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Background: Type 2 diabetes mellitus is a metabolic disorder characterized by insulin resistance (IR), which is prevalent worldwide and has significant adverse health effects. Metformin is commonly prescribed as a pharmacological treatment. Physical exercise is also recognized as an effective regulator of glycemia, independent of metformin. However, the effects of inter-day concurrent training (CT)—which includes both endurance and resistance exercises—combined with metformin treatment on metabolic markers and cardiorespiratory fitness in individuals with IR remain controversial. Objective: This study aimed to analyze the effects of a 12-week inter-day CT program on metabolic markers and cardiorespiratory fitness in overweight/obese individuals with IR, both with and without metformin treatment. Additionally, inter-individual responses to CT were examined. Materials and Methods: Data from the 2022–2023 Obesity Center database were retrospectively analyzed. According to the eligibility criteria, 20 overweight/obese individuals diagnosed with IR participated in a 12-week CT program (three weekly sessions: two endurance and one resistance exercise session). Participants were divided into three groups: the exercise group (E-G: n = 7, 32.86 ± 8.32 years, 85.2 ± 19.67 kg), the exercise–metformin group (E-MG: n = 6, 34.83 ± 12.91 years, 88.13 ± 12.66 kg), and the metformin-only control group (M-G: n = 7, 34.43 ± 13.96 years, 94.23 ± 13.93 kg). The M-G did not perform physical exercise during the 12 weeks but continued pharmacological treatment. Body composition, metabolic markers, and cardiorespiratory fitness were assessed before and after the 12-week CT program. Results: A group-by-time interaction was observed for fasting insulin (F2,17 = 34.059, p < 0.001, η2p = 0.88), the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (F2,17 = 35.597, p < 0.001, η2p = 0.80), and maximal fat oxidation (MFO) (F2,17 = 4.541, p = 0.026, η2p = 0.348) following the CT program. The maximal oxygen uptake (VO2max) showed significant improvements in the E-G (F = 4.888, p = 0.041, ∆+13.3%). Additionally, the percentage of fat mass (%FM) and body mass (BM) were significantly reduced across all groups (F = 125.244, p < 0.001 and F = 91.130, p < 0.001, respectively). The BM decreased by ∆−9.43% in the E-G (five responders, Rs), ∆+9.21% in the EM-G (5 Rs), and ∆+5.15% in the M-G (3 Rs). The %FM was reduced in the E-G by ∆−22.52% (seven Rs). Fasting insulin and the HOMA-IR significantly improved in both the E-G and EM-G, with fasting insulin showing a ∆−82.1% reduction in the E-G (five Rs) and a ∆−85% reduction in the EM-G (six Rs). Similarly, the HOMA-IR improved by ∆+82.6% in the E-G (three Rs) and by ∆+84.6% in the EM-G (six Rs). Conclusions: The 12-week inter-day concurrent training program, whether combined with metformin or not, was similarly effective in improving metabolic markers in patients with insulin resistance as metformin treatment alone. Both exercise groups demonstrated a significant reduction in insulin sensitivity and an increase in maximal fat oxidation. Meanwhile, exclusive pharmacological treatment with metformin markedly decreased cardiorespiratory fitness, and consequently, fat oxidation. [ABSTRACT FROM AUTHOR]

Featured Application: It is possible to improve punches' impact force both chronically and acutely. Before fights or sparring sessions, maximal isometric exercises can be integrated with punching techniques (e.g., three repetitions of 3 s), resistance band exercises with punching techniques (e.g., two sets of 5 reps), medicine ball throws with 10% of 5RM bench press (e.g., three sets of 8 reps), SJ with 30% of 1RM (e.g., four sets of 8 reps) and traditional exercises such as bench press and back squat with 80% of 1RM (e.g., three sets of 5 reps) with an improvement window in punches' impact force between 6 and 15 min after the exercises. The aim of this scoping review was to compile the current evidence and provide a summary of the acute and chronic effects of muscle strength training on the physical fitness of amateur boxers and provide recommendations to optimize their physical performance. This scoping review was developed using guidance from the Joanna Briggs Institute and PRISMA-ScR. The search was conducted in the Scopus, PubMed and Web of Science databases between December 2023 and June 2024. In total, 50 full-text articles were assessed to determine eligibility, while 15 studies met the inclusion criteria and were subjected to detailed analysis and assessment of their methodological quality. Our findings indicate that muscular strength training interventions can improve punching performance in amateur boxers acutely and chronically, in addition to improving their physical fitness and generating increases in the capacity to generate maximum force and improvements in RFD and the power production of the upper and lower limbs of boxers. However, this scoping review only included one study in female boxers, so we recommend that future studies contain muscular strength training interventions in females to analyze their adaptations in punching force and physical fitness. [ABSTRACT FROM AUTHOR]

ResumenEste estudio pretende analizar si existe pérdida en la consistencia de la técnica especial en Judo cuando se ven comprometidas las reservas energéticas del judoka, y si existen, conocer cuáles son los elementos más significativos que pudieran condicionar la óptima ejecución del mismo. Los combates de Judo suelen terminar con una tasa de acumulación lactácida de entre 14 a 20 mmol/l en sangre. El test utilizado (COPTEST©) reproduce un combate de Judo con altos niveles de solicitación anaeróbica que asemejan los requerimientos energéticos de un combate en el contexto de la alta competición. En los últimos años, varios estudios científicos (Sterkowicz,1999,2002), (García 1996,1999,2004), (Monteiro, 2003), (Francini, 2003) han intentado enumerar los posibles aspectos tanto condicionales como técnicos y cognitivos que diferencian a un judoka campeón de otro que no lo es. Método: Utilizando el modelo de investigación del paradigma Experto-Novato de Shulman (1986) se evaluaron 110 judokas de alto rendimiento. Todos realizaron el Coptest (García, 1995). Se consideraron “expertos” a los judokas que habían obtenido medalla en unos JJOO, cto mundial o cto continental. Eran “novatos” los judokas de alto rendimiento que no habían conseguido tal resultado. Se evaluaron las siguientes variables: a) Desequilibrio b) adecuación secuencial c) ángulo requerido para la correcta construcción de la técnica y d) elementos determinantes para que exista proyección Se tomaron datos de todas la ejecuciones del Tokui waza durante la ejecución del Coptest (total 4950 proyecciones). El análisis de los datos reveló que existen diferencias significativas en la ejecución del tokui waza realizado por un judoka “experto” al realizado por uno “novato.AbstractThe aim of this study tries to analyze if loss in the consistency of the special technique in Judo exists when are seen it jeopardize the power reserves of judoka and know which are the most significant elements that they could condition the optimal execution of he himself. In recent years, various scientific studies (Sterkowicz,1999, 2002), (García 1996,1999,2004), (Monteiro, 2003), (Francini,2003) have tried to establish the possible different conditional, technical and cognitive aspects that differentiate one judo champion from another, although possessing in principle the necessary technical condition to be a champion but not being capable of climbing to the top of the podium. Method: Using the investigation model of the paradigm Expert-Novice of Shulman (1986) 110 high performance judokas were evaluated. All carried out the Coptest (García,1995). “Experts” are considered to be those judokas who have won a medal at Olympic, World or Continental Championships. “Novices” are considered to be those high performance judokas who have not achieved the results mentioned before. The following variables were evaluated: a) Lack of Equilibrium, b) Sequential Technical Performance, c)The required angle for the correct construction of the Technique and d)Determining elements so that projection exists. The analysis of the data showed that there were significant differences between the execution of Tokui Waza performed by an “expert” judoka and that performed by a “novice”.

The aim of this study was to determine body composition influence on cardiorespiratory fitness and metabolic markers in physically inactive individuals with insulin resistance (IR). Nineteen overweight and obese (body mass index [BMI] 25.0–29.9 kg·m−2; ≥ 30.0 kg·m−2, respectively) patients diagnosed with IR (5 men and 14 women; age: 32.74 ± 10.07 years; BMI: 32.5 ± 4.60 kg·m−2). The body composition included BMI, fat mass, and fat-free mass. Cardiorespiratory fitness was measured by maximal oxygen uptake (VO2max). Metabolic markers included maximal fat oxidation, fasting glucose, and insulin. IR was determined by homeostatic model assessment (HOMA-IR). The results of the partial correlations (i.e., body mass, age, and sex) reported that fat-free mass, fat mass, and BMI were significantly correlated with VO2max. Additionally, the multiple linear regression model indicated that fat-free mass and BMI explained the variance of VO2max by 89%. However, no substantial correlations were reported between fat mass or fat-free mass with HOMA-IR, fasting glucose, or insulin. This study concluded that a higher percentage of fat-free mass and lower BMI is positively related to better cardiorespiratory fitness despite the IR status of the participants analyzed. [ABSTRACT FROM AUTHOR]

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BACKGROUND: In taekwondo the ability to repeat high-intensity efforts is characteristic of the sport. The Frequency speed of kick test (FSKT) is frequently used to assess this ability, although its influence on aerobic capacity and dynamic strength characteristics has received less attention in the literature. OBJECTIVE: To examine the relationship between specific high-intensity intermittent efforts with aerobic capacity and slow stretch-shortening cycle utilization in taekwondo athletes. METHODS: Nineteen taekwondo male athletes were assessed by squat jump (SJ), countermovement jump (CMJ), 20-meter shuttle run (20MSR), and frequency speed of kick test multiple (FSKT MULT). From the FSKT MULT , total kicks and kick decrement index [KDI] were calculated. Additionally, from both jump tests, the slow stretch-shortening cycle utilization (Slow SSC Utilization) was determined from the eccentric utilization ratio [EUR], pre-stretch augmentation [PSA], and reactive strength index [RSI]. RESULTS: There were positive and significant correlations between total kicks with 20MSR (r = 0.85; p = 0.00) and SJ (r = 0.66; p < 0.05). The multiple regression model demonstrated that total kicks where significantly influenced by 20MSR ( R 2 = 71%; p = 0.00). Additionally, only EUR and RSI explained total kicks performance to a greater proportion ( R 2 = 76%). CONCLUSIONS: The FSKT MULT total kicks performance is positively correlated and influenced by aerobic capacity and slow SSC utilization. [ABSTRACT FROM AUTHOR]

BACKGROUND: Explosive strength and change of direction speed (CODS) are relevant physical abilities in karate. OBJECTIVE: To examine the relationship between the characteristics of explosive strength and the 5-m linear sprint (5M) with CODS performance and ii) to examine the influential characteristics of explosive strength on CODS performance. METHODS: Eighteen cadet and junior karate athletes, eight females and ten males were evaluated. The physical abilities assessments included: squat jump (SJ), countermovement jump (CMJ), 5M and CODS. Also, pre-stretch percentage increase (PSA), eccentric utilization index (EUR) reactive strength index (RSI) were calculated. RESULTS: Superior performance (p < 0.05) was documented in SJ, CMJ and CODS in male vs. female. Also, significant correlations between CODS with SJ and CMJ (r = - 0.70 to - 0.80; R 2 = - 0.51 to - 0.73; p < 0.05, respectively) and correlations (r = - 0.14 to - 0.22; R 2 = 0.01 to 0.04; p > 0.05) between CODS with RSI, EUR and PSA. Multiple regression model documented that only SJ significantly influenced CODS performance in male ( R 2 = 60%; p = 0.009) and female ( R 2 = 71%; p = 0.001). CONCLUSION: CODS correlate with SJ and CMJ. In particular, SJ influence CODS independently of gender. [ABSTRACT FROM AUTHOR]

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This study investigated the effect of 4weeks of high-intensity interval training (HIIT) with specific techniques and analyzed inter-individual variability [classified in responders (Rs) and non-responders (NRs)] on jumping ability and change of direction speed (CODS) in youth karate athletes. Athletes of both genders (n =10) were randomly assigned into experimental group (EG; n =5) and the control group (CG; n =5). The EG trained 2–3days per week applying HIIT (three rounds [15 sets of 4s all-out specific efforts with 8s of dynamical pauses] with 3min of recovery between rounds) during their usual training during 4weeks. Assessments included squat jump (SJ) and countermovement jump (CMJ) and CODS by T-test. No significant interaction effect group by time was found. Although, in percentage and effect size (ES) terms increases were reported in both groups for SJ (EG: 15.2%, ES=0.91 vs. CG: 12.4%, ES=0.02) and only in EG for the T-test (−1.7%; ES=−0.35). In turn, a trend toward a higher proportion of Rs was observed in the EG (40% Rs) vs. CG (20% Rs) for SJ and CODS, respectively. In conclusion, the addition to regular training of a HIIT with specific techniques and based on the temporal combat structure after 4weeks was not a sufficient stimulus to increase jumping ability and CODS in karate athletes. [ABSTRACT FROM AUTHOR]

This study investigated the effect of 4 weeks of high-intensity interval training (HIIT) with specific techniques (TS-G) vs. repeated sprints (RS-G) and analyzed the inter-individual variability [classified into responders (Rs) and non-responders (NRs)] on sport-related fitness in taekwondo (TKD) athletes. Athletes of both genders (n = 12) were randomly assigned into TS-G and RS-G groups. Both groups trained 3 days/week for 4 weeks [two blocks of three rounds of 2 min of activity (4-s of all-out efforts with 28-s dynamical pauses) with 1 min of recovery in between and 5 min between blocks] during their regular training. The related sport fitness assessments included squat jump (SJ), countermovement jump (CMJ), multiple frequency speed of kick test (FSKTMULT), specifically total kicks and Kick Decrement Index (KDI), and 20-m shuttle run (20MSR). Relevant results indicate a significant effect of the time factor in both groups for SJ performance and a significant decrease for KDI in RS-G. In addition, an improvement in performance according to the effect size analysis in the TS-G in total kicks, KDI, and 20MSR. Complementarily, a higher proportion of athlete Rs was reported in TS-G vs. RS-G for SJ (50% vs. 30.3%, respectively), CMJ, and total kicks (16.6% vs. 0%). In conclusion, the addition to the regular training of a HIIT with specific-techniques and repeated-sprints associated with intervals and similar structure of the combat during 4 weeks of training can improve the concentric characteristics of lower limb performance, although they were not the sufficient stimuli in the other components of TKD-related fitness. [ABSTRACT FROM AUTHOR]

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Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gold nanoparticles (AuNPs) are functionalized with a thermoresponsive polymer shell of a cross-linked poly(2-(2-methoxyethoxy)ethyl methacrylate) (P(MEO2MA)). To provide a covalent attachment of the polymer to the NP surface, AuNPs are first modified using butanoic acid to develop the encapsulation with the biocompatible thermoresponsive polymer formed by free-radical precipitation polymerization. Both the MEO2MA concentration and the shell cross-linking density can be varied and, in turn, the thickness and the shells' free volume can be fine-tuned. By downscaling the size of the polymeric shell, the lower critical solution temperature (LCST) is decreased. The LCST in the nanohybrids changes from 19.1 to 25.6 °C when increasing the MEO2MA content; it reaches almost 26 °C for P(MEO2MA) (bulk). The maximum decrease in the volume of the nanohybrids is around 40%, resulting in a modification of the light scattering properties of the system and causing a change in the turbidity of the gel network. The sizes of the nanohybrids are characterized using both transmission electron microscopy and dynamic light scattering measurements. Optical properties of the colloidal systems are determined using the derived count rate measurements as an alternative to absorbance or transmittance measurements, confirming the colloidal stability of the nanohybrid systems. [ABSTRACT FROM AUTHOR]

Copyright of Revista Iberoamericana de Ciencias de la Actividad Física y el Deporte is the property of Revista Iberoamericana de Ciencias de la Actividad Física y el Deporte and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)