Luis Javier Chirosa Ríos

Context : The athletic shoulder (ASH) test traditionally evaluates upper limb isometric strength in a prone position using a force platform. However, this position may lack functional relevance, and the force platforms are not portable. A functional electromechanical dynamometer may provide a potentially valid, reliable, portable, and standardized seated alternative. Design : Randomized, repeated-measures design to assess the between-session reliability and concurrent validity of the Modified Seated ASH Test using an electromechanical dynamometer compared with the prone ASH test using a force platform. Methods : Thirty-four active university students (15 males, 19 females; 19.73 [3.68] years) completed ASH assessments using a force platform (prone) and an electromechanical dynamometer (seated). We evaluated between-session reliability using intraclass correlation coefficients and coefficients of variation and concurrent validity using Pearson correlations ( r ) and Bland–Altman analyses. Results : The electromechanical dynamometer demonstrated excellent reliability across the 180° (I), 135° (Y), and 90° (T) positions (intraclass correlation coefficient = .91–.97, coefficients of variation = 7.25%–11.33%). The force platform also showed good to excellent reliability but with higher variability (intraclass correlation coefficient = .83–.91, coefficients of variation = 12.43%–15.89%). Electromechanical dynamometer and force platform forces correlated strongly across positions ( r = .77–.87, P < .001). However, Bland–Altman analyses revealed the electromechanical dynamometer yielded systematically higher forces (bias = 18–28 N) with nontrivial limits of agreement, indicating scores differ meaningfully between devices. Conclusions : The Modified Seated ASH test, using an electromechanical dynamometer, has good to excellent reliability for assessing upper limb isometric strength and is strongly associated with the traditional force platform-based ASH test. The presence of systematic bias and nontrivial limits of agreement indicates that electromechanical dynamometer- and force platform-derived forces should not be considered interchangeable for absolute strength quantification.

El Programa Sport+EF: Balonmano Cognitivamente Enriquecido es una intervención extracurricular dirigida a estudiantes de 8 a 10 años, cuyo objetivo es mejorar las funciones ejecutivas (memoria de trabajo, inhibición, flexibilidad, planificación, toma de decisiones, anticipación, atención y autorregulación) mediante la práctica de balonmano con tareas diseñadas para aumentar la demanda cognitiva. El programa consta de 36 sesiones (3 por semana, durante 12 semanas), estructuradas en niveles progresivos (básico, medio y avanzado) y organizadas en cuatro fases: calentamiento, actividad principal, competición y vuelta a la calma con reflexión metacognitiva. Las actividades combinan habilidades motrices y cognitivas, adaptándose al nivel del grupo y promoviendo la variabilidad, la resolución de problemas y la interacción social. La implementación requiere un docente de educación física con experiencia en infancia y considera normas de seguridad y materiales adaptados. Se evalúan habilidades motrices y cognitivas a lo largo del programa. Se espera un impacto positivo en el desarrollo integral de los estudiantes, potenciando tanto el rendimiento motor como el cognitivo y socioemocional.

Background: Determining the reliability of exercise instruments and protocols in the fields of health and sports performance is of great interest due to their close relationship with monitoring and decision-making in athletes. Studies in trained women are limited, and more evidence is needed on performance variables and the reliability of exercise protocols. Objective: This study aimed to evaluate the reliability of an exercise protocol for determining mean muscle strength, mean velocity, and mean power during the bilateral standing press (BSP) in trained women. Methods: Sixteen trained women (age = 20.0 ± 2.30 years; body mass = 67.63 ± 6.68 kg; height = 1.65 ± 0.06 m) participated in this repeated-measures study. Absolute reliability was assessed using the coefficient of variation (CV), and relative reliability was assessed using the intraclass correlation coefficient (ICC) for a bilateral standing press (BSP) exercise protocol performed at intensities of 30% and 60% of isometric peak force (IPF). Results: Mean muscle strength showed acceptable absolute reliability and extremely high relative reliability at both 30% IPF (CV = 6.51%; ICC = 0.94) and 60% IPF (CV = 5.03%; ICC = 0.97). Mean velocity showed extremely high relative reliability at 60% IPF (ICC = 0.92), but its absolute reliability was not acceptable at either 30% IPF (CV = 10.10%; ICC = 0.75) or 60% IPF (CV = 14.16%; ICC = 0.92). Mean power also exceeded the predefined CV threshold at 30% IPF (CV = 11.16%; ICC = 0.85) and at 60% IPF (CV = 14.35%; ICC = 0.89). Conclusions: These findings suggest that the BSP protocol using functional electromechanical dynamometry is reliable for assessing mean muscle strength in trained women. However, mean velocity and mean power should be interpreted with caution, as their absolute reliability did not reach the predefined threshold of acceptable reliability.

Background: Lepidium meyenii Walp (L. meyenii), traditionally known as maca, is widely recognized for its health-promoting properties, including potential protection against exercise-induced muscle damage (EIMD). However, its precise effect on post-exercise blood biomarkers remains unclear. Objective: This study aimed to qualitatively review research published until April 2026 examining L. meyenii supplementation to reduce blood markers of muscle damage and protein degradation post-exertion in animal studies. Specifically, the effect size (ES) of L. meyenii supplementation on post-exercise levels of creatine kinase (CK), lactate dehydrogenase (LDH), and blood urea nitrogen (BUN) was estimated. Methods: This systematic review and meta-analysis were conducted in accordance with the PRISMA guidelines. The certainty of the evidence was assessed using the GRADE framework. Relevant studies were identified through Web of Science, Scopus, SPORTDiscus, PubMed, and MEDLINE. Eligible studies included in vivo experiments in animals with controlled designs and pre-/post-intervention assessments. Methodological quality and risk of bias were evaluated using the CAMARADES tool. Statistical analysis involved standardized mean differences (SMD) using Hedges’ g with 95% confidence intervals. Results: 15 studies were included in the systematic review, and 14 studies in animals in the meta-analysis. The CAMARADES scores ranged from 5 to 7 points, indicating moderate methodological quality. Supplementation with L. meyenii was not associated with statistically significant changes in LDH (SMD = −1.37; 95% CI −3.34 to 0.59), BUN (SMD = −0.37; 95% CI −2.16 to 1.42) nor CK (SMD = 0.29; 95% CI −5.45 to 6.03), with very high heterogeneity (I² > 97%). Exploratory subgroup analyses and meta-regression analyses by formulation type and dose did not identify any moderators that could robustly explain this heterogeneity. Conclusions: The available evidence does not support a robust overall effect of L. meyenii supplementation on blood biomarkers of muscle damage or protein catabolism in animals subjected to physical stress. The high degree of heterogeneity could not be robustly explained by either the type of formulation or the dose. These findings, which are exploratory and hypothesis-generating in nature, highlight the need for standardized, well-characterized formulations and trials with adequate statistical power.

Background/Objectives: Frailty and functional decline represent major challenges for aging populations, particularly among institutionalized older adults. Preserving functional capacity is essential to maintain autonomy, mobility, and quality of life. This study aimed to compare the effects of two strength training interventions—functional electromechanical dynamometer (FEMD) training and weighted vest training—on peak concentric and eccentric force during the sit-to-stand task, as well as on functional performance and body composition in frail nursing home residents. Methods: A pilot quasi-experimental study with a non-randomized control group was conducted in 19 older adults (mean age: 86.3 ± 5.8 years). Participants were allocated to FEMD training (EG1, n = 6), weighted vest training (EG2, n = 6), or a control group (CG, n = 7). Training was performed twice weekly for eight weeks. Assessments included body composition, handgrip strength, 30 s chair stand test, 3 m walking speed, and peak concentric and eccentric force during the sit-to-stand movement. Data were analyzed using mixed-model ANOVA and complementary within-group analyses. Results: No significant group × moment interactions were observed. However, EG1 demonstrated significant within-group improvements in chair stand performance (+4.8 repetitions, p = 0.006), walking speed (+0.1 m·s⁻¹, p = 0.030), concentric peak force (+46.5%, p = 0.008), and eccentric peak force (+34%, p = 0.047). EG2 showed a smaller but significant increase in eccentric peak force (+6.1%, p = 0.019), without functional improvements. Body composition changes were modest, with EG1 showing increases in weight and BMI without concomitant fat mass gains. Conclusions: In this pilot quasi-experimental study, functional electromechanical dynamometer-based training was associated with improvements in neuromuscular performance, particularly concentric peak force. However, no significant group × moment interactions were observed, indicating that differential effects between interventions cannot be established. Functional improvements should be interpreted cautiously. The present results should therefore be considered exploratory and hypothesis-generating. These findings suggest that FEMD-based training may be a feasible and potentially beneficial functional strength training strategy for frail institutionalized older adults, which should be confirmed in adequately powered randomized controlled trials.

The aim of this review was to evaluate the impact of strength training on hamstring muscle strength and physical performance in football players. A systematic review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, and the protocol was registered in PROSPERO. A literature search was performed using four electronic databases, such as Web of Science, SCOPUS, SportDiscuss, and PubMed. Randomized controlled trials conducted with football players aged 15 years or older were included. The studies were grouped according to moderating variables such as training protocol and physical performance outcomes. A total of 20 studies met the inclusion criteria for this review, with 10 studies included in the meta-analysis. Strength training programs demonstrated moderate to large effects on both concentric and eccentric strength of the hamstrings and quadriceps, as well as on physical performance measures such as jumping and sprinting. Eccentric overload training produced the most significant benefits in sprint and jump performance. Strength training, particularly eccentric training, significantly improves both the hamstring muscle strength and the physical performance in male football players aged 15 years and older, highlighting its importance for injury prevention and sport performance enhancement. However, additional research is needed to evaluate whether similar benefits can be observed in female players and younger age groups.

Background: Muscle strength asymmetries between limbs are common in physically active populations and may influence performance and injury risk. This study aimed to: (i) analyze the reliability of the seated unilateral cable row exercise using a functional electromechanical dynamometer (FEMD) and to examine differences in reliability between sides and contraction types; (ii) investigate the relationship between the dominant and non-dominant sides, as well as between the dynamic and static force production of the back muscles; and (iii) quantify force output and assess interlimb asymmetries. Methods: Twenty-nine young physically active athletes completed two sets of four repetitions of a seated unilateral cable row at 0.30 m·s⁻¹ using the FEMD, followed by a 6-s isometric contraction. Two testing sessions were conducted seven days apart. Reliability was assessed using paired t-tests, the effect size, the coefficient of variation (CV), the standard error of measurement, and the intraclass correlation coefficient (ICC), with 95% confidence intervals. Results: Peak and average force values showed very high to extremely high relative reliability (ICC = 0.86–0.96) and acceptable absolute reliability (CV ≈ 10%). Differences between dominant and non-dominant sides varied depending on contraction type. While group-level asymmetries did not exceed 10%, individual analysis revealed that 14%, 32%, and 7% of participants had asymmetries greater than 15% in isometric, concentric, and eccentric force, respectively. Conclusions: This test demonstrates strong reliability and provides a practical method for assessing upper limb asymmetries in physically active individuals, with potential applications in performance monitoring and injury prevention.

Purpose: We aimed to analyze the intra-set reliability of 5 sit-to-stand (5-STS) exercises with a functional electromechanical dynamometer (FEMD) and to determine and compare the load-velocity (L-V) profile in the STS exercise in adult pediatric cancer survivors by sex, age, body mass index, and type and treatment of cancer. Method: A total of 47 participants performed the 5-STS test with 5% and 20% body weight (BW) to assess intrasession reliability and analyze differences in L-V profiles by sex, age, BMI, and type and treatment of cancer. Results: Very high and extremely high relative reliability was found for both the 5% STS (ICC = 0.80–0.94) and the 20% STS (ICC = 0.87–0.95) relate to average and peak force, power, and velocity. Regarding L-V profiles, significant differences were only found in relation to sex for the velocity-axis intercept and area under the line (p < 0.05). Conclusion: The 5-STS test with a load of 5% and 20% of BW using a FEMD is a reliable method for assessing strength, power, and velocity exercise in adult pediatric cancer survivors. There was a relation to sex for the variables of L-V profile. Implications for cancer survivors: Reliable assessments of muscular strength, like the 5-STS test using FEMD, offer a safer, less demanding alternative to maximal strength tests (e.g., 1RM), enabling precise intensity control and better-tailored rehabilitation programs.

The application of blood flow restriction (BFR) during resistance exercise enhances muscular adaptations under low-load conditions. However, its acute effects on explosive neuromuscular performance, particularly on kinetic variables such as the rate of force development (RFD), impulse, and peak force remain poorly understood in women. Twenty-five participants underwent randomized sessions under three occlusion conditions (0%, 40%, and 80% limb occlusion pressure), followed by isometric mid-thigh pull (IMTP) assessments at five time points (pre-exercise; post-exercise; and 5, 10, and 15 min post-exercise). Peak force, impulse, and RFD were analyzed across early (0–50 ms), mid (51–150 ms), and late (151–250 ms) time intervals. BFR did not result in statistically significant alterations in RFD or isometric force production at any time or pressure. These findings indicate that acute BFR application, even when volitional fatigue is induced, does not substantially impair neuromuscular function in isometric settings. These findings indicate that acute exposure to BFR, even under fatiguing conditions, does not substantially impair isometric force production or explosive performance in young physically active women. These results support the task-specific and temporally dependent nature of neuromuscular responses to BFR, highlighting the need for population-specific approaches in BFR programming.

The peak velocity of an athlete’s throws is a determining factor for sports performance. The aim of this study was to analyze the effects of a post-activation performance enhancement (PAPE) protocol with functional electro-mechanical dynamometry (FEMD) on throwing velocity. Thirteen international-level female handball players voluntarily participated in the study. The PAPE protocol considered four sets of eight repetitions controlled by FEMD (four at 30% of 1RM followed by another four at 60% of 1RM). After each series, the athletes’ throwing velocity was measured. Significant differences (p < 0.01) were found in the effect size (ES), which measures the strength of the statistical relationship between two variables by group with the repeated measures ANOVA statistic with an effect size ω² = 0.028. The effect size analysis identified measurements that are considered null for the baseline—PAPE 1 comparison and small baseline—PAPE 2, baseline—PAPE 3, and baseline—PAPE 4. When resistance is controlled during the run as with an FEMD device, only two sets of eight repetitions (four repetitions at 30% and four repetitions at 60% of 1RM) are required for the improvement of throwing speed in elite handball players.