to the competitive level (first vs. second division). Two basketball teams were recorded during a 15-day preseason microcycle using inertial devices with ultra-wideband indoor tracking technology and microsensors. The zones of external workload variables (speed, acceleration, deceleration, impacts) were categorized through k-means clusters. Competitive level differences were analyzed with Mann–Whitney’s U test and with Cohen’s d effect size. Five zones were categorized in speed (<2.31, 2.31–5.33, 5.34–9.32, 9.33–13.12, 13.13–17.08 km/h), acceleration (<0.50, 0.50–1.60, 1.61–2.87, 2.88–4.25, 4.26–6.71 m/s²), deceleration (<0.37, 0.37–1.13, 1.14–2.07, 2.08–3.23, 3.24–4.77 m/s²), and impacts (<1, 1–2.99, 3–4.99, 5–6.99, 7–10 g). The women’s basketball players covered 60–51 m/min, performed 27–25 ACC-DEC/min, and experienced 134–120 IMP/min. Differences were found between the first and second division teams, with higher values in SP, ACC, DEC, and IMP in the first division team (p < 0.03; d = 0.21–0.56). In conclusion, k-means clustering can be considered as an optimal tool to categorize intensity zones in team sports. The individualization of external workload demands according to the competitive level is fundamental for designing training plans that optimize sports performance and reduce injury risk in sport. Full article

Tug-of-war (TOW) is an internationally played activity including professional and amateur athletes, defined as early as 4000 years ago (as a rope-less version) in the artwork on Egyptian tomb engravings, and is played as per the rules laid out by TWIF, which has 73 member countries and administrative headquarters in the USA. Typically, two teams of “pullers” participate and apply enormous contra directional forces on the pulling rope. Originally, two types of competition are used: knockout and points. This narrative review describes the scientific state of the art of TOW. To the best of the authors’ knowledge, no previous information has been published on this topic. Anthropometric parameters for competitors are near 83.6, lean body mass 69.4, and body fat 16. The VO_2MAX is 55.8 mL/kg/min. In terms of relative strength, the dynamic leg power is 4659.8 N. Endurance TOW elicits minimal muscle damage. Injured strains and sprains comprised over half of all injuries: back (42%), shoulder–upper limb (23%) and knee (17%). Pulling movement in TOW contests can be divided into three phases, namely the “drop”, “hold” and “drive” phases. The maximal pulling force was 1041.6 ± 123.9 N. The percentage of dynamic pulling force in the static maximal pulling force was 75.5 ± 14.4% and the dynamic ranged from 106.4 to 182.5%. There are two gripping styles: indoor and outdoor. The friction characteristics between surface and shoe in TOW is important in determining a suitable shoe for indoor TOW. A waist belt might be a useful piece of equipment for TOW sport. The EMG technique in TOW entails a high degree of dorsal muscle activity during the pulling. The factor of force vanishing was the coordination among athletes. The force vanishing percentage goes from 8.82 ± 5.59 for two contenders to 19.74 ± 2.22 for eight athletes, 6.4% in the sum of two pullers. However, in the drop phase, for female elite TOW team, only the 0.5% of the pulling force was wasted. Future studies are need in order to understand better this historical sport activity. Full article