Effect of High-Intensity Interval Exercise versus Continuous Low-Intensity Aerobic Exercise with Blood Flow Restriction on Psychophysiological Responses: A Randomized Crossover Study.

This study compared the effect of continuous low-intensity aerobic exercise with blood flow restriction (LI-AE-BFR) versus high-intensity interval exercise (HIIE), matching total external mechanical work between conditions, on perceptual (exertion, pain, affective and pleasure) and physiological responses (heart rate [HR], blood lactate [BL] and muscle fatigue). Ten healthy untrained men (25.6 ± 3.78 years old; 75.02 ± 12.02 kg; 172.2 ± 6.76 cm; 24.95 ± 3.16 kg/m²) completed three visits to the laboratory. In visit 1, anthropometry, blood pressure and peak running velocity on the treadmill were measured. In visits 2 and 3, participants were randomly assigned to HIIE or LI-AE-BFR, both in treadmill. HIIE consisted of 10 one-minute stimuli at 80% of peak running velocity interspersed with one-minute of passive recovery. LI-AE-BFR consisted of 20-minutes of continuous walking at 40% of peak running velocity with bilateral cuffs inflated to 50% of arterial occlusion pressure. BL and maximum isometric voluntary contraction (MIVC - fatigue measure) were measured pre- and immediately post-exercise. HR, rating of perceived exertion (RPE), and rating of perceived pain (RPP) were recorded after each stimulus in HIIE and every two minutes in LI-AE-BFR. Affective response to the session, pleasure, and future intention to exercise (FIE) were assessed 10 minutes after the intervention ended. Increases in BL concentrations were greater in HIIE (p = 0.028; r = 0.51). No effects time or condition were reported for MIVC. HR was higher in HIIE at all analyzed time points (p < 0.001; d = 3.1 to 5.2). RPE did not differ between conditions (p > 0.05), while average session RPP was higher in LI-AE-BFR (p = 0.036; r = 0.46). Affective positive response (p = 0.019; d = 0.9) and FIE (p = 0.013; d = 0.97) were significantly higher in HIIE. Therefore, HIIE elicited higher physiological stress, positive affective response, and intention to engage in future exercise bouts compared to LI-AE-BFR.

Evaluation of the Training Session in Elite Paralympic Powerlifting Athletes Based on Biomechanical and Thermal Indicators.

BACKGROUND: Paralympic powerlifting (PP) is performed on a bench press, aiming to lift as much weight as possible in a single repetition. PURPOSE: To evaluate thermal asymmetry and dynamic force parameters with 45 and 80% 1 Repetition Maximum (1 RM) in PP athletes. METHODS: Twelve elite PP male athletes were evaluated before and after a training session regarding skin temperature (thermography) and dynamic force indicators (Average Propulsive Velocity-MPV, Maximum Velocity-VMax, and Power). The training consisted of five series of five repetitions (5 × 5) with 80% 1 RM. The force indicators and dynamics before and after (45% 1 RM) were evaluated in series "1" and "5" with 80% 1 RM. RESULTS: The temperature did not present asymmetry, and there were differences between the moment before and after. In MPV, Vmax, and Power, with 45% 1 RM, there were differences both in asymmetry and in moments (p < 0.005). With 80% 1 RM, asymmetry was observed, but no differences between moments (p < 0.005). CONCLUSION: No thermal asymmetry was observed. There were reductions in MVP and VMax at 45 and 80% 1 RM but without significant differences between time points (before and after). However, there was asymmetry in the moments before and after within a safety standard, where Paralympic powerlifting was safe in terms of asymmetries.

Relative age effects on speed trials in Brazilian athletics.

BACKGROUND: Relative age effect (RAE) is a concept related to the possible advantage that older athletes would have over younger ones within the same category. Although many studies have approached this subject in individual sports, there are few clippings by events within the sport. More detailed analyses are necessary for a better understanding of how RAE behaves in sports, especially in athletics, the subject of this study. The objective of this study was to analyze the RAE on speed in track and field events as a whole, separating the flat races from the hurdles races. METHODS: The Brazilian Ranking of Brazilian Athletics Confederation was used for data analysis, and the sample was composed of the 50 best-placed marks in the ranking of speed events in athletics in the categories Under(U)-16 and U-18 (female and male). Statistical analysis was calculated by chi-square, and the effect size was checked by Cramer's V. Likelihood-ratio test (L-Ratio) assessed the probability of the RAE occurring in the total sample and by age groups. RESULTS: In the total sample the results pointed to the emergence of RAE in males in both categories (U-16: p < 0.001; V: 0.13; L-Ratio: 3.64, U-18: p < 0.001; V: 0.13; L-Ratio: 3.80), whereas in females no such effect was found in any category (U-16: p = 0.6; V: 0.09; L-Ratio: 0.09, U-18: p = 0.6; V: 0.07; L-Ratio: 0.12). When the results were separated by type of event, there was only a RAE in the shallow event in the U-18 female category (p = 0.3; V: 0.11; L-Ratio: 8.72). CONCLUSION: The results allow us to conclude that there is a RAE in the speed trials of Brazilian athletics in the U16 and U18 categories for men, while this effect appears only in the shallow trials of the U18 category for women, indicating that the RAE has incidence when there is more participation and competition in the sport.

Acute Effect of Resistance Training With Blood Flow Restriction on Perceptual Responses: A Systematic Review and Meta-Analysis.

CONTEXT: Several studies have compared perceptual responses between resistance exercise with blood flow restriction and traditional resistance exercise (non-BFR). However, the results were contradictory. OBJECTIVES: To analyze the effect of RE+BFR versus non-BFR resistance exercise [low-load resistance exercise (LL-RE) or high-load resistance exercise (HL-RE)] on perceptual responses. DATA SOURCES: CINAHL, Cochrane Library, PubMed®, Scopus, SPORTDiscus, and Web of Science were searched through August 28, 2021, and again on August 25, 2022. STUDY SELECTION: Studies comparing the effect of RE+BFR versus non-BFR resistance exercise on rate of perceived exertion (RPE) and muscle pain/discomfort were considered. Meta-analyses were conducted using the random effects model. STUDY DESIGN: Systematic review and meta-analysis. LEVEL OF EVIDENCE: Level 2. DATA EXTRACTION: All data were reviewed and extracted independently by 2 reviewers. Disagreements were resolved by a third reviewer. RESULTS: Thirty studies were included in this review. In a fixed repetition scheme, the RPE [standardized mean difference (SMD) = 1.04; P < 0.01] and discomfort (SMD = 1.10; P < 0.01) were higher in RE+BFR than in non-BFR LL-RE, but similar in sets to voluntary failure. There were no significant differences in RPE in the comparisons between RE+BFR and non-BFR HL-RE; after sensitivity analyses, it was found that the RPE was higher in non-BFR HL-RE in a fixed repetition scheme. In sets to voluntary failure, discomfort was higher in RE+BFR versus non-BFR HL-RE (SMD = 0.95; P < 0. 01); however, in a fixed scheme, the results were similar. CONCLUSION: In sets to voluntary failure, RPE is similar between RE+BFR and non-BFR exercise. In fixed repetition schemes, RE+BFR seems to promote higher RPE than non-BFR LL-RE and less than HL-RE. In sets to failure, discomfort appears to be similar between LL-RE with and without BFR; however, RE+BFR appears to promote greater discomfort than HL-RE. In fixed repetition schemes, the discomfort appears to be no different between RE+BFR and HL-RE, but is lower in non-BFR LL-RE.

Relative age effect in elite Brazilian athletes in different combat sports: an observational study.

Background: The relative age effect (RAE) suggests that, due to maturity, young athletes born in the first quartiles of the year may have advantages over those born in the last quartiles of the year. Thus, it is important to evaluate the RAE in different sports and to consider the particularities of the subdivisions of the sports categories. Objective: To analyze the RAE in the top 20 of the Brazilian rankings in different combat sports. Methods: Observational study that analyzed the national databases for the year 2019 (from categories U-11 to U-18) made publicly available by the Brazilian confederations of karate, taekwondo and fencing. We obtained data on date of birth, age category and body weight of all modalities, type of fencing competition weapon (Epee, Foie and Saber) and type of karate modality (kumite and kata) from the top 20 places in each ranking. The final sample consisted of 1,486 athletes (Age: 14.2 ± 2.3. Male-53.2%. Female-46.8%). To identify the RAE, we performed a contingency analysis and compared the results between the sexes within the same sport. Results: There was RAE in the U-11, U-12, U-15 and U-17 fencing categories (p < 0.05), being higher in the female categories (p < 0.05). The RAE was higher for males in the Epee test, and similar between the sexes for the Saber and Foie tests. In karate, RAE occurred in categories U-14 and U-16 (p < 0.05), being higher in males (p < 0.05). The RAE was similar between the sexes in the kumite modality (p < 0.05). There was no RAE for the kata modality in karate (p > 0.05) and for the Taekwondo categories (p > 0.05). Conclusion: The results showed the existence of a relative age effect in elite athletes ranked (top 20 places in each ranking) only for the sport of fencing and karate kumite.

Short-Term Effects of Repeated-Sprint Training on Vertical Jump Ability and Aerobic Fitness in Collegiate Volleyball Players During Pre-Season.

The aim of this study was to assess the effect of repeated-sprint training (RST) on vertical jump ability and aerobic power in college volleyball players. Nineteen male volleyball players, aged between 18-24 years, were randomized into the RST group (RST; n = 10) and control group (CG; n = 9). The RST included 2-3 sets of 6×30m all-out sprints, twice per week, in addition to the regular training routine. The control group performed only the regular volleyball training sessions (i.e. mainly of technical-tactical drills). All players performed a maximal graded treadmill test, vertical countermovement jump (CMJ), and repeated-vertical jump ability (RVJA) test before and after 6-weeks of the training program. The following variables were determined from the RVJA: peak (RVJApeak), average (RVJAmean), and rate of decrement (RVJADec). A two-way ANOVA with repeated measures showed an interaction effect on CMJ (F (1,17) = 6.92; p = 0.018; η 2 = 0.289), RVJApeak (F (1,17) = 4.92; p = 0.040; η 2 = 0.225), maximal oxygen uptake (F (1,17) = 9.29; p = 0.007; η 2 = 0.353) and maximal speed attained in the treadmill test (F (1,17) = 8.66; p = 0.009; η 2 = 0.337), with significant improvements only on the RST group. In conclusion, RST, twice per week, improved RVJA and aerobic power in comparison to regular skill-based volleyball training.

Force-velocity relationship in Paralympic powerlifting: two or multiple-point methods to determine a maximum repetition.

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 (R2 = 0.482), the LD0 (R2 = 0.614), and the FV (R2 = 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.

Evaluation of Ibuprofen Use on the Immune System Indicators and Force in Disabled Paralympic Powerlifters of Different Sport Levels.

Background: Paralympic powerlifting (PP) training is typically intense and causes fatigue and alterations in the immune system. Objective: To analyze whether IBU would affect performance and the immune system after training in PP. Methodology: 10 athletes at the national level (NL) and 10 at the regional level (RL) participated in the study, where force and blood indicators were evaluated after training. The study took place over three weeks: (1) familiarization and (2 and 3) comparison between recovery methods, with ibuprofen or placebo (IBU vs. PLA), 800 mg. In the evaluation of the force, the peak torque (PT), fatigue index (FI), and blood immune system biomarkers were analyzed. The training consisted of five sets of five repetitions with 80% of one maximum repetition (5 × 5, 80% 1RM) on the bench press. Results: The PT at the national level using IBU was higher than with PLA (p = 0.007, η2p = 0.347), and the FI in the NL was lower with IBU than with PLA (p = 0.002, η2p = 0.635), and when comparing the use of IBU, the NL showed less fatigue than the regional level (p = 0.004, η2p = 0.414). Leukocytes, with the use of IBU in the NL group, were greater than in the RL (p = 0.001, η2p = 0.329). Neutrophils, in the NL with IBU, were greater than in the RL with IBU and PLA (p = 0.025, η2p = 0.444). Lymphocytes, in NL with IBU were lower than in RL with IBU and PLA (p = 0.001, η2p = 0.491). Monocytes, in the NL with IBU and PLA, were lower than in the RL with IBU (p = 0.049, η2p = 0.344). For hemoglobin, hematocrit, and erythrocyte, the NL with IBU and PLA were higher than the RL with IBU and PLA (p < 0.05). Ammonia, with the use of IBU in the NL, obtained values higher than in the RL (p = 0.007), and with the use of PLA, the NL was higher than the RL (p = 0.038, η2p = 0.570). Conclusion: The training level tends to influence the immune system and, combined with the use of the IBU, it tends to improve recovery and the immune system.

Reliability of biological maturation analyses performed by equations predicting skeletal age and peak height velocity with hand and wrist X-ray results.

BACKGROUND: Hand-wrist radiography is the gold standard for the assessment of skeletal age (SA) and the assignment of biological maturation (BM) status. However, its practical use in the field is questioned, prompting the development of anthropometric equations to estimate BM. However, there is no consensus on the reliability of these equations in relation to hand-wrist X-rays. OBJECTIVE: To test the reliability of the BM estimated from predictive equations with the results of hand-wrist X-rays. METHODS: One-hundred forty-four young athletes (38%-males, 62%-females; 12.3 ± 1.4 years) were recruited. SA was assessed by analyzing X-rays of the hand-wrist using the Greulich-Pyle protocol. SA was predicted using the anthropometric equations of Cabral and Macêdo. By subtracting chronological age from SA, a measure of BM or biological age (BA) was computed. In addition, a BA of years from peak height velocity (PHV) was predicted using the anthropometric equations of Mirwald and Moore. RESULTS: Relative to X-ray, Cabral's equations showed high reliability in estimating BM in both sexes (p < .0001) while Macêdo's equations showed substantial reliability or males (p < .0001) only. Mirwald and Moore's equations showed weak reliability (p < .05 and p = .043, respectively). CONCLUSION: The prediction of SA using anthropometric equations was found to be reliable in categorizing individuals as late, synchronized, and/or early maturers in both sexes. However, the predictive equations of years from PHV only reliably categorized late and synchronized maturation stages in males and the synchronized maturers in females.

Are sEMG, Velocity and Power Influenced by Athletes' Fixation in Paralympic Powerlifting?

The bench press is performed in parapowerlifting with the back, shoulders, buttocks, legs and heels extended over the bench, and the use of straps to secure the athlete to the bench is optional. Thus, the study evaluated muscle activation, surface electromyography (sEMG), maximum velocity (MaxV) and mean propulsive velocity (MPV), and power in paralympic powerlifting athletes under conditions tied or untied to the bench. Fifteen experienced Paralympic powerlifting male athletes (22.27 ± 10.30 years, 78.5 ± 21.6 kg) took part in the research. The sEMG measurement was performed in the sternal portion of the pectoralis major (PMES), anterior deltoid (AD), long head of the triceps brachii (TRI) and clavicular portion of the pectoralis major (PMCL). The MaxV, MPV and power were evaluated using an encoder. Loads of 40%, 60%, 80% and 100% 1RM were analyzed under untied and tied conditions. No differences were found in muscle activation between the tied and untied conditions; however, sEMG showed differences in the untied condition between AD and TRI (F (3112) = 4.484; p = 0.005) in the 100% 1RM load, between PMCL and AD (F (3112) = 3.743; p = 0.013) in 60% 1RM load and in the tied condition, between the PMES and the AD (F (3112) = 4.067; p = 0.009). There were differences in MaxV (F (3112) = 213.3; p < 0.001), and MPV (F (3112) = 248.2; p < 0.001), between all loads in the tied and untied condition. In power, the load of 100% 1RM differed from all other relative loads (F (3112) = 36.54; p < 0.001) in both conditions. The tied condition seems to favor muscle activation, sEMG, and velocity over the untied condition.

Body adiposity index to analyze the percentage of fat in young men aged between 7 and 17 years.

BACKGROUND: The body adiposity index (BAI), uses anthropometry to estimate percent body fat (%F). However, previous studies have shown that the BAI has limited accuracy for children and adolescents. OBJECTIVE: We propose to develop and validate an adjusted BAI for use in male children and adolescents from 7 to 17 years of age. METHODS: The sample consisted of 141 physically active male children and adolescents (age: 12.5 ± 2.14). The %F was determined by X-ray dual energy absorptometry equipment (DXA) as the standard method and by BAI, using an equation that uses height and hip circumference. Arithmetic modeling was used to adjust the structure of the BAI mathematical model. RESULTS: The BAI arithmetic adjustment was successful, resulting in the mathematical model named in the present study of adjusted body adiposity index (BAIADJ ). BAI and BAIADJ correlated with DXA (r ≤ .70, p < .001). Regression analyzes indicate that, BAI (CI 95% ß: [1.35; 1.90], p < .0001) and BAIADJ (CI 95% ß: [1.40; 1.90], p < .0001) have the potential to estimate %F. BAI pointed out a difference in relation to DXA (p = .04). While there was no difference between BAIADJ and DXA (p = .1). There was a proportion bias of 13.2% for BAI (p < .05), but not for BAIADJ (p > .05). CONCLUSION: The adjusted model of the body adiposity index proves to be an effective tool for the analysis of the fat percentage in young males. In addition, it demonstrated significant degrees of agreement and validity in relation to DXA.

Analysis of Grip Amplitude on Velocity in Paralympic Powerlifting.

(1) Background: Paralympic Powerlifting (PP) is a Paralympic modality that is predominantly about developing maximal force, as there are athletes who lift three times their body weight. Our objective was to evaluate the averages of the velocity for 30% and 50% of 1 Maximum Repetition (1 RM) on different amplitudes of the footprint in PP athletes; (2) Methods: The intervention happened over two weeks, with the first being devoted to the familiarization and testing of 1 RM, while in the second week, through the use of a linear Encoder, tests of velocity average (VA), velocity average propulsive (VAP), and velocity peak (VP) were carried out with loads of 30% and 50% of a maximum repetition 1 RM for 1× of the biacromial distance (BAD) 1.3 × BAD, 1.5 × BAD; (3) Results: There was a significant difference in the average velocity of 1 × BAD (1.16 ± 0.14 m/s, 1.07-1.26 IC; η2p 0.20) when compared to 1.3 × BAD (1.00 ± 0.17 m/s, 0.90-1.09 IC; η2p 0.20) over 30% of 1 RM. For the other velocity variables for 30% and 50% of 1 RM with different grip amplitudes, there were no significant differences; (4) Conclusions: In PP, the 1 × BAD footprint contributes significantly to VA at 30% of 1 RM when compared to the 1.3 × BAD and 1.5 × BAD footprints. For loading at 50% of 1 RM the VA, VAP and VP decreased when compared to 30% of 1 RM, to the extent that the VAP and VP generated with the 1.3 × BAD and 1.5 × BAD footprints were higher than those with 1 × BAD, other than for VA 50% of 1 RM, where the 1 × BAD footprint was superior to the others.

The Management between Comorbidities and Pain Level with Physical Activity in Individuals with Hip Osteoarthritis with Surgical Indication: A Cross-Sectional Study.

Background and Objectives: The degenerative pathology of the hip joint appears in young age groups, related to fem-oroacetabular impingement, and in advanced age, due to other inflammatory causes, with greater potential for severity in the presence of comorbidities. Objectives: To evaluate the participation of the main causes of osteoarthritis in relation to physical activities, s Body Mass Index (BMI) and television time (TV). Materials and Methods: 54 patients with surgical indication treated at an orthopedic referral university hospital were stratified into groups (Impact: I, Osteonecrosis/rheumatic: II, Infectious/traumatic: III), and the influence of comorbidities on physical activity performance, relative to BMI and TV time. Results: It was observed that the impact group was the most frequent (51.8%), with 79.6% under the age of 60 years. This group followed the general mean (p < 0.05), using the variables of comorbidity and the level of physical activity. Pain intensity, TV time, BMI showed no correlation with physical activity. Conclusion: Morphostructural changes (group I) represented the most frequent etiological group, and severe pain was common in almost the entire sample. Unlike BMI, comorbidity showed a significant relationship with the level of physical activity.

Relationship of Biological Maturation with Muscle Power in Young Female Athletes.

There is still no consensus on how biological maturation (BM) affects the muscle power of upper and lower limbs in young people. The objective was to verify associations between BM and muscle power, as well as to compare the muscle power of upper (ULP) and lower limbs (LLP) among young athletes in different stages of BM. The sample consisted of 79 female athletes (10.9 ± 1.11 years old). Regarding BM, the sample was divided into three groups: delayed BM, synchronized BM, and accelerated BM. BM was identified by subtracting chronological age from bone age (BA). BA was measured by a mathematical model based on anthropometry. The muscular power of the upper limbs was analyzed by the medicine ball launch test, and that of the lower limbs was analyzed by the countermovement jump on a force platform. BM and BA correlated with ULP (BA: r =0.74; BM: r =0.65) and LLP (BA: r = 0.50; BM: r =0.41). In the comparisons of the tests of ULP and LLP, the groups with synchronized and accelerated BM were superior to the group with delayed BM. The advance of BM is associated with the ULP and LLP, as well as the advance of the BM affects muscle power in young female athletes. This occurs due to the increase in body mass resulting from the advancement of BM, which may favor the predominance of lean body mass, assisting in the production of muscle strength.

Influence of Healthy Habits Counseling on Biochemical and Metabolic Parameters in Children and Adolescents with HIV: Longitudinal Study.

We analyze the influence of dietary counseling and physical activity on biochemical and metabolic parameters in children and adolescents with HIV. A longitudinal experimental study, including three analyses: At the beginning, 4th month, and 8th month. A sample of 18 subjects with HIV of both sexes, mean age 10.4 ± 4.50 years. Usual food intake (24 h recall and food intake marker), level of habitual physical activity, biochemical parameters, resting metabolic rate, as well as body composition (dual-energy X-ray absorptiometry), biological maturation, and anamnesis with clinical data and socioeconomic were evaluated. There was an effect of time on the reduction of blood glucose and triglycerides and the resting metabolic rate. There was a significant increase in fruit consumption throughout the study. The consumption of soft drinks decreased when comparing analysis periods 1 and 2, however, it increased again in analysis period 3. There was no significant effect of time on the set of variables related to a food recall. Counseling healthy habits and regular clinical follow-up were relevant for improving biochemical parameters (glucose, triglyceride, HDL cholesterol), maintaining the resting metabolic rate, increasing fruit consumption, and decreasing the consumption of soft drinks, in part of the time, of children and adolescents with HIV. Finally, we emphasize that counseling positively influenced healthy habits, and these, in turn, improved health-related parameters.

Are Strength Indicators and Skin Temperature Affected by the Type of Warm-Up in Paralympic Powerlifting Athletes?

(1) Background: the present study aimed to evaluate the effect of different types of warm-ups on the strength and skin temperature of Paralympic powerlifting athletes. (2) Methods: the participants were 15 male Paralympic powerlifting athletes. The effects of three different types of warm-up (without warm-up (WW), traditional warm-up (TW), or stretching warm-up (SW)) were analyzed on static and dynamic strength tests as well as in the skin temperature, which was monitored by thermal imaging. (3) Results: no differences in the dynamic and static indicators of the force were shown in relation to the different types of warm-ups. No significant differences were found in relation to peak torque (p = 0.055, F = 4.560, η2p = 0.246 medium effect), and one-repetition maximum (p = 0.139, F = 3.191, η2p = 0.186, medium effect) between the different types of warm-ups. In the thermographic analysis, there was a significant difference only in the pectoral muscle clavicular portion between the TW (33.04 ± 0.71 °C) and the WW (32.51 ± 0.74 °C) (p = 0.038). The TW method also presented slightly higher values than the SW and WW in the pectoral muscles sternal portion and the deltoid anterior portion, but with p-value > 0.05. (4) Conclusions: the types of warm-ups studied do not seem to interfere with the performance of Paralympic Powerlifting athletes. However, the thermal images showed that traditional warm-up best meets the objectives expected for this preparation phase.

Comparison of Muscle Strength, Aerobic Capacity and Body Composition between Healthy Adolescents and Those Living with HIV: A Systematic Review and Meta-Analysis.

Background: The adverse effects of antiretroviral therapy associated with complications generated by human immunodeficiency virus (HIV) promote impairments in physical fitness in adolescents. Objective: To analyze the aerobic capacity, muscle strength, and body composition of adolescents living with HIV compared with a healthy population of the same age. Methods: Searches were performed in the MEDLINE, Embase, Web of Science, Scopus and SportDiscus databases until September 2019 and updated in April 2020. Eligibility Criteria: adolescents of both sexes in the age group from 10 to 19 years; living with HIV; cross-sectional, case-control, cohort studies; comparing with a healthy population. Mean differences and 95% Confidence intervals (CIs) were calculated using RevMan (software for systematic reviews). Results: Five articles were included, involving 197 adolescents living with HIV (16 to 18 years) and 185 without infection (13 to 18 years), with the sample in each study ranging from 15 to 65 adolescents. Aerobic capacity and muscle strength were reduced in adolescents with HIV, and body mass index was also significantly lower in this group. Conclusion: Adolescents living with HIV have impaired cardiorespiratory fitness, muscle strength, and body composition when compared to their uninfected peers. However, this systematic review provides limited evidence on the differences between the physical fitness outcomes of adolescents living with HIV compared to healthy adolescents.

Effects of Resistance Training on Oxidative Stress Markers and Muscle Damage in Spinal Cord Injured Rats.

BACKGROUND: Spinal cord injury (SCI) is a condition that affects the central nervous system, is characterized by motor and sensory impairments, and impacts individuals' lives. The objective of this study was to evaluate the effects of resistance training on oxidative stress and muscle damage in spinal cord injured rats. METHODOLOGY: Forty Wistar rats were selected and divided equally into five groups: Healthy Control (CON), Sham (SHAM) SCI Untrained group (SCI-U), SCI Trained group (SCI- T), SCI Active Trained group (SCI- AT). Animals in the trained groups were submitted to an incomplete SCI at T9. Thereafter, they performed a protocol of resistance training for four weeks. RESULTS: Significant differences in muscle damage markers and oxidative stress in the trained groups, mainly in SCI- AT, were found. On the other hand, SCI- U group presented higher levels of oxidative stress and biomarkers of LDH and AST. CONCLUSION: The results highlight that resistance training promoted a decrease in oxidative stress and a significative response in muscle damage markers.

Evaluation of the body adiposity index against dual-energy X-ray absorptiometry for assessing body composition in children and adolescents.

BACKGROUND: It is important to clarify the association of lean and fat mass between children and adolescents considering the rising prevalence of overweight and obesity in this age group. The aim of this study was to verify the association between the body adiposity index (BAI) and dual-energy X-ray absorptiometry (DXA) methods for analyzing body composition, as well as analyzing the validity of BAI to verify the percentage of fat in children and adolescents. METHODS: The sample was composed of 106 children and adolescents, 44 females (age: 11.5 ± 1.8 years) and 62 evils (13.6 ± 2.6 years). The body fat (%F) was measured using DXA and the doubly indirect BAI body fat estimation technique. RESULTS: The BAI and DXA estimates of %F were strongly correlated (boys: r = .71, P < .0001; girls: r = .72, P < .0001). The linear regression analyses showed that BAI is significant to estimate the %F in total sample (P < .0001). For boys, the %F analyzes performed by BAI and DXA did not show any differences when compared (P = .2). In addition, BAI pointed out a significant proportion bias for both sexes (P < .0001), which suggests its inefficiency in the analysis of %F. CONCLUSIONS: BAI and DXA correlate; however, there is low reliability and a high proportion bias for the analysis of %F by BAI.

Evaluation of Muscle Damage, Body Temperature, Peak Torque, and Fatigue Index in Three Different Methods of Strength Gain.

The aim of this study was to evaluate and compare three different strength training protocols for the lower limbs by using biochemical indicators of muscle damage, thermographic analysis, and neuromuscular performance. In total, 10 men (age: 22.50 ± 2.84 years; weight, 75.45 ± 6.86 kg) completed the study. All the athletes were subjected to three methods of resistance training (RT): traditional, tension, and occlusion training. Serum concentrations of creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase were used as indicators of muscle damage. To measure muscle strength, the peak force, and fatigue index were determined using a Kratos load cell. Images were captured using an infrared camera (FLIR T640sc). The vascular occlusion method demonstrated a 33% reduction in posttraining peak torque (p < 0.001; η2p: 2.74), which was recovered within 24 h (p < 0.001; η2p: 1.08). The thermographic analysis revealed a reduction in skin temperature in both thighs after the tension (-9.37%) and vascular occlusion (-6.01%) methods. In conclusion, the occlusion training seems to provide additional benefits as compared to the other two methods of strength training.