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42
result(s) for
"Lozano, Demetrio"
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Associations between Inter-Limb Asymmetries in Jump and Change of Direction Speed Tests and Physical Performance in Adolescent Female Soccer Players
2021
The association between asymmetries in jump and change of direction (COD) with physical performance in several sports show inconclusive results. The purposes of this study were to: (1) measure inter-limb asymmetries in three distinct groups in adolescent female soccer players and, (2) to determine the association between inter-limb asymmetries and physical performance in different age groups. Fifty-four players were distributed in three age groups: U-18, U-16 and U-14. All of them performed a series of jumps, sprints and change of direction speed tests. Asymmetries were assessed as the percentage difference between limbs, with the equation: 100/Max value (right and left) * in value (right and left) * −1 + 100. Mean inter-limb asymmetries were 2.91%, 4.82% and 11.6% for 180° COD, single leg hop and single leg countermovement jump tests respectively, but higher percentages of asymmetries were observed in many players individually. U-18 and U-16 showed significant differences on 180° left COD compared to U-14. Effect size (ES): 0.80 and 0.74, respectively; U-18 presented differences on single left leg hop test compared to U-14, ES: −0.72; U-16 also showed differences on 40 m speed compared to U-14, ES 0.87 (All p < 0.05). Jumping and COD physical tests show asymmetries in adolescent female soccer players, but these asymmetries do not interfere with physical performance. The largest asymmetry was observed in the single leg countermovement jump, and no asymmetries between groups were found. Due to the high variability in the direction of asymmetries, it is recommended to consider players’ individual asymmetries for designing specific training programs.
Journal Article
Development and Validation of an Observational Game Analysis Tool with Artificial Intelligence for Handball: Handball.ai
by
García-Sánchez, Carlos
,
Sánchez-López, Sergio
,
Lozano, Demetrio
in
Algorithms
,
Artificial Intelligence
,
Collaboration
2023
Performance analysis based on artificial intelligence together with game-related statistical models aims to provide relevant information before, during and after a competition. Due to the evaluation of handball performance focusing mainly on the result and not on the analysis of the dynamics of the game pace through artificial intelligence, the aim of this study was to design and validate a specific handball instrument based on real-time observational methodology capable of identifying, quantifying, classifying and relating individual and collective tactical behaviours during the game. First, an instrument validation by an expert panel was performed. Ten experts answered a questionnaire regarding the relevance and appropriateness of each variable presented. Subsequently, data were validated by two observers (1.5 and 2 years of handball observational analysis experience) recruited to analyse a Champions League match. Instrument validity showed a high accordance degree among experts (Cohen’s kappa index (k) = 0.889). For both automatic and manual variables, a very good intra- ((automatic: Cronbach’s alpha (α) = 0.984; intra-class correlation coefficient (ICC) = 0.970; k = 0.917) (manual: α = 0.959; ICC = 0.923; k = 0.858)) and inter-observer ((automatic: α = 0.976; ICC = 0.961; k = 0.874) (manual: α = 0.959; ICC = 0.923; k = 0.831) consistency and reliability was found. These results show a high degree of instrument validity, reliability and accuracy providing handball coaches, analysts, and researchers a novel tool to improve handball performance.
Journal Article
Physical Match Performance of Professional Men’s Football Players from Different Competitive Levels During Direct Competition
by
Arjol-Serrano, José Luis
,
Mainer-Pardos, Elena
,
Campo, Roberto López-Del
in
ball possession
,
competitive standard
,
Global positioning systems
2026
The influence of competitive standards on physical performance in professional football remains controversial, particularly when teams from different divisions compete against each other. This study aimed to analyze position-specific differences in physical performance, both in possession and out of possession, between Spanish First and Second Division teams during direct competition. Match data from 25 Copa del Rey fixtures across three seasons were analyzed using a validated multi-camera tracking system. Physical performance variables were examined according to playing position. First Division players accumulated greater total distance during in-possession phases, particularly central defenders (CDs), wide defenders (WDs), central midfielders (CMs), and wide midfielders (WMs), whereas Second Division players covered greater distances during out-of-possession phases, mainly CDs, WDs, and CMs. In addition, First Division CMs exhibited higher high-speed running in possession, while Second Division forwards (FWs) demonstrated greater high-speed running and defensive high-speed running. Differences in maximum velocity were also observed in CDs, with higher values recorded in the First Division. Overall, these findings indicate that physical performance is modulated by the competitive standard and playing position. However, the interpretation of these differences should not be dissociated from the tactical nature of football, as players’ specific positions and the tactical roles derived from them may condition the physical demands imposed during different phases of play, rather than reflecting isolated physical capacity.
Journal Article
Investigating Countermovement and Horizontal Jump Asymmetry in Female Football Players: Differences Across Age Categories
by
Calero-Morales, Santiago
,
Mainer-Pardos, Elena
,
Lozano, Demetrio
in
age categories
,
Age groups
,
Asymmetry
2025
Background: Lower limb asymmetry is a critical factor influencing performance and injury risk in football players. Despite the increasing popularity of women’s football, limited research has examined how asymmetry varies across different age categories. This study aimed to investigate countermovement jump (CMJ) and horizontal jump (HJ) asymmetry in female football players across four age categories (U14, U16, U18, and +18). Methods: Seventy-six female football players from the same club participated in the study. Players performed unilateral CMJ and HJ tests to assess inter-limb asymmetry. A one-way ANOVA and Chi-square tests were conducted to examine age-related differences in asymmetry levels. Results: CMJ asymmetry significantly varied across age groups (p < 0.001), with the highest asymmetry observed in U14 and the lowest in +18. In contrast, HJ asymmetry remained consistently low across all age groups (p = 0.113). No significant correlation was found between CMJ and HJ asymmetry. Additionally, asymmetry levels in CMJ were significantly associated with age (p = 0.003), whereas no such association was observed for HJ. Conclusions: CMJ asymmetry is more prevalent in younger female football players and tends to decrease with age, suggesting that neuromuscular development plays a role in reducing asymmetry over time. These findings highlight the importance of monitoring asymmetry levels across different age groups to optimize training interventions and injury prevention strategies.
Journal Article
Training Tasks vs. Match Demands: Do Football Drills Replicate Worst-Case Scenarios?
by
Bataller-Cervero, Ana Vanessa
,
Arjol-Serrano, José Luis
,
Mainer-Pardos, Elena
in
Decision making
,
football
,
football drills
2025
This study analyses the physical performance variables involved in different training tasks aimed at replicating the worst-case scenarios (WCSs) observed during official matches in professional football, with a focus on playing positions and occurrences within a 1 min period. Data were collected from 188 training sessions and 42 matches of a Spanish Second Division team during the 2021/2022 season. All data were reported on a per-player basis. GPS tracking devices were used to record physical variables such as total distance, high-speed running (HSR), sprints, accelerations, decelerations, and high metabolic load distance (HMLD). Players were grouped according to their match positions: central defenders, wide players, midfielders and forwards. The results showed that none of the training tasks fully replicated the physical demands of match play. However, task TYPEs 11 (Large-Sided Games) and 9 (small-sided games with orientation and transition) were the closest to match demands, particularly in terms of accelerations and decelerations. Although differences were observed across all variables, the most pronounced discrepancies were observed in sprint and HSR variables, where training tasksfailed to reach 60% of match demands. These findings highlight the need to design more specific drills that simulate the intensity of WCS, allowing for more accurate weekly training load planning. This study offers valuable contributions for optimising performance and reducing injury risk in professional footballers during the competitive period.
Journal Article
Influence of contextual factors on physical demands and technical-tactical actions regarding playing position in professional soccer players
by
Lozano, Demetrio
,
Díez, Adrián
,
Torrontegui-Duarte, Marcelino
in
Analysis
,
Coaches & managers
,
Contextual game factors
2021
Background
The aim of this study was to analyse the physical demands and technical-tactical actions for each playing position according to game location and final outcome in professional soccer players.
Methods
A convenience sample was obtained from twenty-one professional male soccer players, belonged to same soccer team of the Spanish Second Division. Players’ physical demands were monitored during each match using a portable 18 Hz GPS unit and 600 Hz triaxial accelerometer. These analysed demands were total distance, moderate speed running distance (>14.4 km·h
-1
), high-speed running distance (>19.8. km·h-1), sprint distance (>25.0 km·h
-1
), number of accelerations between 2 and 4 m·s
-2
and above 4 m·s
-2
, and number of decelerations between 2 and 4 m·s
-2
and above 4 m·s
-2
. The data related to technical-tactical actions were obtained from WyScout®, a computerized multiple-camera tracking system based on the OPTA® track analysis tool. The obtained indicators were general, defensive and offensive.
Results
For all players, higher total distance (p = 0.045; effect size [ES] = 0.24, small effect) was covered and greater deceleration 2-4 m·ss
-2
(p = 0.001; ES = 0.68, medium effect) was performed when the team plays at home and lose and for all players, playing at home and winning demanded higher defensive volume (p =0.014; ES = − 1.49, large effect) and nº interceptions (p =0.031; ES = − 1.40, large effect) in comparison to playing at home and losing.
Conclusions
The physical demands and technical-tactical actions vary when contextual game factors (i.e., match location and final outcome) are considered. We can confirm that, although the training of physical demands does not influence the final result of the match, the training of technical tactical actions could help to achieve an optimal performance of the team to win matches.
Journal Article
Correlation Between Physical Activity and Psychological Problems in Secondary School Students in Spain
by
Mainer-Pardos, Elena
,
Pueyo Gutiérrez-Rivas, Pablo
,
Lozano, Demetrio
in
adolescence
,
Adolescents
,
Analysis
2025
Physical activity (PA) has been identified as a protective factor for adolescent mental health. This study analysed the association between PA and levels of anxiety, depression, and stress among adolescents, considering gender, educational stage, and type of sport. A cross-sectional design was conducted with 106 Spanish secondary school students aged 12–16 years. Data were collected through a self-reported questionnaire on PA participation and the validated DASS-21 scale. Descriptive statistics, chi-square (χ2) tests, and adjusted residual analyses were performed. The results showed a significant negative association between PA and anxiety (χ2 = 303.34, p < 0.01), stress (χ2 = 310.64, p < 0.01), and depression (χ2 = 324.32, p < 0.01). Non-athletes presented higher levels of psychological problems compared with active peers, while girls and older students showed greater vulnerability. Adolescents involved in team sports exhibited lower anxiety and stress than those participating in individual sports. In conclusion, higher participation in physical activity, particularly team-based disciplines, is associated with better mental health in adolescents. These findings reinforce the importance of integrating regular physical activity into school contexts to support psychological well-being during adolescence.
Journal Article
Horizontal jump asymmetries are associated with reduced range of motion and vertical jump performance in female soccer players
by
Mainer-Pardos, Elena
,
Bishop, Chris
,
Carton-Llorente, Antonio
in
Ankle
,
Asymmetry
,
Bilateral asymmetry
2023
Background
Performance in jumping and change of direction tests are good proxies to reflect the skill level during soccer-specific actions. Greater inter-leg asymmetries have been identified as a risk factor for developing acute and overuse injuries and jeopardizing soccer performance. The aim of this study was to assess the association between asymmetry in the unilateral vertical and horizontal jump tests, ankle range of motion, linear velocity, and change of direction in a sample of highly trained adult female soccer players.
Methods
Thirty-eight highly trained female soccer players underwent a testing protocol including ankle dorsiflexion, single leg jumps for height (CMJ), distance (HJ), 40 m sprint and 180° change of direction tests.
Results
Within-session reliability was acceptable (CV ≤ 7.9%), and relative reliability showed good to excellent (ICC: 0.83 to 0.99). The one-way ANOVA reported higher inter-limb differences for change of direction deficit (10.9 ± 8.04%) and single leg CMJ (5.70 ± 5.22%). Pearson correlations highlighted significant relationships between horizontal jump asymmetries and ankle dorsiflexion (
r
= -0.41), CMJ (
r
= -0.36 to -0.49) and HJ (
r
= -0.28 to -0.56).
Conclusions
Assessing inter-limb asymmetries through different methods can help scientists understand the specificity of their detrimental effects on soccer performance. Practitioners should be aware of these specificities as well as the magnitude and direction of the asymmetries when aiming to improve specific on-field skills.
Journal Article
Global Positioning System Analysis of Physical Demands in Small and Large-Sided Games with Floaters and Official Matches in the Process of Return to Play in High Level Soccer Players
by
Gonzalo-Skok, Oliver
,
Lozano, Demetrio
,
Arjol, José Luis
in
Adolescent
,
Athletic Performance - physiology
,
Geographic Information Systems
2020
The aim of this study was twofold: (i) to analyze the physical demands in the return to play (RTP) process of high-level soccer players in the role of floater in different soccer sided games (SGs) formats (i.e., 4vs4 + 2 and 8vs8 + 1); and (ii) to analyze the differences in physical demands encountered by regular and floater players among the SGs formats and official matches by means of global positioning system technology (GPS APEX pod, North Ireland) was used. Twenty-six highly trained, male soccer players (U16 years) participated in this investigation. Players were classified into two groups: 23 regular and 3 floater players, a total of eight SGs were analyzed, which involved the recording of 80 observations of regular and floater players. Match-play players showed most likely–probable differences in distance covered at high-intensity per minute (D > 14.4/min), at high-speed running per minute (D > 21/min), and peak velocity (Vpeak) in comparison to floaters in the 8vs8 + 1 LSG (large-side-games), and presented most likely differences in accelerations >2/min in comparison to match-play players. Therefore, the use of floaters during the last phase of the RTP (return to play) seems to be a useful strategy for progressive reintroduction into specific training (1) floater in the 4vs4 + 2 SSG; (2) floater in the 8vs8 + 1 LSG; (3) regular player in the 4vs4 + 2 SSG; and (4) regular player in the 8vs8 + 1 LSG before starting full trainings and returning to competition.
Journal Article
Evaluation of 10-Week Neuromuscular Training Program on Body Composition of Elite Female Soccer Players
by
Arjol-Serrano, José Luis
,
Mainer-Pardos, Elena
,
Nobari, Hadi
in
analysis of variance
,
Anthropometry
,
Body composition
2022
(1) Background: This study was conducted to investigate the effects of a 10-week neuromuscular training program (NMT) on the sum of six skinfolds (Σ6S) and body composition variables in elite female soccer players. (2) Methods: Forty-four Spanish elite female soccer players (age: 24.0 ± 4.2 years; height: 164.3 ± 5.5 cm; body mass: 60.4 ± 5.5 kg; body mass index (BMI): 22.4 ± 2.2 kg/m2) were randomly assigned to a control group (CG) or to an experimental group (EG). Participants in the EG completed a specific NMT program of 24 min, three times per week, which included exercises from six different categories (mobility, dynamic stability, anterior chain strength, lumbopelvic control, posterior chain strength, and change of direction). The CG followed their normal strength and conditioning program. Pre- and post-intervention assessments included anthropometric measurements (weight, height, limb circumferences, and bone breadths), and subsequently, body composition factors BMI, Σ6S, body mass, muscle mass, and lean body mass were calculated. Nutrition was standardized by a nutritionist and also load monitored. (3) Results: A two-way mixed analysis of variance (group × time) revealed that there was a significant (p ≤ 0.001) group × time interaction between body mass, fat mass, and Σ6S in favor of NMT. A significant interaction was also observed for body skeletal muscle mass and lean body mass favoring NMT. (4) Conclusions: The application of an NMT program seems to be a useful strategy to improve body composition in elite female soccer players.
Journal Article