Search

This study measured the effect of caffeine on brown adipose tissue (BAT) activity and the energy expenditure (EE) of subjects with high (HBAT) or low (LBAT) activation. We performed a quasi-experimental double-blind protocol in which 24 physically active healthy men were measured (age: 24.1 ± 6.0 yrs; BM: 75.3 ± 14.4 kg; HT: 171.8 ± 5.9 cm; BMI: 25.5 ± 4.9 kg/m2). Infrared thermography (IRT) protocol was used to separate the participants into the groups according to the BAT activation: high (HBAT; n = 11) and low (LBAT; n = 13). All participants ingested a single supplement caffeine capsule (CAF) of 375 mg (~5 mg/kg BM) or placebo (PLA). Our experimental protocol measured two groups (HBAT and LBAT) under two conditions (CAF and PLA), with intake 30-min before the data collection. BAT activity lasted 60-min (0, 10, 20, 30, 40, 50, 60 min) and was estimated by IRT in subclavicular (Δ SCV) and external (Δ EXT) regions of interest (ROI) and EE by indirect calorimetry. The main results indicated that HBAT at 40-min showed an increased EE versus the other groups and conditions (p = 0.009). There was a significant difference for BAT activation at the 30 (p = 0.019), 40 (p = 0.009), 50 (p = 0.007) and 60 min (p = 0.012) between HBAT-CAF vs. LBAT-CAF. There was also a significant difference at the 20 (p = 0.024), 30 (p = 0.036), 50 (p = 0.05) and 60 min (p = 0.011) between HBAT-CAF vs. HBAT-PLA. In conclusion CAF intake (≈5 mg) increases the thermogenic activity of BAT in healthy young men and increases EE in HBAT subjects. • Caffeine intake induces acute thermogenic brown adipose tissue activity in healthy active young men. • Caffeine increases the energy expenditure in High brown adipose tissue subjects. • The main effects of caffeine in brown adipose tissue activity were observed after 30 min. [ABSTRACT FROM AUTHOR]

Background: Speed training with resisted sprints has been shown to positively affect neuromuscular performance in soccer players. Various loads, ranging from 10% to 120% of body mass, have demonstrated performance improvements across the spectrum. However, the impact of sprint distance with optimal load on these adaptive responses has yet to be thoroughly described., Objective: To analyze the influence of sprint distance in resisted sprints on muscle performance in young soccer players., Methods: This quantitative study utilized a pre-post experimental design. The sample consisted of 24 young soccer players (15.3 ± 0.68 years; 61.4 ± 7.08 kg; 1.60 ± 0.06 m) randomized into three groups (10, 20, and 30 m) and subjected to 12 sessions of resisted sprint training over six weeks. The volume was homogenized across groups, with a total distance of 120 m for each. The intervention's effect was analyzed through performance in the isometric mid-thigh pull (IMTP), countermovement jump (CMJ), modified 505 agility test (505 m), and linear sprint tests. Differences were analyzed using a mixed ANOVA, incorporating a between-subjects factor (training group) and a within-subjects factor (pre- and post-intervention)., Results: Time-dependent differences were observed in all groups for peak force (PF) ( p < 0.001; η 2 p = 0.62), time to PF (TPF) ( p < 0.001; η 2 p = 0.53), impulse at 50 ( p < 0.001; η 2 p = 0.57), 100 ( p < 0.001; η 2 p = 0.60), and 200 ms ( p < 0.001; η 2 p = 0.67) in IMTP; jump height by impulse-momentum ( p < 0.001; η 2 p = 0.64), rate of force development ( p = 0.04; η 2 p = 0.14), yielding impulse ( p < 0.001; η 2 p = 0.49), and concentric impulse ( p = 0.01; η 2 p = 0.19) in CMJ; time ( p < 0.001; η 2 p = 0.46) in 505 m; and average speed in linear sprint ( p = 0.003; η 2 p = 0.36), with moderate to large effect sizes, regardless of the distance covered. No differences were observed for the interaction between the time* and group or between groups., Conclusion: Performance improvements were independent of the sprint distance, with no differences between training groups. Distances between 10 and 30 m may enhance muscle performance in young soccer players.

(1) Background: The recovery method is important and decisive in the training system. This study aimed to assess the effects of various post-training recovery methods on muscle damage and strength indicators in Paralympic powerlifting athletes. (2) Methods: A crossover study was conducted involving eleven male athletes (25.4 ± 3.3 years, 70.3 ± 12.1 kg). Muscle damage was assessed using blood biochemical markers (cytokines IL-6, IL-10, and TNF-α) and isometric force indicators, including the maximum isometric force (MIF), time to MIF, and Rate of Force Development. The following assessments were performed before, immediately after, and at 24 and 48 h after the recovery protocol: (a) passive recovery (RP) or (b) cold-water immersion (CWI). (3) Results: The main results indicated that maximum isometric force (MIF) significantly improved after 48 h of CWI application ( p < 0.05; for all comparison). The analysis of biochemical markers did not yield significant differences between the recovery methods at different time points ( p > 0.05). For IL-6, there were significant differences between CWI before (2.29 ± 1.08, 95% CI 1.57-3.01) and CWI 2 h later (2 h) (4.59 ± 2.96, 95% CI 2.60-6.57; p = 0.045), and between CWI 15 min later (15 min) (4.14 ± 2.24, 95% CI 2.63-5.64) and CWI 48 h later (48 h) (2.33 ± 1.25, 95% CI 1.49-3.17; p = 0.034). There were differences between CWI 2 h (4.14 ± 2.24, 95% CI 2.63-5.64) and CWI 48 h later (2.33 ± 1.25, 95% CI 1.49-3.17; p = 0.035; F = 9.202; η 2 p = 0.479; high effect). (4) Conclusions: CWI significantly improved the post-resistance training muscle damage and strength in Paralympic powerlifting athletes.

Assessing the reliability of measurement instruments and equipment is essential to ensure the accurate tracking of athletes over extended periods, minimizing the measurement errors caused by chance or other factors. However, a less common but equally important analysis is the verification of inter-measurement agreement, which complements the reliability results. Purpose: To evaluate the intra- and inter-test reliability of an isometric hip adduction strength and asymmetries test in professional soccer players. Methods : Twenty-three professional male soccer players were evaluated on two occasions, 1 week apart. The force signal was collected using force plates (Pasco PS-2141), and the data processing was performed using Matlab software (R2023a, MathWorks, Natick, MA, USA). The peak force, interval RFD, peak RFD, peak force asymmetry and RFD were analyzed. Intraclass correlation coefficients (ICCs) and coefficients of variation (CV) were calculated to corroborate the intra- and inter-test reliability. In addition, the degree of agreement of the asymmetries was corroborated through the kappa index. Results : The peak force demonstrated an acceptable absolute reliability (CV < 10%) for the intra-test and test-retest condition, an excellent relative intra-test reliability and a good to moderate reliability for the test-retest reliability. However, the peak force asymmetry showed a moderate test-retest reliability and agreement. For the intra-test condition, the RFD variables demonstrate a moderate to excellent relative reliability; however, all demonstrate unacceptable absolute reliability (CV > 10%) in at least one of the evaluation sessions. A moderate to poor test-retest reliability and unacceptable absolute reliability were observed for all the RFD variables. Conclusions : The peak force is the variable with the highest intra- and inter-test reliability, so its use is recommended to longitudinally assess the maximum strength of the adductors in professional soccer players, but not the asymmetry orientation of the peak force. The RFD variables should be interpreted with caution due to their inconsistent reliability, and it is necessary to improve the methods used to achieve adequate reliability.

Several studies have shown that force application is influenced by different neuromuscular mechanisms depending on the time of force application analysis in isometric knee extension test (IKE), and a countermovement jump (CMJ) has contributions from knee extension, so some CMJ variables could be indicators of such mechanisms. Purpose: The aim of this study was to determine the level of relationship of variables of IKE and bilateral CMJ tests. Methods : Male college soccer players (n = 25; corporal mass = 72 ± 8 kg; height = 171 ± 5 cm; age = 22 ± 2 years) performed the IKE at two angles (60° and 75°) on an isokinetic machine and the CMJ on two uniaxial force platforms. To determine the level of relationship, Pearson's correlation coefficient was analyzed between the test variables. Results : Trivial to moderate correlations (r = -0.45 to 0.62; p < 0.05) were found between CMJ variables and IKE in both knee angles (60° and 75°); Conclusions : The variables of IKE have a trivial to moderate correlation with the variables of CMJ, so the variables of CMJ could not be considered interchangeably with those of IKE and therefore considered indicators of neuromuscular mechanisms isolated from the knee extensor function. Longitudinal design (fatigue or training protocols) should be realized to corroborate these results.

Sprint performance is a critical factor in soccer. While previous studies have extensively explored the biomechanical, physiological, and metabolic determinants of sprinting, the impact of anthropometric variables in team sports contexts, especially soccer, remains underexplored. This study aims to investigate the influence of anthropometric and mechanical variables on sprint performance in young soccer players. Fifty-eight young soccer players were evaluated in anthropometry and a 30-meter (m) sprint using radar technology. Split times in 5, 15, and 30 m were determined, in addition to the assessment of the force-velocity profile proposed by Morin and Samozino. Results: Key anthropometric variables associated with improved sprint performance included lower-limb muscle mass at distances 5 and 15 m ( R 2  = 0.08 and R 2  = 0.09, respectively, both with small effects). Additionally, body composition, particularly a lower % body fat, was crucial across all sprint distances (ES: large). Among the mechanical variables, max power ( R 2  = 0.997, ES: large) and maximum velocity ( R 2  = 0.553, ES: large) are the mechanical variables that were most strongly associated with sprint performance over distances greater than 30 m. Soccer coaches, athletic trainers, and strength and conditioning specialists working with young athletes can apply the findings of this study to their training programming., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Bustamante-Garrido, Aedo-Muñoz, Brito, Silva-Esparza, Pérez-Contreras, Izquierdo-Redin and Cerda-Kohler.)

Variable resistance training has been widely used in athletic preparation., Objectives: To analyze the use of currents (VRT) and the traditional method (TRAD) on speed, power and temperature in a training session., Methods: Fourteen paralympic powerlifting (PP) athletes took part over three weeks. In week 1, familiarization and 1RM tests took place, and, in weeks 2 and 3, pre- and post-training took place, where the propulsive mean velocity and power and temperatures were assessed before and after, at 24 h and 48 h., Results: There was a difference in the sternal pectoral temperatures before and after VRT ( p = 0.040) and at 48 h for TRAD and VRT ( p = 0.018); in the clavicular pectoralis before and after VRT and TRAD ( p = 0.003); in the anterior deltoid after and at 48 h for TRAD and VRT ( p = 0.026 and p = 0.017); and in the triceps after and at 24 h and 48 h between TRAD and VRT ( p = 0.005). In the training series, the MPV was significant in TRAD between Set1 and Set5 ( p = 0.003), in training (VRT) between Set1 and Set5 ( p = 0.001) and in Set5 between the methods ( p = 0.047). For power, there was a difference between Set1 and 5 in TRAD ( p = 0.016) and VRT ( p = 0.002)., Conclusion: We conclude that training with currents (VRT) promoted greater muscle fatigue when compared to traditional training.

This study delves into the intricate details of Mixed Martial Arts (MMA) by examining key variables such as maximal oxygen uptake (VO2 peak), aerobic energy (EAER), anaerobic energy (EAN), and accumulated O2 deficit (DOA). By investigating associations and comparing athletes in the -61 kg bantamweight and -66 kg featherweight weight divisions, we aim to shed light on their physiological characteristics. The sample consisted of 20 male volunteers separated into two paired groups: ten athletes in the category up to 61 kg (age: 27.7 ± 5.9 years old, height: 170.9 ± 3.4 cm, body mass: 72.8 ± 1.4 kg, fat percentage: 9.5% ± 3.0%, professional experience: 7.5 ± 7.1 years) and ten athletes up to 66 kg (age: 27.6 ± 2.9 years old, height: 176.0 ± 5.5 cm, body mass: 77.0 ± 1.5 kg, fat percentage: 7.85% ± 0.3%, professional experience: 5.5 ± 1.5 years). Remarkably, our findings revealed striking similarities between the two weight divisions. Furthermore, we discovered a negative correlation between VO2 peak and the number of MMA fights, indicating a potential impact of professional experience on aerobic capacity (r = -0.65, p < 0.01). Additionally, the number of fights exhibited negative correlations with anaerobic energy (r = -0.53, p < 0.05) and total energy cost (r = -0.54, p < 0.05). These results provide valuable insights for designing training programs in the context of MMA. While training both weight divisions together can be beneficial, it is equally crucial to incorporate specific weight-class-focused training to address each division's unique physical demands and requirements., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Gonçalves, Miarka, Maurício, Teixeira, Brito, Ignácio Valenzuela Pérez, Slimani, Znazen, Bragazzi and Reis.)

Aims: To evaluate peppermint essential oil (PEO) inhalation's effect on young soccer athletes' motor performance., Methods: A randomized crossover design was used to test the effect of the PEO. Eleven U-17 soccer players were evaluated into two conditions (PEO and Placebo - PLA). The players were tested in squat jump and countermovement jump and inhaled PEO or PLA and 10 min later performed the physical tests again. A mixed ANOVA was performed to test the hypotheses., Results: Main effects were found for the time in jumping height in the CMJ (p = 0.037). No main and interaction effects were found in the SJ variables., Conclusion: From the results, decrease CMJ performance acutely, both conditions presented decrease in JH, but based in effect size, PLA decrease is higher (more sample size for corroborate this) possibly due to improvements in the eccentric yielding sub-phase, where mentioned phase could be reflecting neural changes (required experimental verification). The PEO could be the interest in trainers for use before of match or in the half-time for minimize the decreased of physical performance by the rest., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

In judo combat, the approach and gripping phases play a crucial role in determining victory, and it is believed that they can be influenced by the current rules. The objective of this study was to compare the technical-tactical actions executed by female judokas in the approach and gripping subphases during international competitions held in the 2016 and 2020 Olympic cycles, which featured different rules. We analyzed 1332 combat videos from the top 20 female judo athletes in the world rankings. These videos were equally distributed across weight divisions in the 2016 and 2020 Olympic cycles (48 kg = 132; 52 kg = 72; 57 kg = 109; 63 kg = 96; 70 kg = 69; 78 kg = 106; >78 kg = 82; total = 666 combats per cycle). The athletes in the 2020 cycle spent more time executing approach actions without contact with the judogi (formless: 2020 = 26.9; 2016 = 21.3 s; p < 0.001) and less time attempting grips (2020 = 24.6; 2016 = 31.2 s; p < 0.001) than the 2016 athletes. Additionally, the 2020 athletes spent less time on one-handed grips (left collar: 2020 = 7.1; 2016 = 7.9 s; p = 0.017; right sleeve: 2020 = 4.6; 2016 = 5.6 s; p = 0.018; left sleeve: 2020 = 4.7; 2016 = 5.2 s; p = 0.031) compared to the 2016 athletes. In both Olympic cycles, athletes devoted the most time to traditional grips (left collar right sleeve: 2016 = 12.3 ± 19.9; 2020 = 12.2 ± 17.5; right collar left sleeve: 2016 = 11.5 ± 20.6; 2020 = 12.3 ± 19.9 s). Differences in the approach subphases between Olympic cycles had varying impacts on different weight divisions (formless = 52 kg, 57 kg, 78 kg; right anteroposterior = 52 kg, 57 kg, 70 kg; grip attempts = 57 kg, 63 kg, 70 kg, 78 kg, >78 kg; p < 0.05), as did changes in grip types (right collar; left collar; left sleeve = 70 kg; right sleeve = >78 kg; right dorsal = 63 kg; left dorsal = 63 kg, 78 kg; right collar left sleeve = 48 kg, 52 kg; right dorsal left sleeve = 78 kg; right dorsal left collar = 48 kg, 70 kg; right dorsal left dorsal = 48 kg, 63 kg; p < 0.05). There were notable technical-tactical shifts in the behavior of female athletes between the Olympic cycles with different rules, and these findings should be taken into account for specialized training in female judo., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests., (© 2023 The Authors. Published by Elsevier Ltd.)

Infrared thermography (IRT) is a technology easy to use for clinical purposes as a pre-diagnostic tool for many health conditions. However, the analysis process of a thermographic image needs to be meticulous to make an appropriate decision. The adipose tissue is considered a potential influence factor in the skin temperature (Tsk) values obtained by IRT. This study aimed to verify the influence of body fat percentage (%BF) on Tsk measured by IRT in male adolescents. A total of 100 adolescents (16.79 ± 0.97 years old and body mass index of 18.41 ± 2.32 kg/m²) was divided into two groups through the results of a dual-energy X-ray absorptiometry analysis: obese ( n = 50, %BF 30.21 ± 3.79) and non-obese ( n = 50, %BF 11.33 ± 3.08). Thermograms were obtained by a FLIR T420 infrared camera and analyzed by ThermoHuman ® software version 2.12, subdividing the body into seven regions of interest (ROI). The results showed that obese adolescents presented lower mean Tsk values than the non-obese for all ROIs ( p < 0.05), with emphasis on the global Tsk (0.91 °C) and anterior (1.28 °C) and posterior trunk (1.18 °C), with "very large" effect size values. A negative correlation was observed in all the ROI ( p < 0.01), mainly in the anterior (r = -0.71, p < 0.001) and posterior trunk (r = -0.65, p < 0.001). Tables of thermal normality were proposed for different ROIs according to the classification of obesity. In conclusion, the %BF affects the registered Tsk values in male Brazilian adolescents assessed by IRT.

Coaches and psychologists can use time-motion analysis to elaborate specific interventions for female BJJ athletes, increasing specific training context and reducing unnecessary psychological and physical demands and injuries. Therefore, the present study aimed to analyze high-level BJJ female athletes in the 2020 Pan-American Games by comparing the weight categories on the time-motion analysis. The time-motion analysis (i.e., approach, gripping, attack, defensive actions, transition, mounting, guard, side control, and submissions) of 422 high-level female BJJ combats was divided and compared by weight category as follows: Rooster ( n  = 8), Light Feather ( n  = 18), Feather ( n  = 122), Light ( n  = 84), Middle ( n  = 74), Medium Heavy ( n  = 44), Heavy ( n  = 36), Super Heavy ( n  = 36), using p  ≤ 0.05. The main results indicated that the Super heavyweight category [3.1 (5.8;119.9) s] had a shorter gripping time than other weight categories, p  ≤ 0.05. In contrast, roosters [7.2 (3.5;64.6) s] had longer gripping, transition [14.0 (4.8;29.6) s], and attack time [76.2 (27.7, 93.2)] than the light feather, middlers, and heavier weight categories, p  ≤ 0.05. These findings should be considered for the psychological interventions and training prescription., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Santos, Soto, de Brito, Brito, Aedo-Muñoz, Slimani, Bragazzi, Znazen and Miarka.)

This study compared the time of female judo combat phases in international competitions between two Olympic cycles (2016; 2020) according to weight divisions (48 kg = 132; 52 kg = 72; 57 kg = 109; 63 kg = 96; 70 kg = 69; 78 kg = 106; >78 kg = 82; total = 666 combats/cycle). The behaviors of 1,332 high-level female judo combats were randomly observed over two Olympic cycles (2016 = 666; 2020 = 666) from the top 20 athletes in the world ranking by weight division. We performed time-motion analysis according to the combat phase and sequential judo actions (approach, gripping, attack, defense, groundwork, pause, and effort: pause ratio) considering the moment when the combat ended (Regular time = RT; Golden score = GS). The weight division groups were compared between Olympic cycles (2016; 2020), and p < 0.05 was defined as significant. The main results showed that 2020 athletes spent less time in the gripping ( p  = 0.005), attack ( p < 0.001), defense ( p < 0.001), groundwork ( p< 0.001) and pause ( p  = 0.002) phases than 2016 athletes. However, compared by the end-of-combat, 2020 female athletes spent less time in all combat phases for RT combats ( p < 0.001), and more time in the approach phase for GS combats ( p < 0.05) than in 2016. The 2016 weight divisions showed a higher diversity in the effort: pause ratio (2.5:1-3.4:1), whereas the 2020 weight divisions had values closer to each other (2.8,1-3:1). Analyzing each weight division separately and by the end-of-combat, the main results showed that ( p < 0.05): 48, 63, 70, and 78 kg reduced the time in almost every phase of RT combat (except for: 63 kg = gripping and attack; 70 kg = approach and groundwork; 78 kg = approach); 48 and 57 kg increased the groundwork time in GS combats whereas 78 kg decreased; 52 kg and 78 kg increased the GS approach time. The temporal behavior of the combats changed between the Olympic cycles with different rules. These data must be considered to understand the characteristics of each group and to prescribe specialized training in female judo., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Barreto, Miarka, dos Santos Silva, Bragazzi, Slimani, Znazen, Soto, Aedo-Muñoz and Brito.)

Background: Due to the absence of evidence in the literature on Paralympic Powerlifting the present study investigated various methods to assess bench press maximum repetition and the way each method influences the measurement of minimum velocity limit (MVT), load at zero velocity (LD0), and force-velocity (FV)., Objective: To evaluate the precision of the multi-point method using proximal loads (40, 50, 60, 70, 80, and 90% of one repetition maximum; 1RM) compared to the four-point method (50, 60, 70, and 80% of 1RM) and the two-point method using distant loads (40 and 80% and 50 and 80% of 1RM) in in the MVT, LD0, and FV, in bench press performed by Paralympic Powerlifters (PP)., Methods: To accomplish this, 15 male elite PP athletes participated in the study (age: 27.7 ± 5.7 years; BM: 74.0 ± 19.5 kg). All participants performed an adapted bench press test (free weight) with 6 loads (40, 50, 60, 70, 80, and 90% 1RM), 4 loads (50, 60, 70, and 80% 1RM), and 2 loads (40-80% and 50-80% 1RM). The 1RM predictions were made by MVT, LD0, and FV., Results: The main results indicated that the multiple (4 and 6) pointsmethod provides good results in the MVT (R 2  = 0.482), the LD0 (R 2  = 0.614), and the FV (R 2  = 0.508). The two-point method (50-80%) showed a higher mean in MVT [1268.2 ± 502.0 N; ICC95% 0.76 (0.31-0.92)], in LD0 [1504.1 ± 597.3 N; 0.63 (0.17-0.86)], and in FV [1479.2 ± 636.0 N; 0.60 (0.10-0.86)]., Conclusion: The multiple-point method (4 and 6 points) and the two-point method (40-80%) using the MVT, LD0, and FV all showed a good ability to predict bench press 1RM in PP., (© 2022. The Author(s).)

This research study verified the technical-tactical actions during the mixed martial arts (MMA) fights to generate serious enough injury to stop the MMA round, determining technical-tactical potential risk factors for injury in official MMA combats, according to Concussion or Resignation per Submission. A total of 990 rounds with concussions and 627 resignations per submission were considered with severe injury (i.e., a fight ended by a doctor or referee). All injuries were diagnosed and managed by attending ringside physicians during the MMA fights and rounds and had a continuous technical-tactical behavior analysis, p ≤ 0.05. The leading cause of concussion was due to head trauma (~90%), with higher dependence on head strikes scored actions. Comparisons between Concussion and Resignation per Submission combats demonstrated differences between distance head strikes actions [13(6,25) vs. 9(4,18) frequencies], clinch head strikes actions [1(0;4) vs . 1(0;3) frequencies], ground head strikes actions [1(0;8) vs. 2(0;10) frequencies] and takedowns actions [0(0;1) vs . 1(0;2) frequencies]. This information may provide significant evidence regarding the doctor stoppage in concussion combats and when it could be called by officials supervising MMA., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Miarka, Soto, Aedo-Muñoz, Maurício, Müller, Bragazzi and Brito.)

Our study evaluated the effect of training with neurofeedback (NFB) in improving athletes' reaction time and decision-making. A computerized search in PubMed, PsycINFO, Scielo, Web of Science, EMBASE, Scopus, BVS, and Cochrane databases was performed to identify studies published from 2011 to June 2021. The protocol was registered in PROSPERO. The quality of studies that was peer-reviewed and included was assessed using the Review Manager tool, Cochrane Risk of Bias, and design and reporting quality according to the CRED-nf checklist. Standard mean differences and 95% confidence intervals (CIs) were calculated and combined using a random-effects model. A total of 07 randomized controlled trials (RCTs) (173 athletes) met the inclusion criteria. Significant effects of NFB in the experimental group in relation to reaction time were found, indicating an improvement in sports performance [standardized mean difference (SMD) = -1.08; 95% CI = (-1.90, -0.25), p = 0.0009] and cognitive performance vs. decision-making with moderate effect [SMD = 1.12; 95% CI = (-0.40, 1.85), p = 0.0001]. However, the control group had a very small effect on cognitive performance [SMD = 0.19; 95% CI = (-0.20, 0.59), p = 0.086]. NFB could improve athletes' reaction time and decision-making, effectively increasing their performance in the sports field. Future studies should focus on standardized protocols for NFB training., Systematic Review Registration: http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021258387., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Brito, Fernandes, Esteves, Müller, Alexandria, Pérez, Slimani, Brito, Bragazzi and Miarka.)

Purpose of Review: To verify the effects of sodium bicarbonate (NaHCO 3 ) supplementation on biochemical and physical measurements of combat sports athletes., Recent Findings: A systematic review of articles indexed in three databases (PubMed, CAPES journal, and Google Scholar) was carried out until October 2020, using descriptors related to NaHCO 3 supplementation in combat sports. First, 38 articles were identified. Next, eight articles were selected through the inclusion and exclusion criteria. The methodological quality of the articles was assessed using the Physiotherapy Evidence Database (PEDro) scale (8 and 9 points). Blood lactate, rating of perceived exertion, Special Judo Fitness Test, Dummy throw, and mean and peak powers for Wingate were evaluated. Random effects meta-analysis was used, the effect size was adjusted by corrected Hedges' g, and the heterogeneity is explored by I 2 . The results were obtained through weighted average and 95% CI, and the significance limit was set as p < 0.05. NaHCO 3 supplementation had a significant effect on increasing blood lactate (p = 0.006) of the athletes studied. However, the performance measures (rating of perceived exertion, power, and specific performance) did not show a significant difference (p ˂ 0.05). In conclusion, NaHCO 3 supplementation causes a significant increase in blood lactate, indicating an ergogenic effect on buffer, which can delay the onset of fatigue and contribute to the performance of combat sports athletes. New experimental studies need to be published that assess the effect of acute and chronic NaHCO 3 supplementation in specific combat sports tests and in women., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Given the relevance of the effects that weight loss can generate on the physical performance in athletes, this study performed a systematic review with meta-analysis of the published literature on rapid weight loss (RWL) and examined its impact on the physical performance in Official Olympic combat sports athletes. The "Preferred Reporting Items for Systematic Reviews and Meta-Analysis" (PRISMA) guidelines were followed to ensure an ethical and complete reporting of the findings. PubMed, SPORT Discus, and EBSCO were the electronic databases explored for article retrieval and selection. The following string was applied: "RWL" OR "weight loss" OR "weight reduction" AND "judo" OR "wrestling" or "taekwondo" or "boxing" AND "performance." Based on the quality analysis, conducted according to the "Tool for the assessment of study quality and reporting in exercise training studies" (TESTEX), ten articles achieved a score >6 points. The meta-analysis showed a significant difference in pre- vs. post-weight loss ( p = 0.003) and no effects in pre- vs. post-power and strength performance analysis ( p > 0.05 for both results). Based on our systematic review and meta-analysis of the literature, RWL up to ≤5% of the body mass in less than 7 days does not influence performance outcomes in Official Olympic combat athletes with weight classes, considering the strength and power measures., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Mauricio, Merino, Merlo, Vargas, Chávez, Pérez, Aedo-Muñoz, Slimani, Brito, Bragazzi and Miarka.)

Introduction: Introduction: central obesity is associated with an autonomic dysfunction characterized by an increase in sympathetic activity and a reduction in vagal tone, leading to a decrease in heart rate variability. Objective: we aimed to analyze the relationship between the time and frequency domains of heart rate variability with central obesity, and its hemodynamic variables in normal-weight, overweight and obese adults. Methods: a total of 65 adults were evaluated (25.4 ± 3.2 years old) and distributed in 3 groups: normal weight group (NW group), overweight group (OW group) and obese group (OB group). Heart rate variability parameters at rest and both anthropometric and hemodynamic variables were recorded. Results: the results showed a positive correlation between waist circunference and LF/HF ratio in the OW (p = 0.0008; r = 0.6607; r2 = 0.4365) and OB (p = 0.0001; r = 0.8286; r2 = 0.6866) groups. The waist-to-height ratio showed significant differences with HF in the NW, OW, and OB groups. The variables related to the parasympathetic system (SDNN, RMSSD, pNN50, HF) in the OB and OW groups showed a decrease in values when compared to the NW group. Likewise, the variable related to the sympathetic system (LF) in the OB and OW groups increased its values when compared with the NW group. The LF/HF ratio increased from the NW group to the OW and OB groups (1.6 ± 0.7; 2.5 ± 1.8 and 3.3 ± 0.7). Conclusion: overweight and obese adults present a modulation of sympathetic activity predominance at rest. This increased activity is represented by the time and frequency domains of heart rate variability, having an important correlation with waist circumference and waist-to-height ratio.

This study aimed to synthesize literature data on male judo combat time in international competitions between 2010 and 2019. The search was carried out from May 8th to June 11th, 2021, in electronic databases using the following keywords: ("technical-tactical" OR "time motion" OR "combat time") AND ("judo" OR "combat sports" OR "martial arts"). After the selection process, 8 articles were included in the systematic review and 7 in the meta-analysis. These studies analyzed 2,562 international male judo combats over the years 2010-2019. We observed that the average male judo combat time changed (2010 = 202.8; 2011-2012 = 304.8; 2016 = 237.4; 2018-2019 = 189.8 s) after each rule change (2010, 2013, 2017, and 2018). There was a significant difference between combats that ended up to the regular time and those that needed overtime (Golden Score: 2013 = 3% vs. 2018-2019 = 21%; p = 0.03). There were differences between 60 kg ( p ≤ 0.019) and + 100 kg ( p ≤ 0.04) categories and the others in 2011-2012. However, no significant difference was found between the combat time by weight division after the 2017 rule changes, although there are still differences in relation to the end of the combats ( p < 0.001). There were significant changes in the male judo combat time with each rule change (2010, 2013, 2017, and 2018), and the data from the included studies point to a trend of homogeneity in the combat time spent between the weight divisions over the years, and an increase in the occurrence of Golden Score. More studies need to be carried out to identify the new temporal behaviors of athletes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Barreto, Santos, Fernandes Da Costa, Valenzuela, Martins, Slimani, Bragazzi, Miarka and Brito.)

This study verifies associated factors with trait and state anxiety in professional soccer teams during the COVID-19 pandemic. The sample was composed of 315 athletes, coaches, and physical trainers of professional soccer teams during the COVID-19 pandemic. From this amount, 214 were classified with trait anxiety, and 315 were classified with state anxiety using the State-Trait Anxiety Inventory (STAI). This study is an epidemiological and cross-sectional study. We applied an observational method, and we performed a remote measurement. The measurement was made via online questionnaires in male and female individuals working on soccer teams (soccer professionals or athletes) who could be affected by anxiety during social isolation in the COVID-19 pandemic. Each questionnaire was composed of sociodemographic questions, self-perceived performance, and STAI. The main results indicated a significant difference between female vs. male soccer professionals in state anxiety (54.97 ± 9.43 vs. 57.65 ± 9.48 index) and trait anxiety (54.21 ± 5.74 vs. 55.76 ± 6.41 index) with higher results in men. Sociodemographic variables impacted significant differences between female and male athletes and professionals of soccer clubs, and anxiety during the pandemic COVID-19 period impacted self-perceived performance analysis. The present results highlight the importance of cognitive behavior therapy for professional soccer teams., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Esteves, Brito, Müller, Brito, Valenzuela Pérez, Slimani, Bragazzi and Miarka.)

This study aimed to determine the impact of a soccer game on the creatine kinase (Ck) response and recovery and the specific Global Positioning System (GPS)-accelerometry-derived performance analysis during matches and comparing playing positions. A sample composed of 118 observations of 24 professional soccer teams of the Brazil League Serie A was recruited and classified according to playing positions, i.e., Left/Right Defenders ( D = 30, age: 25.2 ± 5.8 years, height: 187 ± 5.5 cm, weight: 80 ± 5.8 kg), Offensive Midfielders (OM = 44, age: 25.1 ± 0.2 years, height: 177 ± 0.3 cm, weight: 73 ± 1.2 kg), Forwards ( F = 9, age: 25.1 ± 0.2 years, height: 176.9 ± 4.3 cm, weight: 74.5 ± 2.1 kg), Left/Right Wingers ( M = 23, age: 24.5 ± 0.5 years, height: 175 ± 1.1 cm, weight: 74 ± 4.4 kg), and Strikers ( S = 12, age: 28 ± 0.2 years, height: 184 ± 1.0 cm, weight: 80 ± 1.4 kg). Blood Ck concentration was measured pre-, immediately post-, and 24 h postgame, and the GPS-accelerometry parameters were assessed during games. Findings demonstrated that Ck concentrations were higher at all postgame moments when compared with pregame, with incomplete recovery markers being identified up to 24 h after the game (range: 402-835 U/L). Moreover, Midfielders (108.6 ± 5.6 m/min) and Forwards (109.1 ± 8.3 m/min) had a higher relative distance vs. other positions (100.9 ± 10.1 m/min). Strikers [8.2 (8.1, 9.05) load/min] and Defenders [8.45 (8, 8.8) load/min] demonstrated lower load/min than Wingers [9.5 (9.2, 9.8) load/min], Midfielders [10.6 (9.9, 11.67) load/min], and Forwards [11 (10.65, 11, 15) load/min]. These results could be used to adopt specific training programs and recovery strategies after match according to the playing positions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Freire, Brito, Esteves, Tannure, Slimani, Znazen, Bragazzi, Brito, Soto, Gonçalves and Miarka.)

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The present study aimed to verify the quarantine's effects during a serious viral outbreak on the cardiovascular and performance associated with the Yo-Yo test in a sample of professional soccer players. 20 high-level soccer players ( n = 20; age: 26 ± 4 years-old; weight: 76.85 ± 6.7 kg; height: 179 ± 6 cm) participated in this study. The intermittent Yo-Yo test was performed pre- and post- COVID-19 quarantine in a random order. During each test, the soccer players' running performance outcomes were monitored using a portable 5-Hz GPS with a 100 Hz accelerometer and a paired t -test was conducted at a p -value of ≤ 0.05. The main results demonstrated significant differences between pre- versus post-COVID-19 quarantine in the following variables: relative distance (161.7 ± 5.9 > 141.1 ± 33.8 m/min), maximal speed (18.7 ± 0.9 > 18.2 ± 0.6 km/h), acceleration (60 ± 20 frequency > 52 ± 16 frequency), deceleration (34 ± 13 frequency > 27 ± 6 frequency), sprints > 19 km/h [0.8 (0.2;3)% >0.5 (0;0.5)%], and in high intensity running distance [16.48 (2.68;41.64)m > 0.827 (0.164;3.0)m]. We concluded that COVID-19-related restrictions and quarantine COVID-19 demonstrated adverse effects on professional soccer players' Yo-Yo tests performance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Albuquerque Freire, Tannure, Sampaio, Slimani, Znazen, Bragazzi, Aedo-Muñoz, Sobarzo Soto, Brito and Miarka.)

This study aimed to perform motor action and biomechanical analysis of techniques in female judo athletes separated by weight categories of 638 female bouts (103 extra lightweight <48 kg, 140 half lightweight 48>52 kg, 65 lightweight 52>57 kg, 73 half middleweight 57>63 kg, 77 middleweight 63>70 kg, 80 half heavyweight 70>78 kg and 60 heavyweight >78 kg). All bouts were analyzed following the phases of approach, gripping, defensive action, attack, also biomechanical analysis of techniques and groundwork was performed (p ≤ .05). Results indicated that lightweight athletes presented lower attempts to grip, right collar grip and left collar grip frequencies than other categories. Extra lightweight judokas presented lower right back grip and left back and sleeve grip frequencies as well as lower occurrence of techniques with arm and leg lever scored than half lightweight athletes, while half lightweight athletes demonstrated higher frequency of techniques with waist lever variable scored than lightweight ones. These findings should be considered for training prescription., (© 2020 Dany Alexis Sobarzo Soto, Esteban Aedo-Muñoz, Ciro José Brito, Bianca Miarka, published by Sciendo.)

Brito, CJ, Moreira, DG, Ferreira, JJ, Díaz-de-Durana, AL, Miarka, B, Bouzas Marins, JC, and Sillero-Quintana, M. Immune response related with skin thermal pattern in judokas: A new application for infrared thermography? J Strength Cond Res 34(10): 2886-2894, 2020-This study investigated the association between body skin temperature (BST) and immune response after judo training, and compared the immune responses considering 2 post-training skin thermal pattern ("spots"-SPT and "localized"-LOC). For this, we evaluated 32 (25-male) black-belt judokas from the Spanish Junior National Team (18.0 ± 3.5 years, 72.4 ± 18.4 kg, and 17.1 ± 7.5% body fat). White blood cell and BST measurements were performed at pre-training, immediately, 1, and 24-hour post-training. Body skin temperature (° C) was estimated by skin temperature from 4 regions of interest (chest, upper arm, thigh, and calf). The main results indicated that 13 judokas were classified as SPT and 19 as LOC. In comparison with LOC, SPT had a significantly lower BST post-training (SPT = 33.0 ± 0.4 vs. LOC = 33.6 ± 0.8° C; p = 0.016), lower blood concentration of leukocytes (SPT = 7.9 ± 1.9 vs. LOC = 8.9 ± 1.9 cells × 10 per mm; p ≤ 0.001), and neutrophils (SPT = 5.5 ± 1.7 vs. LOC = 6.1 ± 2.2 cells × 10 per mm; p ≤ 0.001). In conclusion, the BST and immune response after judo training seem to be not associated. However, when the skin thermal pattern is considered, the SPT skin thermal pattern presented a lower post-training BST, blood leukocytes, and neutrophils in comparison with the LOC group. These results show a possible relationship between skin thermal pattern and immune responses for the first time; however, further studies are needed to confirm the evidence presented here.

Purposes : To determine actions during bouts that generate serious enough injury to stop the bout; verifying the injury incidence, types, and prevalence of doctor stoppages (doc-stoppage); and identify potential risk factors by analyzing technical-tactical profiles for injury in sanctioned mixed martial arts bouts taking place over a 12-y period. Methods : This research analyzed 440 paired mixed martial arts matches separated by doc-stoppage (n = 220) and no doc-stoppage (n = 220) from 2002 to 2014. Technical knockouts for doc-stoppage were diagnosed and managed by attending ringside doctors, and the time-motion variables were categorized into total combat time separated by low- or high-intensity activities per round, stand-up, or groundwork actions, P  ≤ .05. Results : The main cause of injuries in doc-stoppage situations was due to facial injuries (>90%), with 87.1% occurring after striking actions during the second round. Lacerations were the leading type of injury, which occurred with 80% frequency. The results showed differences between doc-stoppage and no doc-stoppage for standing combat with low-intensity actions (130.6 [8.5] s vs 83.3 [6.9] s for first round; 115.7 [10.5] s vs 100.1 [9.6] s for second round, and 121.5 [19.5] s vs 106.3 [11.7] s for third round) and total strike attempts (34.5, 23.0-51.8 vs 25.0, 12.0-40.8); in standing combat, head strike attempts (21, 10-33 vs 11, 4-21) and body strikes (2.5, 1.0-5.8 vs 1.0-2), and in groundwork combat, head strikes landed (0.0-3.0 vs 0.0-5.0). Conclusions : This research showed higher values of strike attempts with 2 main orientations, namely the head (on the ground and in stand-up actions) and body (in stand-up actions), and may provide important information regarding the technical knockout and when it can be called by officials supervising mixed martial arts bouts.

This study verified the performance probabilities by mixed martial arts rounds by the same athletes, doing paired comparisons of time-motion and actions before and after 10 y. The sample was composed of 845 Ultimate Fighting Championship rounds of 45 athletes separated into before (M1, age range 34-44 y) and after (M2, age range 44-54 y). Motor-control (takedowns, submissions, chokes, locks, strike actions to the head, and body and leg strikes attempted and landed) and time-motion (high and low intensities and standing and ground times) analyses were done. The main results showed significant differences (P ≤ .05) in total strikes landed (M1 22 [13; 34] > M2 18 [10; 31.7]), total strikes attempted (M1 41 [24.5; 62] > M2 35 [21; 48]), single head strikes attempted (M1 19 [9; 34.5] > M2 16.5 [9; 28]), single body strikes landed (M1 1 [0; 4] > M2 1 [0; 2]), single body strikes attempted (M1 2 [0; 5] > M2 1 [0; 3]), takedowns attempted (M1 1 [0; 2] > M2 1 [0; 2]), standing combat time (M1 2:10.28 [1:38.95] > M2 1:55.56 [1:32.17]), and low-intensity time (M1 2:11.45 [1:38.95] > M2 1:56.26 [1:31.89]). Variables that increased the probability to be associated with over the years were body strikes landed, head strikes landed, total strikes landed, and single strikes attempted, whereas body strikes attempted, head strikes attempted, total strikes attempted, and submission attempted had a negative association with mixed martial arts years of experience. Therefore, M2 athletes should be focused on standing combat time combined with strikes-landed actions, targeting the head-it has the highest potential performance probability and avoid unsuccessful body-strike attempts and submissions-which has the lowest potential performance probability over 10 years.

Nitric oxide (NOx) availability in biological systems is associated with either favorable or unfavorable outcomes. In this sense, several studies bring about evidence that unbalanced NOx production may be underlying to the pathophysiology of vascular disorders. Our study investigated the possible association of clinical, biochemical and inflammatory variables with total circulating levels of NOx in elderly patients devoid of major inflammatory conditions. Clinical (demographics, lifestyle, anthropometry, pressoric traits) and biochemical characteristics (lipemic, glycemic and hormonal profiles) were assessed from 168 geriatrics outpatients eligible for primary care for age-related disorders. Furthermore, circulating levels of 10 inflammatory mediators and of NOx were measured. Correlation tests analyzed categorical or continuous traits according to serum NOx and found no association between NOx and any of the clinical or laboratory data but a negative correlation between plasma NOx concentrations and levels of the immune mediator IL17a (r = -0.236; P = 0.004). Evidence for a correlation between circulating NOx and IL17 is already present in the literature, mostly from studies conducted under inflammatory conditions. Our hypothesis is that such negative correlation can be attributed to an endogenous homeostatic system that IL17 production by the constitutively produced NOx from the vascular endothelium., Competing Interests: None.

Type 2 diabetes mellitus (T2DM) consists of a set of metabolic and endocrine disorders which evolve into deficiency in insulin action and hyperglycemia. Physical exercise is considered the main intervention to prevent and control T2DM. Literature has suggested that circulating microRNAs (miRs) help to understand responses to physical activity among diabetic patients. Thus, the aim of this study was to analyze the acute effect of two interventions (strength and cardiovascular) on the total, whole blood circulating concentrations of miR-126, miR-146a and miR-155 in older adults with and without T2DM. A total of 23 male and female older adults (68.2±5.3 years) participated in the trial, 13 of whom presented with controlled T2DM and 10 were nondiabetics. They underwent both interventions separately, performed with intensity from 60% to 70% of reserve heart rate. Glucose and miRs levels were quantified and compared across groups with baseline titers as covariables. Diabetic patients showed more reduction in serum blood glucose than nondiabetics, with a great magnitude of reduction after the strength training intervention, which was paralleled by a positive change of the whole blood circulating levels of miR-146a, but not of the other miRs. Our report supports evidence that miR-146a levels in peripheral blood leukocytes are negatively associated with a state of insulin resistance, which is suggested as a novel marker to trace response to antidiabetic interventions., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Background: Because of the need to measure anthropometric, biochemical and hemodynamic variables for the diagnosis of metabolic syndrome, we realize how difficult it is to analyze large populations, especially children, due to the poor accessibility and the invasive character. There is an urgent need to develop easy-to-use, accurate and low-cost diagnostic tools in order to predict metabolic syndrome at early ages., Objective: To verify the prevalence of metabolic syndrome in children and to test predictive anthropometric indicators., Methods: Cross-sectional study conducted among 109 children aged 7 to 11 years. The age-adjusted National Cholesterol Education Program definition was used for the diagnosis of metabolic syndrome. The following parameters were tested as possible predictors: body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), conicity index (C index), and body fat percentage., Results: The prevalence of metabolic syndrome was 13.3% and 36% for boys and girls, respectively. The main anthropometric indicators were: BMI = 0.81 (0.69 - 0.94), WC = 0.79 (0.64 - 0.94), body fat = 0.79 (0.66 - 0.92) and WHR = 0.37 (0.21 - 0.54)., Conclusion: WC higher than 78 cm, body fat higher than 41%, and BMI higher than 24.5 kg/m² were considered predictors of metabolic syndrome. The C index and WHR were not considered predictors.

Objective: The increase in inflammatory activity associated with aging is a characteristic of chronic disease processes that accounts for most of the mortality in the elderly. Resistance training (RT) has been shown to promote metabolic and functional benefits in this population. The objective of this study was to investigate the association between long-term RT and circulating levels of the proinflammatory mediators IL-6, TNF-α and IFN-γ in elderly women., Methods: This cross-sectional study included 54 older outpatients divided into a group that underwent RT (n = 28) for an average of 8.6 ± 0.3 months and a sedentary group (n = 26). Measurements were taken only at the end of the intervention, and cytokine values were log-transformed. Dietary intake was controlled as a confounding factor., Results: The RT group presented reduced levels of log₁₀IFN-γ (approx. 45%; p = 0.003), log₁₀IL-6 (approx. 30%; p = 0.002) and log₁₀TNF-α (approx. 22%; p = 0.036). Total caloric intake and systolic arterial blood pressure were significantly lower in the RT group (p = 0.001 and p = 0.022, respectively). Pearson's product moment correlation test revealed a negative association between the fat-free mass (FFM) index and log-transformed IL-6 levels (p = 0.03; n = 54) and a trend towards significance for the correlation between the FFM index and log₁₀IFN-γ (p = 0.05; n = 54)., Conclusion: Long-term, moderate-intensity RT in elderly women is associated with lower circulating levels of cytokines that are potentially implicated in disorders associated with physical inactivity and aging., (2011 S. Karger AG, Basel.)