The aim of this research was to compare the effects of a technique-specific high-intensity interval training (HIIT) protocol vs. traditional taekwondo training on physical fitness and body composition in taekwondo athletes, as well as to analyse the inter-individual response. Utilising a parallel controlled design, sixteen male and female athletes (five females and 11 males) were randomly divided into an experimental group (EG) that participated in the technique-specific HIIT and a control group (CG) that participated in traditional taekwondo training. Both groups trained three days/week for four weeks. Squat jump (SJ), countermovement jump (CMJ), 5-metre sprint (5M), 20-metre shuttle run (20MSR), taekwondo specific agility test (TSAT), multiple frequency speed of kick test (FSKT_MULT), total kicks, and kick decrement index (KDI), as well as body composition were evaluated. Results indicate that there are no significant differences (p > 0.05) in the factors group and time factor and group by time interaction (p > 0.05). Although percentage and effect size increases were documented for post-intervention fitness components in TSAT, total kicks, KDI, and 20MSR, responders and non-responders were also documented. In conclusion, a HIIT protocol based on taekwondo-specific technical movements does not report significant differences in fitness and body composition compared to traditional taekwondo training, nor inter-individual differences between athletes.

Judo is a sport that requires multiple high-intensity moments during the fight and high neuromuscular performance. Although not often, the explosive actions of the lower limbs can be decisive to winning in combat. This study aims to identify the differences in the neuromuscular features of the range of movements of the upper and lower limbs between the top-elite and elite male judo athletes. This cross-sectional study included 63 high-level male judo athletes, who were classified into two level groups: (i) top-elite (n = 30; age: 23.5 ± 3.2 years) and (ii) elite (n = 33; age: 22.6 ± 2.9 years). All the participants went to the laboratory for neuromuscular evaluations in the bench press (BP), prone row (PR), and repeated jump in 30 s (RJ30) tests. The results show that the top-elite judo athletes are superior in all the upper-body neuromuscular attributes studied. These differences were significantly superior in (i) BP peak velocity (p < 0.01), maximum load 1RM, power (peak and mean), force (peak and mean), force mean to peak power, and rate of force development (RFD) (all, p < 0.001); and (ii) RP maximum load 1RM (p < 0.01), power load (kg, p < 0.001; % 1RM, p < 0.05), peak power (p = 0.010), power mean (absolute, p < 0.01; relative, p < 0.05), force mean (p < 0.05), force mean to peak power (absolute, p < 0.05) and RFD (p < 0.001). However, no significant differences were observed in the BP and PR time to peak force, time to peak power, and time between peaks (power and force). In the RJ30, it was observed that the initial contact time (T1) of top-elite athletes is significantly lower than that of elite athletes (p < 0.05) and that power at 15 (T2) and 30 (T3) seconds is significantly higher in top-elite athletes (T2, p < 0.05; T3, p < 0.01). The main effect of the performance group was significant in contact time (p < 0.05), and the main effect of time was statistically significant in jump height (p < 0.001), power (p < 0.001), force (p < 0.001) and velocity (p < 0.01). In addition, jump height (p < 0.01; η²_p = 0.088) and power (p < 0.05; η²_p = 0.068) showed a significant interaction between time and performance group. These results suggested that the observed superiority of the top-elite judo athletes in neuromuscular attributes can determine success in judo competitions. This observation reinforces that neural and metabolic profiles must be considered to increase the effectiveness of maximal power training for the upper and lower body.

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.

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 (F_2,17 = 34.059, p < 0.001, η²_p = 0.88), the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (F_2,17 = 35.597, p < 0.001, η²_p = 0.80), and maximal fat oxidation (MFO) (F_2,17 = 4.541, p = 0.026, η²_p = 0.348) following the CT program. The maximal oxygen uptake (VO2_max) 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.

Objective: This study aimed to identify the effects of a submaximal jump training program using accentuated eccentric loading (AEL) on punching performance and countermovement jump (CMJ) force–time characteristics in amateur boxers. Methods: Twenty-nine amateur boxers (age: 24.9 ± 5.4 years; height of 175.9 ± 5.2 cm; body mass: 76.2 ± 10.5 kg) were randomly assigned to three groups: AEL group (n = 9), CMJ group (n = 10), and control group (n = 10). The AEL group performed countermovement jumps using handheld dumbbells equivalent to 10–20% of body mass, followed by unloaded concentric phases. All participants were evaluated pre- and post-intervention on punching peak force and countermovement jump performance. Results: Significant differences were found in favor of the AEL group for the peak force of the jab punch (pre: 1050 ± 203; post: 1158 ± 189 N), straight punch (pre: 1685 ± 393; post: 1861 ± 429 N), right cross punch (pre: 2005 ± 362; post: 2150 ± 417 N), and left cross punch (pre: 1836 ± 312; post: 1977 ± 393 N), along with greater gains in jump height, propulsive impulse, and absolute and relative peak power than the CMJ and control groups. Conclusions: A submaximal accentuated eccentric jump training program enhances punching peak force and lower-limb power output in amateur boxers, offering a practical strategy for improving power-oriented performance during preparatory training phases.

Metformin, a drug widely used to treat insulin resistance, and training that combines aerobic and strength exercise modalities (i.e., concurrent training) may improve insulin sensitivity. However, there is a paucity of clinical trials investigating the effects of concurrent training, particularly on insulin resistance and fat oxidation in overweight and obese patients. Furthermore, only a few studies have compared the effects of concurrent training with metformin treatment. Therefore, the aim of this study was to examine the effects of a 12-week concurrent training program versus pharmaceutical treatment with metformin on maximum fat oxidation, glucose metabolism, and insulin resistance in overweight or obese adult patients. Male and female patients with insulin resistance were allocated by convenience to a concurrent training group (n = 7 (2 males); age = 32.9 ± 8.3 years; body mass index = 30 ± 4.0 kg·m⁻²) or a metformin group (n = 7 (2 males); age = 34.4 ± 14.0 years; body mass index = 34.4 ± 6.0 kg·m⁻²). Before and after the interventions, all participants were assessed for total body mass, body mass index, fat mass, fat-free mass, maximum oxygen consumption, maximal fat oxidization during exercise, fasting glucose, and insulin resistance through the homeostatic model assessment (HOMA-IR). Due to non-normal distribution of the variable maximal fat oxidation, the Mann–Whitney U test was applied and revealed better maximal fat oxidization (Δ = 308%) in the exercise compared with the metformin group (Δ = −30.3%; p = 0.035). All other outcome variables were normally distributed, and significant group-by-time interactions were found for HOMA-IR (p < 0.001, Δ = −84.5%), fasting insulin (p < 0.001, Δ = −84.6%), and increased maximum oxygen consumption (p = 0.046, Δ = 12.3%) in favor of the exercise group. Similar changes were found in both groups for the remaining dependent variables. Concurrent training seems to be more effective compared with pharmaceutical metformin treatment to improve insulin resistance and fat oxidation in overweight and obese adult patients with insulin resistance. The rather small sample size calls for more research in this area.