Artículos (Motricidad Humana y Rendimiento Deportivo)
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Artículo Mechanical and metabolic responses during high-intensity training in elite 800-m runners(Georg theme Verlag, 2021) Bachero Mena, Beatriz; González Badillo, Juan José; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoThe purpose of this study was to describe the mechanical and metabolic responses of a typical high-intensity training session in high-level 800-m athletes. Nine male high- level 800-m athletes (personal best 1:43-1:56 min:ss) performed a typical high-intensity interval training session consisting in 5x200-m, with 4 min rest. Countermovement jump and blood lactate were measured at rest and after each running bout. Running times, ground contact times and stride length were also measured. Running times and lactate (p<0.01) progressively increased from the first to the last running bout. Jump height (p<0.01) and stride length (p<0.05) progressively decreased from the first running bout to the last. A significant negative relationship (p<0.001; r =-0.83) was found between the individual values of jumping height and blood lactate concentration; and a significant positive relationship (p<0.01; r=0.67) was observed between the time in 200-m and the contact times. In conclusion, the results demonstrated that the typical training session performed by 800-m athletes produced a high level of fatigue showed up by significant alterations on the mechanical and metabolic response. The impairments observed on the mechanical and metabolic parameters may indirectly reflect a state of energy deficit of the muscle contractile machinery and a reduction on the force-generating capacity.Artículo Current guidelines for the implementation of flywheel resistance training technology in sports: a consensus statement(Adis Int. Ltd., 2024) Beato, Marco; Keijzer, Kevin L de; Muñoz López, Alejandro; Raya González, Javier; Pozzo, Marco; Alkner, Bjorn A; Dello Iacono, Antonio; Vicens Bordas, Jordi; Coratella, Giuseppe; Hoyo Lora, Moises del; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoFlywheel resistance training has become more integrated within resistance training programs in a variety of sports due to the neuromuscular, strength, and task specific enhancements reported with such training. Objective: This paper aimed to present the consensus reached between internationally recognized experts during a meeting on current definitions and guidelines for the implementation of flywheel resistance training technology in sports. Methods: Nineteen experts from different countries took part in the consensus process: 16 of them were present at the consensus meeting (18th of May 2023) while 3 submitted their recommendations by e-mail. Prior to the meeting, evidence summaries were developed relating to areas of priority. This paper discusses the available evidence and consensus process from which recommendations were made regarding the appropriate use of flywheel resistance training technology in sports. The process to gain consensus had five steps: 1) performing a systematic review of systematic reviews, 2) updating the most recent umbrella review published on this topic, 3) first round discussion among a sample of the research group included in this consensus statement, 4) selection of research group members – process of the consensus meeting and formulation of the recommendation, and 5) consensus process. The systematic analysis of the literature was performed to select the most updated review papers available on the topic which resulted in 9 articles; their methodological quality was assessed according to AMSTAR 2 (Assessing the Methodological Quality of Systematic Review 2) and GRADE (Grading Recommendations Assessment Development and Evaluation). Statements and recommendations scoring 7-9 were considered appropriate. Results: The recommendations were based on evidence summary and researchers’ expertise; the consensus statement included 3 statements and 7 recommendations for the use of flywheel resistance training technology. These statements and recommendations were anonymously voted on and qualitatively analyzed. The three statements reported a range score from 8.1 to 8.8., therefore, all statements included in this consensus were considered appropriate. The recommendations (from one to seven) had a score ranging from 7.7 to 8.6, therefore, all recommendations were considered appropriate. Conclusions: Because of the consensus achieved among the experts of this project, it is suggested that practitioners and researchers should adopt the guidelines reported in this consensus statement regarding the use of flywheel resistance technology in sports.Artículo Is possible an eccentric overload in a rotary inertia device? Comparison of force profile in a cylinder-shaped and a cone-shaped axis devices(Taylor & Francis, 2020) Núñez, F. Javier; Galiano de la Rocha, Carlos; Muñoz López, Alejandro; Floria, Pablo; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoThe aims of this study were to compare the force profile of using a horizontal cylinder-shaped axis or a vertical cone-shaped axis to provide resistance in rotary inertia devices, and to report the evolution of kinetic and kinematic variables in experienced athletes during a half-squat exercise. Twenty two healthy active men participated in the assessment of time, peak velocity, peak force, time to reach the peak force, average force, impulse, and range of movement, during a half-squat incremental test performed on conical inertial device (CP) and on cylinder inertial device (YY). The analysis showed that YY during CON-ECC phased generates substantial higher peak_force, mean_force, impulse, time, and a lower peak_velocity, than CP. We never obtained eccentric overload for peak_force or mean_force. CP offers less resistance to accelerate-decelerate the movement with respect to YY, we need checking whether eccentric overload it is being produced, and the impulse was the only kinetic variable that was able to discriminate between the inertias and devices. .Artículo Effects of resistance training on physical performance in high-level 800-meter athletes: a comparison between high-speed resistance training and circuit training(Lippncott Williams & Wilkins, 2021) Bachero Mena, Beatriz; Pareja Blanco, Fernando; González Badillo, Juan José; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoThis study compared the effects of two resistance training programs during 25 weeks on physical performance and hormonal response in high-level 800 m athletes. Thirteen male athletes (800 m personal best: 1:43-1:58 min:ss) were divided into 2 groups: highspeed resistance training group (RTG) (n = 6) and circuit training group (CTG) (n = 7). Three tests (T1, T2 and T3) including sprint and 800 m running, strength exercises and blood hormones samples were carried out. Both groups showed improvements in 800 m performance (RTG: likely positive, 80/20/0%; CTG: very likely positive, 98/2/0%), however, RTG showed an additional improvement in 200 m (likely positive, 85/15/0%), countermovement jump (very likely positive, 98/2/0%), and squat (likely positive, 91/9/0%), whereas CTG reached likely positive (88/11/1%) effects in CMJ and unclear/possibly negative effects in the rest of the strength variables analyzed. Concerning hormones, RTG resulted in a likely increase (83/15/3%) in testosterone from T1 to T3, and CTG showed a likely increase (79/17/4%) in cortisol from T2 to T3, remaining the rest of the hormones analyzed unclear. These results suggest that a resistance training characterized by high-speed and low-volume produced better improvements in both strength and running performance than a circuit training, accompanied by little changes in the hormonal response. Middle-distance Running, Countermovement Jump, Squat, Hormones,Artículo Eccentric overload differences between loads and training variables on flywheel training(Termedia Publishing House Ltd, 2023) Muñoz López, Alejandro; Nakamura, Fábio Yuzo; Beato, Marco; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoObjective: there is considerable debate about the existence of a real eccentric overload in flywheel exercises. This study aimed to analyse the differences in concentric:eccentric mechanical output ratios between different loads and variables in the flywheel squat exercise. Methods: twenty physically active men (22.9 ± 2.2 years, height: 1.8 ± 0.1 m, weight: 79.6 ± 8.2 kg) performed a loading test using five moments of inertia. Angular speed was measured using a rotary encoder, while the vertical force was measured using force plates. For each variable (angular speed, angular acceleration, power, vertical force, and torque), mean and peak values were calculated for concentric and eccentric phases to allow comparisons across the loads. We tested the possible differences in Load x Phase (concentric and eccentric) and Load x Variable. The level of significance was established as p < 0.05. Results: a significant Load x Phase interaction was found in mean angular speed, peak vertical force, peak angular acceleration, peak power and peak torque. Higher eccentric overload values were observed with speed-derived variables (angular speed, angular acceleration and power). Conclusions: in conclusion, speed-derived peak variables and lower loads are more likely to show an eccentric overload and can be used to monitor responses to flywheel training.Artículo The use of real-time monitoring during flywheel resistance training programmes: how can we measure eccentric overload? A systematic review and meta-analysis(Termedia Publishing House, 2021) Muñoz López, Alejandro; De Souza Fonseca, Fabiano; Ramírez Campillo, Rodrigo; Gantois, Petrus; Nuñez, Francisco Javier; Nakamura, Fabio Y.; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoThis systematic review and meta-analysis aimed to analyze the technologies and main training variables used in the literature to monitor flywheel training devices in real-time. In addition, as the main research question, we investigated how eccentric overload can be effectively monitored in relation to the training variable, flywheel shaft type device and the moment of inertia selected. Methods: The initial search resulted in 11,621 articles that were filtered to twenty-eight and seventeen articles that met the inclusion criteria for the systematic review and meta-analysis, respectively. Results: The main used technologies included force sensors and rotary/linear encoders, mainly to monitor Peak- or Mean-Force, -Power or -Speed. Not always an eccentric overload was achieved using flywheel devices. The eccentric overload measurement was related to the main outcome selected. While Mean-Force (p = 0.011, ES= 0.84) and Mean-Power (p<0.001, ES= -0.30) favored the concentric phase, Peak-Power (p<0.001, ES= 0.78) and Peak-Speed (p<0.001, ES= 0.37) favored the eccentric phase. In addition, the lower moments of inertia (i.e., from 0.01 to 0.2 kg·m2) and a cylindrical shaft type (i.e., vs conical pulley) showed higher possibilities to achieve the eccentric overload. Conclusions: a wide variety of technologies can be used to monitor flywheel devices, but to achieve eccentric overload, a flywheel cylindrical shaft type with low moments of inertia are advised to be usedArtículo Variability in the application of eccentric force using different rotary inertia devices may influence the treatment of tendinopathy(Human Kinetics, 2022) Nuñez, Francisco Javier; Galiano De La Rocha, Carlos; Muñoz López, Alejandro; Floria, Pablo; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoHigh intra-set variability has been considered as a potential aid in the treatment of tendinopathy by producing forces in variable and unpredictable contexts that allow the athlete to return to sport pain-free. The aim of this study was to compare the intra-set variability in force profiles between different rotational inertia devices (RIDs) during concentric (CON) and eccentric (ECC) phases of movement, and between different moments of inertia. Thirty-nine men performed a half-squat incremental test on two different RIDs: a horizontal cylinder (YY) and a vertical cone-shaped axis (CP). Intra-set variabilities in vertical force and velocity were analyzed using average coefficients of variation. RID squat exercise produced force intra set variability. The ECC phase of the movement showed more intra-set variability in force output than the CON phase. ECC CP showed a higher intra-set variability in force than ECC YY. This study demonstrated that using an RID to provide resistance in squat-training of athletes produced a high intra-set variability in the application of force.Artículo Stable vs. variable eccentric load. Do they induce different training and physical performance outcomes?(Taylor & Francis, 2023) Galiano, C; Floria, P; Muñoz Lopez, Alejandro; Villarreal, ES. De; Nuñez, FJ; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoSince most movement on the field require athletes to produce forces in variable and unpredictable context, the use of training programs based on identical repetitions of an exercise may not be optimal for movement transference. Therefore, the aim of this study was to analyze the effects of unexpected eccentric load variability during resistance training in team sport players. Sixty-three men randomly allocated in two experimental groups (Variable (VTG) and stable (STG) training group) and control group: (CG) volunteered to participate in this study. Experimental groups trained with the same average load of half-squat exercise twice a week for six weeks using rotary inertial devices (RIDs) with (VTG) and without (STG) an unexpected variability of the load. Squat force was measured for every session with force plates. Counter-movement jump (CMJ), sprint, and change of direction performances were measured pre and post-test. CMJ performance improved for VTG (p= 0.014; ES= 0.7) and STG (p=0.005; ES= 0.79) but not for CG. Exposure to high eccentric forces with RIDs lead athletes to improve physical performance in the trained force-vector but, since RIDs induce in high levels of variability per se, increasing the level of variability of the exercise will not add benefits to physical performance and training outcomesArtículo Maximum velocity during loaded countermovement jumps obtained with an accelerometer, linear encoder and force platform: A comparison of technologies(2019) Ferro, Amelia; Floría, Pablo; Villacieros, Jorge; Muñoz López, Alejandro; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoThe maximum velocity (Vmax) reached during countermovement jumps (CMJ) has been considered a performance indicator to evaluate the vertical jump ability. The aim of this study was to compare Vmax during loaded CMJ (CMJload) using three different technologies to show a criterion for to select the more appropriate depending of the use. Nine recreationally active men performed a CMJload test. Five jumps were made in each of 6 series with a 20-kg barbell + 0, + 5, + 10, + 15, + 20 and + 25 kg, with 2 seconds of rest between the jumps and 5 minutes of rest between the series to explore a wide range of speeds. Vmax was obtained from force platform, inertial device and linear encoder technologies. To compare devices, Bland-Altman plots and mean differences were used. The reproducibility was tested using the intraclass correlation coefficient (ICC) for single measures and typical error (TE). All technologies showed high levels of reproducibility, ICC higher than 0.75 and TE lower than 10%. There were non-significant differences in Vmax between each pair of technologies (linear encoder 2.11 ± 0.24 m·s-1, inertial device 2.11 ± 0.26 m·s-1, force platform 2.13 ± 0.25 m·s-1) reporting a very low bias. Although the limits of agreement between the different technologies evaluated were high (± 0.33 m·s-1). In conclusion, the accelerometer, linear encoder and force platform were suitably reliable to be used to measure the Vmax during loaded vertical jumps but theirs values were not interchangeable.Artículo Real-time mechanical responses to overload and fatigue using a flywheel training device(Elsevier, 2021) Muñoz López, Alejandro; Pozzo, Marco; Floria, Pablo; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoPurpose: This study aimed to analyze mechanical performance and mechanical losses across different sets and repetitions of unilateral leg extensions under flywheel loading conditions. Methods: In a cross-over design, 23 physically active participants executed 3 sets of 30 repetitions using two different loads. Angular speed, angular acceleration and power were monitored, and mean and peak values of these variables were calculated for each set of repetitions. We analyzed time-course differences every five repetitions (described as ‘clusters’). Differences in the mechanical profile for Load by Set and in the mechanical losses for Load by Set by Cluster repetitions were analyzed using an ANOVA repeated measures test. A Principal Components (PC) analysis was also conducted. Results: Only peak acceleration showed a significant Set by Load interaction (p=0.006) in mechanical performance. At the intra-set level, all consecutive clusters showed a significant decrement in all variables, but with different magnitudes (speed < acceleration < power). Although all variables showed significant Set by Cluster and Load by Cluster interactions, only the acceleration variables showed a significant Set by Load interaction (p<0.05). All the variables showed a single PC. Higher fatigue was found around the concentric peak for each variable. Conclusions: The most sensitive variable for detecting fatigue using real-time feedback seems to be the angular acceleration of the flywheel. Peak acceleration can be used to monitor training workload and training volume in real time in leg extension exercises using flywheel training devicesArtículo Soccer matches but not training sessions disturb cardiac-autonomic regulation during national soccer team training camps(Routledge . Taylor & Francis Group, 2021) Muñoz López, Alejandro; Nakamura, Fabio; Naranjo Orellana, José; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoHeart rate variability (HRV) can be used to monitor changes in autonomic nervous system (ANS) function. Monitoring HRV via the natural log of the root-mean-square difference of successive normal RR intervals (lnRMSSD), a decrease was related to lower parasympathetic activity and a fatigued state, and an increase was related to higher parasympathetic activity and better physical conditioning. This study analysed daily ANS function changes among professional soccer players at national team training camps during preparation for the UEFA Eurocup 2016. Method: 23 professional soccer players were distributed into two groups: First eleven (players who played more than 60 minutes per soccer match) and Reserves (the rest of the players). HRV and session training load (s-TL) were monitored. Between-group daily differences were assessed using two-way mixed repeated measures ANOVA. Results: s-TL significantly increased (p<0.05) at the beginning of each camp and significantly decreased the day before the soccer match (p<0.001). There was a significant time by group interaction in lnRMSSD (p=0.024). Changes were found in the First eleven group from match day +1 to match day +2 (+0.523 ms, p=0.003). After the soccer match, there were between-group differences (p<0.05) at +24h and +72h in lnRMSSD. Conclusions: During national team training camps, ANS function was only modified 24h and 72h after playing soccer matches, in players who played a minimum of 60 minutes. This knowledge can help coaches to monitor the impact of soccer matches during training camps to detect fatigue and improve recoveryArtículo Effects of different velocity loss thresholds on passive contractile properties and muscle oxygenation in the squat exercise using free weights(Lippincott Williams & Wilkins, 2022) Muñoz López, Alejandro; Marín Galindo, Alberto; Corral Pérez, Juan; Costilla, Manuel; Sánchez Sixto, Alberto; Sañudo Corrales, Francisco de Borja; Casals, Cristina; Ponce González, Jesús G.; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento Deportivo; Universidad de Sevilla. Departamento de Educación Física y Deporte; Universidad de Sevilla. CTS972: Análisis Biológico y Funcional del Ejercicio FísicoThe current study assessed the impact between different velocity loss thresholds on changes in the muscle contractile properties and muscle oxygenation after a single resistance training session. 30 physically-active men participated in a cross-over study performing three sets of the squat exercise at a lifted speed of ≈ 0.75 m·s -1, with two different velocity loss thresholds: 20% (VL20) vs 40% (VL40) in a randomized order. Contractile properties of the knee extensor muscles were tested using Tensiomyography. In addition, muscle oxygenation was continuously measured from baseline until the end of the exercise session. The Vastus Lateralis showed a significant Moment by Condition interaction in Time Delay (p=0.044), Muscle Displacement (p=0.001), and Contraction Velocity (p=0.007), with greater reductions in VL40. During the execution, the oxygenated haemoglobin and the tissue oxygen index decreased, while the deoxygenated haemoglobin increased (Moment as the main effect, p<0.05), but without a Moment by Condition interaction. In addition, VL40 showed a lower deoxygenation slope in Set 1 (-0.468 %·s-1, p= 0.001) and Set 3 (-0.474 %·s-1, p= 0.037) as well as higher losses in Set 1 (-41.50%, p= 0.003), Set 2 (-41.84%, p= 0.002), and Set 3 (-62.51%, p<0.001). Finally, the recovery slope and increment during the first minute after each set were not significantly different between conditions. In conclusion, using a velocity loss of ≈ 40% resulted in higher neuromuscular impairment and more time under a lower oxygen supply compared to using a velocity loss of ≈ 20% in the squat exercise after a single resistance training session.Artículo Eccentric-concentric ratio: a key factor for defining strength training in soccer(Thieme, 2019) Nuñez, F. Javier; Hoyo Lora, Moisés del; Muñoz López, Alejandro; Sañudo Corrales, Francisco de Borja; Otero Esquina, Carlos; Sanchez, Hugo; Gonzalo Skok, Oliver; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoArtículo Determinant actions in men's professional padel performance(Taylor & Francis, 2024) Pelaez Romero, Guillermo; González Silva, Jara; Conejero, Manuel; Fernández Echeverría, Carmen; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento Deportivo; Universidad de Sevilla. Departamento de Ingeniería y Ciencia de los Materiales y del TransporteThe main objective of the present research was to know the variables of the game in padel determining in the sport performance in men’s category in the season 2022-2023 in World Padel Tour. The independent variables considered in this study were: court side, dominance, stroke type, origin of the ball, net distance, shot direction and trajectory. The dependent variable was the effectiveness of the game actions. 4505 game actions were analysed during the finals of the four masters (Marbella, Valladolid, Madrid, and Buenos Aires) and the final master (Barcelona) of the 2022-2023 season of the World Padel Tour were analysed. The multinomial logistic regression applied showed that, the variables that predict the effectiveness of the game actions are: stroke type, net distance, shot direction and trajectory. Specifically, our results show us that the stroke type that we must use to be more effective and score points is the smash, we must hit down the line, from areas close to the net and with a downward trajectory. These results show the characteristics of the game actions that determine the performance with the aim that they can help guide coaches in the training process of padel playersArtículo Match analysis within the coaching process: a critical tool to improve coach efficacy(Taylor & Francis, 2017) Fernández Echeverría, Carmen; Mesquita, Isabel; González Silva, Jara; Claver, Fernando; Moreno, Perla M; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoMatch analysis is a topic of current interest in sports science. It is widely used across a range of different sports and has, in the process, demonstrated a number of different performance indicators. For sports coaches, match analysis is perhaps one of the most important tools for analysing games and extracting valuable information about their own and opposing teams. However, despite the usability of this tool, little is known about how information obtained from game analyses affects the planning of training, the setting of goals and the choice of strategic approach by coaches. It is therefore necessary to conduct case studies which evaluate the usefulness of match analysis in an applied context such as high-level sport. This review has two main goals: (1) To provide an overview of empirical studies of match analysis in Volleyball; and (2) to attempt to demonstrate the benefits of using match analysis as a support tool for sports training, and the need to develop studies which analyse the use of this tool and its influence on high-level training processesArtículo Perceptions of elite volleyball players on the importance of match analysis during the training process(Taylor & Francis, 2018) Fernández Echeverría, Carmen; Mesquita, Isabel; Conejero, Manuel; Moreno, Perla M; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoIn the present study, athletes from an elite female volleyball team (N = 12) experienced an intervention programme, based on the provision of information from match analyses, throughout a single season. The information provided related to individual and team competitive performances, as well as the performances of opposition teams. Our aim was to assess the study athletes’ perceptions of this intervention once the season had ended. We used a semi-structured interview method and a thematic analysis of interview content using the categorisation and coding procedures. Regarding the match analysis related to the study team, 95.65% of the comments made by the players were positive and only 4.34% was negative. Players indicated it was useful to understand the negative aspects of their game in order to correct them, and positive aspects in order to motivate weekly training. All of the comments regarding match analyses of opposition teams were positive, with one highlight being that this helped players to be informed about the oppositions’ game and to be more prepared for upcoming matchesArtículo Analysis of the variables that predict serve efficacy in young volleyball players(Taylor & Francis, 2015) Fernández Echeverría, Carmen; Gil, Alexander; Moreno, Alberto; Claver, Fernando; Moreno, Perla M; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoThe main objective of this research study was to analyse, in volleyball, the prediction level of different serve variables on its efficacy. The sample was comprised of 2038 serve actions, corresponding to 36 female teams participating in the Spanish Championship female in 2010 in the Under-14 and Under-16 categories. The independent variables were: serve zone, serve type, striking technique, in-game role of the server, reception zone, receiver player and serve direction. The dependent variable was serve efficacy. The multinomial logistic regression applied showed that all the variables considered in the study, except for serve direction and striking technique, predicted the efficacy of serve. The probability of increasing serve efficacy was achieved through: executing standing serves, serving to the space between players and serve reception by players other than the libero. These results can guide coaches in volleyball player training processes, with respect to the serve actionArtículo Cognitive and emotional factors as predictors of performance indicators in young volleyball players(Taylor & Francis, 2016) Claver Rabaz, Fernando; Jiménez, Ruth; García González, Luís; Fernández Echeverría, Carmen; Moreno. M. P; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoIn recent years, there has been much discussion about the need for using the key performance indicators, in order to guide training and consequently, competition. Some studies used the game action efficacy, the match result or the classification as a reference, while others used player’s or coach’s perception of performance. Thus, a predictive study with the aim to analyze several performance indicators in volleyball formative stages, was realized. The sample consisted of 164 players from all 16 teams (male and female) of an Under-16 volleyball league. Dependent variables: game action efficacy, classification and player’s perceived performance. Independent variables: procedural knowledge, decision-making, motivation and basic psychological needs. The results of the regression analysis showed that game action efficacy and classification were predicted only by cognitive variables (knowledge and decision-making), while players’ perceived performance was predicted by the basic need of relatedness. The different performance indicators appear to measure different realities, being predicted by different variables. Mixed methods could provide a better understanding of performance than a single analytic approach alone, combining descriptions from the inside and from the outsideArtículo Accentuated eccentric resistance training: Effects on physical performance in male and female athletes(Taylor and Francis Online, 2023) Galiano, Carlos; Floria, Pablo; Muñoz López, Alejandro; Núñez, Francisco Javier; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoThis study aimed to compare the effects of an accentuated eccentric training programme on physical performance between men and women. Distributed in two groups by gender, 21 male and 21 female athletes performed four sets of seven repetitions of the half-squat exercise twice per week for 6 weeks. Both groups lifted the same absolute load using a rotary inertial device. To accentuate the eccentric action, the eccentric load was twice as heavy as the concentric load. Vertical jump, sprint, and change of direction (COD) performances were measured pre- and post-intervention. To measure strength gains, vertical ground reaction forces were measured for each repetition of the entire training programme. Vertical jump improved post-intervention (MG: 33.88 ± 4.94 to 35.41 ± 4.86; FG: 20.60 ± 4.62 to 22.12 ± 4.32; p < 0.001; η2p = 0.42), while sprint (MG: 3.08 ± 0.11 to 3.07 ± 0.13; FG: 3.66 ± 0.23 to 3.64 ± 0.23) and COD (MG: 7.77 ± 0.42 to 7.61 ± 0.47; FG: 8.44 ± 0.58 to 8.38 ± 0.57) remained unchanged. Concentric and eccentric forces increased for both groups from session 1 to 4 (p < 0.001; η2p >0.39), while only peak eccentric forces increased until session 12 (p = 0.009; η2p = 0.21). In conclusion, even when men are able to produce greater forces with similar loads, accentuated eccentric RT produces similar strength and strength-related adaptations in male and female athletes.Artículo Effects of Beet Juice on Performance in Competitive Swimmers(Universidad Católica de Murcia, 2024) Leitão, Luis; Sánchez Oliver, Antonio Jesús; Domínguez Herrera, Raúl; Universidad de Sevilla. Departamento de Motricidad Humana y Rendimiento DeportivoEste estudio analizó el efecto de la suplementación con zumo de remolacha (BRJ) en una sesión de natación intermitente con altas demandas glucolíticas sobre el rendimiento, variables biomecánicas (velocidad, longitud de brazada, frecuencia del ciclo, índice de brazada), concentraciones de lactato en sangre (BLa) y índice de esfuerzo percibido (RPE). Diseño: en un diseño cruzado, doble ciego, controlado con placebo, los participantes ingirieron BRJ (~12,8 mmol de nitrato) o un placebo (PLA) en dos sesiones experimentales diferentes. Métodos: 10 nadadores adolescentes competitivos (6 mujeres y 4 hombres, rango de edad de 13 a 16 años) ejecutaron una prueba de natación consistente en un protocolo de nado de 8 x 50 m después de tomar BRJ o PLA. Se evaluaron los parámetros biomecánicos, RPE después de cada serie y BLa antes y después del ejercicio. Resultados: BRJ mejoró el tiempo en la prueba de natación (p=0,004) con un mejor tiempo medio (p=0,004) y tiempo en la serie más lenta (p=0,041). No se informaron diferencias entre BRJ y PLA para los parámetros biomecánicos, BLa o RPE. Conclusiones: BRJ mejoró el rendimiento en natación y la relación entre trabajo y RPE, sin ningún efecto sobre los parámetros biomecánicos. Por tanto, la ingesta de BRJ podría ser beneficiosa para los nadadores durante las sesiones intermitentes de alta intensidad.