Effects of Ischemic Preconditioning on Sport-Specific Performance in Highly Trained Taekwondo Athletes.

Ischemic preconditioning (IPC), which involves episodes of blood flow restriction followed by reperfusion, has uncertain effects on athletes. Additionally, employing sports-specific tests that are highly familiar to athletes can enhance methodological rigor in determining IPC's effects on taekwondo performance. This study aimed to investigate IPC's influence on taekwondo athletes' performance through two studies. To induce occlusion in both studies, the cuff was inflated to an individualized occlusion pressure established for each athlete's lower limb, with four cycles of occlusion lasting five minutes each, alternated with five-minute reperfusion intervals. Both traditional frequentist statistics and Bayesian analysis were employed. In the first study, eleven high-level athletes were subjected to either IPC or a placebo (SHAM) procedure on both legs, followed by performing countermovement jumps (CMJs) and a specific taekwondo endurance test. However, no significant differences were observed in taekwondo endurance performance or CMJ between the IPC and SHAM conditions. The second study involved fourteen elite athletes who underwent the same IPC or SHAM conditions, performing CMJ and three bouts of the Multiple Frequency Speed of Kick test (FSKTmult) in three blocks, each separated by approximately thirty minutes. Again, the results indicated no significant differences in FSKTmult measures or CMJ performance between the two conditions. In conclusion, IPC did not significantly affect neuromuscular (in both studies), endurance (in the first study), or anaerobic (in the second study) performance in these taekwondo athletes.

Evaluating the Stroop Test With Older Adults: Construct Validity, Short Term Test-Retest Reliability, and Sensitivity to Mental Fatigue.

We conducted two studies to evaluate the construct validity, short term test-retest reliability, and sensitivity to mental fatigue of the Stroop task when used with older adults. In Study 1, 40 participants visited our lab on two separate days. On the first visit, they took five screening scales, and we measured their height and body mass. On the second visit, they completed the Stroop task twice with a 30-minute interval between assessments. In Study 2, 15 different participants took a 30-minute Flanker/Reverse Flanker task during the interval between the two administrations of the Stroop tasks and they gave subjective ratings of their mental fatigue on the Visual Analogue Scale (VAS) prior to taking either of the Stroop tasks. In Study 1, participants showed a ceiling effect on the Stroop accuracy measure, there was strong concurrent validity for the Stroop with significant score differences between the Stroop's congruent and incongruent conditions (p < .001), and there was excellent response time reliability (ICC = 0.926) on day two when participants took the Stroop twice within a 30-minute inter-test interval. However, there were significant test-retest performance differences with respect to cognitive inhibition (p < .001). In Study 2, mental fatigue from the Flanker/Reverse Flanker test resulted in a significantly worse second Stroop performance (p = .045). We concluded that the Stroop task demonstrated strong concurrent validity and response time reliability among older adults, but it showed sensitivity to mental fatigue, and repeated administrations within the short 30-minute test-retest interval revealed that the most important Stroop measure (cognitive inhibition) was unreliable. We discuss the implications of these findings.

Monitoring Training Loads in Judo Athletes: Different Time Courses of Physiological, Neuromuscular, and Perceptual Responses.

This study aims to elucidate the internal load, performance, physiological, and perceptual recovery responses during four weeks of traditional judo training. Ten cadet and junior judo athletes were evaluated daily for four weeks, in which their perception of recovery, heart rate variability, handgrip strength, and countermovement jump performance were assessed. A one-way repeated-measures ANOVA was performed to analyze the variables across the weeks. A significant time effect in internal load (F = 6.51; p = 0.001) has been observed. Handgrip test performance showed significantly higher values in the 3rd and 4th weeks (p <0.001), while countermovement jump performance was significantly higher in the 4th week (p =0.0007). The heart rate variability's coefficient of variation was lower in both the 3rd and 4th weeks (p =0.02). Regarding perceptual aspects, the Hooper Index showed a significant time effect (p =0.04), but pairwise comparison did not reveal differences between weeks. The present study indicates that neuromuscular, physiological, and perceptual responses to training load alterations present different time courses. This must be considered for the adequate monitoring of training programs.

Acute Effects of Fitlight Training on Cognitive-Motor Processes in Young Basketball Players.

Cognitive-motor training could be used to improve open-skill sport performances, increasing cognitive demands to stimulate executive function (EF) development. Nevertheless, a distributed training proposal for the improvement of EFs is increasingly difficult to combine with seasonal sport commitments. This study aimed to investigate whether a massed basketball training program enriched with Fitlight training can improve EFs and motor performance. Forty-nine players (age = 15.0 ± 1.5 yrs) were assigned to the control and Fitlight-trained (FITL) groups, which performed 3 weeks of massed basketball practice, including 25 min per day of shooting sessions or Fitlight training, respectively. All athletes were tested in cognitive tasks (Flanker/Reverse Flanker; Digit Span) and fitness tests (Agility T-test; Yo-Yo IR1). During the intervention, exercise/session perceived effort (eRPE/sRPE) and enjoyment were collected. RM-ANOVA showed significant EFs scores increased in both groups over time, without differences between the groups. Moreover, an increased sRPE and eRPE appeared in the FITL group (p = 0.0001; p = 0.01), with no group differences in activity enjoyment and fitness tests. Three weeks of massed basketball training improved EFs and motor performance in young players. The additional Fitlight training increased the perceived cognitive effort without decreasing enjoyment, even if it seems unable to induce additional improvements in EFs.

Playing videogames or using social media applications on smartphones causes mental fatigue and impairs decision-making performance in amateur boxers.

This study aimed to analyze the effect of playing videogames and using social media applications on smartphones on decision-making and countermovement jump (CMJ) performance in amateur boxers. Twenty one boxers were enrolled in the study and were randomly assigned to all three experimental conditions [smartphone (30SMA), videogame (30VID), and control (CON)]. CMJ was measured before and 30-min after each experimental condition. The athletes ran simulated combat recorded for decision-making analysis. The boxers watched coaching videos (CON), used social media applications on smartphones (30SMA), and played video games (30VID) for 30 min just before the combat simulation. Both attack and defense decision-making performance were worse in both 30SMA and 30VID conditions compared to the CON condition (p = 0.001). Regarding CMJ, despite no condition effect (p = 0.96) been obtained, a time effect (p = 0.001) was observed; So, it was found a decrease in CMJ performance after all experimental conditions (p = 0.001), with no difference between them. Using social media applications on smartphones and playing video game impairs decision-making performance in amateur boxers, with no harms for CMJ performance.

Effect of Whole-, Upper-, and Lower-Body High-Intensity Rowing Exercise on Skin Temperature Measured by Thermography.

Purpose: Despite the growing works analyzing exercise-induced thermoregulatory adjustments through thermography, the skin temperature (Tsk) response of the same muscle groups underwent to different exercise demands has not been investigated. This study analyzed the behavior of Tsk of the same muscle groups when exercised with different demands in rowing. Methods: Eighteen men underwent three performance tests on a rowing ergometer: whole-body 2,000 m test (RTWB), upper-body (RTUB), and lower-body (RTLB) tests. In each condition, thermograms were recorded before (pre), immediately after test (post), and at 10 (REC10), 20 (REC20), and 30 (REC30) minutes post-exercise recovery. Tsk was measured at the pectoral (control body region), upper back, quadriceps, brachial biceps, and forearm. Results: Pectoral-Tsk reduced comparably in response to all testing conditions (p < .05). Upper back-Tsk decreased post (p < .001) and returned to baseline in the RTUB (REC10, p = 1.0) and RTWB (REC30, p = .128), while remained reduced in the RTLB (p < .001). Quadriceps-Tsk reduced post (p < .05) and returned to baseline in the RTWB and RTLB at REC10 (p = 1.0), remaining reduced in the RTUB during recovery (p < .05). Regarding the upper limbs, Tsk increased more markedly in the RTUB versus RTWB during the recovery period (p < .05); in the RTLB, biceps-Tsk remained below baseline over time (p < .05), whereas the forearm-Tsk was restored at REC10 (p = 1.0). Conclusion: Manipulating the muscle groups involved in rowing alters the Tsk response within equal ROI. Exercise-induced Tsk changes can reflect local hemodynamic and thermoregulatory adjustments.

Do executive function performance, gaze behavior, and pupil size change during incremental acute physical exercise?

Several studies have investigated the interaction between acute physical exercise and cognitive performance. However, few studies have investigated this issue during acute high-intensity exercise. In the present study, we evaluated executive functions (EFs) during incremental exercise in three different intensities [below lactate threshold (LT), at LT, and above LT], measuring EFs performance, gaze behavior, and pupil diameter. Twenty subjects were familiarized with the EFs test and participated in a graded maximal exercise test on a cycle ergometer on the first visit. On the second visit, they performed the EFs task at rest and while exercising at three different intensities using mobile eye-tracking glasses. Our results showed that the psychophysiological measures differed between the conditions. Regarding EFs performance, during exercise above LT, the subjects showed worse accuracy when compared with rest (p < .001) and below LT (p < .001). In addition, the response time (RT) at LT and above LT was shorter than in the rest condition (p < .050). Further, RT was faster (p = .002) in the above LT than in the below LT condition. In addition, the gaze behavior measures indicated that exercise, independently of the intensity, improves the number of fixations with shorter fixation durations compared to the rest condition (p < .050). Additionally, we found no significant differences in average and peak pupil diameter between conditions. In conclusion, exercise at LT improves the EFs performance while exercising above LT worsens EFs performance. However, there were no significant differences in average and peak pupil diameter between conditions.

Are COMT Val158Met (rs4680), DRD2 TaqIA (rs1800497), and BDNF Val66Met (rs6265) polymorphisms associated with executive functions performance at rest and during physical exercise?

Executive functions (EFs) encompass a wide array of cognitive processes, which appear to be influenced by genetic variants of the COMT, DRD2/ANKK1, and BDNF polymorphisms. The present study aimed to investigate whether COMT Val158Met (rs4680), DRD2/ANKK1 (rs1800497), and BDNF Val66Met (rs6265) polymorphisms were associated with EFs assessed at rest and during moderate acute physical exercise. Sixty physically active individuals underwent four laboratory visits. First, they filled out the pre-exercise survey, researchers collected their anthropometric data, and then performed a maximal cardiopulmonary exercise test. In the second and third sessions, participants performed EFs test in a randomized order: while the individual was seated on a cycle ergometer without pedaling (i.e., rest condition); and during physical exercise (pedaling for 30 minutes at moderate intensity before starting the EFs test during exercising). On the fourth day, blood samples were drawn. Our results showed that the response time of the COMT Val homozygotes group was significantly shorter than the COMT Met-carrier group [t(39.78) = 2.13, p = .039,d = 0.56] at rest condition. No significant association was found for the other analyses (DRD2/ANKK1 and BDNF). In conclusion, the present study suggests that COMT Val158Met (rs4680) polymorphisms may be associated with EFs at rest condition. However, further studies are needed to validate this association.

Reliability of physical performance and thermoregulatory parameters in rats subjected to incremental treadmill running.

Thermoregulatory changes may influence the rats' prolonged physical performance and are commonly evaluated during treadmill running. Therefore, we determined the reliability of performance and thermoregulatory parameters in rats subjected to incremental-speed exercises (i.e., we assessed whether the testing protocol provides measurements that are consistent and free from error). Twenty rats were subjected to two sessions of incremental exercises at 24 °C, separated by 48 h, until they were fatigued. The rats' performance and thermoregulatory responses were determined, and values concerning the reliability of these parameters [e.g., intraclass correlation coefficient (ICC) and minimal detectable change (MDC)] were calculated. Our data revealed that the core temperature (TCORE) at fatigue and heat loss threshold were the most reproducible parameters, showing good reliability (ICC between 0.75 and 0.90). Moreover, all performance parameters assessed, the change in TCORE, the rate of TCORE increase, and the TCORE increase-to-distance traveled ratio presented moderate reliability. We then investigated whether changes in performance and thermoregulation induced by a warm environment were greater than the MDC95% values determined in the first experiment. Eight rats were subjected to incremental exercises at two environmental conditions: 24 °C and 31 °C. Individual analyses showed that most rats presented thermoregulatory differences between exercises at 31 °C and 24 °C greater than the calculated MDC95% values; this was not the case for their performance. In conclusion, we provide data on the reliability of rats' performance and thermoregulatory parameters during incremental-speed running. Also, the exercise in a warm environment produced detectable thermoregulatory changes relative to the exercise under temperate conditions.

Multicomponent exercise training is effective in improving health and behavior indicators in Brazilian elderly women: A non-randomized trial.

OBJECTIVE: The aim was to evaluate the effects of a supervised 12-week Multicomponent exercise training on elderly women health and behavior indicators. METHODS: Anthropometric characteristics and body composition, functional capacity, sedentary behavior, physical activity level and biochemical profile were evaluated in the control group (67.2 ± 5.2 years, n = 14) and in the experimental group (67.4 ± 6.1 years, n = 41). The experimental group were composed by 41 elderly women who performed 12 weeks of Multicomponent exercise training involving strength, aerobic, flexibility and balance exercises. The inclusion criteria for the study were women aged 60 years or more and presentation of a medical certificate authorizing the practice of physical exercise. RESULTS: Maintenance of anthropometric characteristics and body composition was observed in both groups (p > 0.05). There was an improvement in aerobic capacity, lower and upper limb strength in the experimental group (p < 0.01), while the control group showed a reduction in aerobic capacity, lower limb strength, agility and dynamic balance (p < 0.01), as shown in Fi.gure 3. There was a reduction in sedentary behavior and an increase in physical activity level in experimental group (p < 0.05), but not in control group. Experimental group showed an improvement in glucose levels and lipid profile (p < 0.01). CONCLUSION: Multicomponent exercise training was efficient to improve health and behavior indicators of the elderly women.

Non-invasive brain stimulation over the orbital prefrontal cortex maintains endurance performance in mentally fatigued swimmers.

BACKGROUND: Using anodal transcranial direct current stimulation (a-tDCS) on frontal brain areas might be a promising strategy to mitigates mental fatigue and maintain endurance performance swimmers. OBJECTIVE: The objective was to analyze the effect of a-tDCS over the orbital prefrontal cortex (oPFC) on endurance performance of mentally fatigued female amateur swimmer. METHODS: Nineteen female amateur swimmers participated in this study. In two experimental visits, the swimmers completed the 3-min all-out tethered swimming after performing a 30-min Stroop test with a-tDCS or placebo (Sham) stimulation over the left-oPFC. The brain stimulation conditions (i.e., a-tDCS and Sham) were performed in a double-blinded and counterbalanced order. RESULTS: It was found lower critical force, mean force, force minimum, fatigue index, and aerobic impulse for Sham than a-tDCS (p < 0.05). There was no main effect of condition for peak force (p >  0.05). CONCLUSION: We concluded that a-tDCS applied over the left-oPFC in female amateur swimmers mentally fatigued maintained endurance performance. From a practical point of view, the use of a-tDCS should be considered to counteract harmful cognitive effects and maintain endurance performance during competitive race events.

Development and reliability of a test for assessing executive functions during exercise.

Previous research suggests that performance on executive functions tests may be different at rest, versus when one is engaged in physical exercise. Therefore, the present study aimed to develop an integrated system that evaluates executive functions during exercise. We conducted two test-retest studies, with ten healthy male volunteers participating in each study. Participants visited the laboratory three (Study 1) or four (Study 2) times. During the first visit in both studies, questionnaires were administered, and a maximal cardiopulmonary exercise test (CPT) was performed. In Study 1, during the second and third visits, participants exercised on a cycle ergometer at a moderate intensity for 30 minutes before starting the Flanker/Reverse Flanker test while they were still cycling. In Study 2, during the second visit, participants performed three sets of the executive functions test while sitting on the bike, with a 5 min interval between each set. On visits 3 and 4, participants performed the same exercise protocol as the one described in Study 1. In summary, our results indicated that the Flanker/Reverse Flanker test that we developed and conducted in exercising individuals has similar elements to previous versions and can be considered a reliable test for executive functions assessment during exercise.

Effects of social media on smartphone use before and during velocity-based resistance exercise on cognitive interference control and physiological measures in trained adults.

The purpose is to analyze the effect of social networks on smartphones before and during velocity-based resistance exercise on the internal training load, heart rate variability (HRV), and cognitive interference control. Twelve trained adults volunteered to participate in this randomized and crossover design research study with three experimental conditions. The participants randomly performed a resistance exercise session, watching TV before (CON) the session or using social networks on a smartphone prior to (30SMA-P) and intra-session (SMA-INT). The participants underwent sets with repetitions [15RM load] up to 20% mean velocity loss. HRV indicators and cognitive interference control were measured before and 30-min after each experimental session. Internal training load was evaluated 30-min after each experimental session, which was calculated by the product between resistance exercise volume and RPE. No condition versus time interaction for HRV indicators (p > 0.05) was observed. It was not revealed a condition versus time interaction for cognitive interference control (p > 0.05). No condition effect for internal training load (p > 0.05) was observed. It was concluded that 30-min of social networks on smartphones before or intra-session resistance exercise had no effects on HRV indicators, cognitive interference control, and internal training load in trained adults.

Association between motor competence and executive functions in children.

Previous studies investigating the relationship between executive functions (EFs) and motor competence (MC) in typically developing children have produced inconsistent findings regarding the association's strength and nature. Thus, the present study aimed to explore the relationship between EFs and MC in typically developing children aged 6-11 years old. Additionally, we aimed to explore the relationship between EFs and MC in younger (6-8 years old) and older (9-11 years old) typically developing children. In total, 152 children of both sexes performed the Flanker/Reverse Flanker test, Tower of London, Raven's Colored Matrices, Körperkoordinations Test Für Kinder, and Test of Gross Motor Development. Using the global score of MC and EFs and controlling for age, our results showed a significant and medium correlation between MC and EFs (r = 0.380, p < .001). Moreover, the correlation in younger children (r = 0.470), as well as in older (r = 0.272) children were significant. The regression analysis also showed that MC predicts EFs performance in all participants, in younger children, and older children, although with less explained variance for older children. In short, our study suggests that it is needed to promote the development of MC and EFs in children, especially the younger ones.

Relationship between Indirect Measures of Aerobic and Muscle Power with Frequency Speed of Kick Test Multiple Performance in Taekwondo Athletes.

This study aimed to determine the relationship between indirect measures of aerobic power and muscular power with Frequency Speed of Kick Test performance using multiple sets (FSKTmult) in high-level taekwondo athletes. We used a known-group method to test differences in FSKTmult performance between two groups designated as lower and higher performance in both aerobic power and muscular power. In total, 42 international or national taekwondo athletes of both sexes performed the FSKTmult, Progressive Specific Taekwondo Test (PSTT), and countermovement jump (CMJ). Our results showed that average of the three CMJ was moderately correlated with FSKTmult performance (r=0.44); whereas PSTT and FSKTmult were highly correlated (r=0.83). Moreover, the groups formed by lower and higher performance of time to exhaustion in PSTT, as well as the average of CMJ were able to discriminate performance in the FSKTmult (p ≤0.05). The present study thus suggests that aerobic and muscle power are important for FSKTmult performance.

Psychiatric disorders in individuals born very preterm / very low-birth weight: An individual participant data (IPD) meta-analysis.

BACKGROUND: Data on psychiatric disorders in survivors born very preterm (VP; <32 weeks) or very low birthweight (VLBW; <1500 g) are sparse. We compared rates of psychiatric diagnoses between VP/VLBW and term-born, normal birthweight (term/NBW) control participants. METHODS: This individual participant data (IPD) meta-analysis pooled data from eligible groups in the Adults born Preterm International Collaboration (APIC). Inclusion criteria included: 1) VP/VLBW group (birth weight <1500 g and/or gestational age <32 weeks), 2) normal birth weight/term-born control group (birth weight >2499 g and/or gestational age ≥37 weeks), and 3) structured measure of psychiatric diagnoses using DSM or ICD criteria. Diagnoses of interest were Attention Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), Anxiety Disorder, Mood Disorder, Disruptive Behaviour Disorder (DBD), Eating Disorder, and Psychotic Disorder. A systematic search for eligible studies was conducted (PROSPERO Registration Number 47555). FINDINGS: Data were obtained from 10 studies (1385 VP/VLBW participants, 1780 controls), using a range of instruments and approaches to assigning diagnoses. Those born VP/VLBW had ten times higher odds of meeting criteria for ASD (odds ratio [OR] 10·6, 95% confidence interval [CI] 2·50, 44·7), five times higher odds of meeting criteria for ADHD (OR 5·42, 95% CI 3·10, 9·46), twice the odds of meeting criteria for Anxiety Disorder (OR 1·91, 95% CI 1·36, 2·69), and 1·5 times the odds of meeting criteria for Mood Disorder (OR 1·51, 95% CI 1·08, 2·12) than controls. This pattern of findings was consistent within age (<18 years vs. ≥18 years) and sex subgroups. INTERPRETATION: Our data suggests that individuals born VP/VLBW might have higher odds of meeting criteria for certain psychiatric disorders through childhood and into adulthood than term/NBW controls. Further research is needed to corroborate our results and identify factors associated with psychiatric disorders in individuals born VP/VLBW. FUNDING: Australia's National Health & Medical Research Council; CAPES (Coordenação de Aperfeiçoamento de Pessoal deNível Superior) - International Cooperation General Program; Canadian Institutes of Health Research Team Grant; National Council for Scientific and Technological Development (CNPq); Academy of Finland; Sigrid Juselius Foundation; Signe and Ane Gyllenberg Foundation; European Union's Horizon 2020 research and innovation programme: Project RECAP-Preterm; European Commission Dynamics of Inequality Across the Life-course: structures and processes (DIAL); Neurologic Foundation of New Zealand; MRC programme grant; Health Research Council of New Zealand; National Institutes of Health, USA; The Research Council of Norway; Joint Research Committee between St. Olavs Hospital and Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU); Liaison Committee between Central Norway Regional Health Authority and NTNU.

Effect of mental fatigue on mean propulsive velocity, countermovement jump, and 100-m and 200-m dash performance in male college sprinters.

The objective of this study was to analyze the effect of mental fatigue on mean propulsive velocity (MPV), countermovement jump (CMJ), 100, and 200-m dash performance in college sprinters. A total of 16 male athletes of sprint events (100 and 200-m dash) participated in this study. Each participant underwent two baseline visits and then running under the three experimental conditions. Assessments (MPV and CMJ) occurred both before and after either smartphone use (SMA) or Stroop task (ST), or watching a documentary TV show about the Olympic Games (CON). Then, the athletes ran the simulated race (i.e. the 100 and 200-m dash). There was no condition (p > 0.05) or time effect (p > 0.05) for MPV, CMJ, 100-m, or 200-m dash performance. In conclusion, the present study results revealed no mental fatigue effect induced by SMA or ST on neuromuscular, 100-m or 200-m dash performance in male college sprinters.

Effects of smartphone use before resistance exercise on inhibitory control, heart rate variability, and countermovement jump.

BACKGROUND: The effect of MF induced by exposure time to social media smartphone apps on inhibitory control, heart rate variability (HRV), and high-intensity physical effort following a resistance exercise session might indicate whether strength and conditioning professionals should suggest avoiding smartphone usage before a resistance exercise session. AIM: The objective of this study was to analyze the effect of mental fatigue on inhibitory control, HRV, and countermovement jump (CMJ) in trained adults after resistance exercise. METHODS: A total of 16 trained males (21.4 ± 3.3 years) volunteered in this study. The participants performed resistance exercises with and without mental fatigue. The Stroop Task, countermovement jump, and heart rate variability were evaluated before and after the resistance exercise. The participants used smartphones in the mental fatigue condition, whereas the participants watched TV in the control condition. RESULTS: No condition × time interaction was found for the Stroop accuracy (p = 0.87), CMJ (p = 0.68), SDNN (p = 0.15), or pNN50 (p = 0.15) in the heart rate variability. An interaction was found for Stroop response time (p = 0.01) with a higher response time for the mental fatigue condition (p = 0.01). CONCLUSIONS: Mental fatigue impaired the inhibitory control performance after a resistance exercise session in trained adults.

Validity of the estimated body fat percentage by bioimpedance and skinfolds in middle-aged and elderly women / Validez del porcentaje de grasa corporal estimado por bioimpedancia y pliegues cutáneos en mujeres de mediana edad y ancianas

Objectives: Verify the validity of electrical bioimpedance (BIA) and the skinfold method in estimating the percentage ofbody fat (% BF) in middle-aged and elderly women, using dual emission X-ray absorptiometry (DXA) as a reference method.Material and methods: The sample consisted of 106 volunteers (middle age, n = 58 [51.3 ± 4.9 years] and elderly, n = 48[67.2 ± 5.8 years]). The volunteers were submitted to anthropometric assessments and the % BF was subsequently calculatedusing the Jackson and Pollock 7 skinfold protocol (7SF). The % BF was also measured using BIA and DXA. Pearson’s correlation,Bland and Altman method, effect size and repeated-measure t-test were used to test the hypotheses.Results: Although there is a moderate positive relationship between the methods evaluated for middle-aged women (DXAvs 7SF, r = 0.67; DXA vs BIA, r = 0.62) and moderate to strong for the elderly (DXA vs 7SF, r = 0.57; DXA vs BIA, r = 0.75) (p ≤ 0.05in all analyzes), the agreement between the methods was weak (limits of agreement > ± 3.5%). Additionally, when assessingthe % BF mean using each method within the groups, it was observed that there was no significant difference between theestimates only between DXA and Pollock 7SF in the elderly group.Conclusion: Therefore, both the 7SF method and the BIA are not valid for estimating body fat in the sample evaluated. It isnecessary to develop equations for specific skinfolds to estimate the % BF of middle-aged and elderly women and reviewthe equations used by the BIA.(AU)

Objetivo: Verificar la validez de la bioimpedancia eléctrica (BIA) y el método del pliegue cutáneo en la estimación delporcentaje de grasa corporal (% GC) en mujeres de mediana edad y ancianas, mediante la doble emisión de rayos X (DXA )como método de referencia.Material y método: La muestra estuvo formada por 106 voluntarias (mediana edad, n = 58 [51,3 ± 4,9 años] y ancianas, n= 48 [67,2 ± 5,8 años]). Las voluntarias fueron sometidas a evaluaciones antropométricas y, posteriormente, se calculó el %GC utilizando el protocolo de pliegues cutáneos Jackson y Pollock 7 (7PC). El% de GC también se midió usando BIA y DXA.La correlación de Pearson, el método de Bland y Altman, el tamaño del efecto y la prueba t de medida repetida se utilizaronpara probar las hipótesis.Resultados: Aunque existe una relación positiva moderada entre los métodos evaluados para mujeres de mediana edad (DXAvs 7PC, r = 0,67; DXA vs BIA, r = 0,62) y moderada a fuerte para las ancianas (DXA vs 7PC, r = 0,57 ; DXA vs BIA, r = 0,75) (p ≤ 0,05en todos los análisis), la concordancia entre los métodos fue débil (límites de acuerdo > ± 3,5%). Además, al evaluar la mediade % GC usando cada método dentro de los grupos, se observó que no hubo diferencia significativa entre las estimacionessolo entre DXA y Pollock 7PC en el grupo de ancianas.Conclusiones: Por tanto, tanto el método 7PC como el BIA no son válidos para estimar la grasa corporal en la muestra eva-luada. Es necesario desarrollar ecuaciones para pliegues cutáneos específicos para estimar el % GC de mujeres de medianaedad y ancianas y revisar las ecuaciones utilizadas por el BIA.(AU)

Correlation between strength and skin temperature asymmetries in the lower limbs of Brazilian elite soccer players before and after a competitive season.

This study aimed to investigate the correlation between strength and skin temperature (Tsk) asymmetries in the lower limbs of elite soccer players before and after a competitive season. The sample (n = 20) was composed of elite male soccer players. Strength asymmetry and Tsk asymmetry was measured through the countermovement jump (CMJ) test and infrared thermography, respectively. Asymmetries were quantified using the symmetry angle (SA) equation. A strong correlation was found between the SA of rate of force development (RFD) and the SA of Tsk before (baseline) (r = 0.7; r2 = 0.43; p = 0.03) and after (r = 0.6; r2 = 0.42; p = 0.04) the competitive season. Moreover, after the competitive season there were significant decreases in Peak force (p < 0.018), Impulse (p < 0.04), RFD (p = 0.0001) and CMJ height (p = 0.05), and significant increases in Tsk (p < 0.03), C-reactive protein (p = 0.03), Creatine kinase (p = 0.0001) and Cortisol (p = 0.04), even after a 3-day rest interval (no training). These results suggest that the CMJ test can be combined with infrared thermography for monitoring strength asymmetry and contribute to the prevention of muscle injuries.