Discriminating factors of the kinanthropometric profile of young athletes from different sports

Background: Body morphology, due to its simple applicability, is used to help coaches make decisions during the process of identifying and selecting talent in sports. Objective: to analyze the discriminative kinanthropometric patterns of young Brazilian athletes in different sports. Methods: We evaluated 83 young males (age: 13.1 ± 2.4), 60 of whom were athletes (16-soccer, 11-tennis, 20-swimming, and 13-rowing) and 23 non-athletes (Control group). We evaluated the kinanthropometric profile by dual-energy x-ray emission absorptiometry and by anthropometry. Subsequently, through algorithms programmed in “R” language, a discriminant model was created based on the circumference variables: biceps, hips, waist, and leg; the bone diameters of the humerus and femur, and the components of body composition: total lean mass, total fat mass, bone mineral density, bone mineral content, triceps skinfold, and body adiposity index. Results: Discriminant model was able to discriminate soccer athletes in 93.8% (F:32.098; p=0.000), tennis athletes in 81.8% (F:24.060; p=0.0004), rowing athletes in 80% (F:28.031; p=0.0001), swimming at 100% (F:41.899; p<0.000) and the control group at 91.3% (F:30.132; p<0.0001). In addition, the high bone mineral density was important for the discrimination of soccer athletes (p<0.001), the low body adiposity index for the discrimination of swimming athletes (p<0.001), and the high levels of lean mass for the discrimination of rowers (p<0.001). Conclusion: We conclude that morphological patterns can be used safely, helping to discriminate young athletes from different sports; thus, one more tool to be used in the processes of detection and guidance of young people with talent in the sport

Effects of Ibuprofen Use on Lymphocyte Count and Oxidative Stress in Elite Paralympic Powerlifting.

Background: Paralympic Powerlifting (PP) training tends to promote fatigue and oxidative stress. Objective: To analyze the effects of ibuprofen use on performance and oxidative stress in post-training PP athletes. Methodology: Ten national level PP athletes (age: 27.13 ± 5.57) were analyzed for oxidative stress in post-training. The study was carried out in three weeks, (1) familiarization and (2 and 3) evaluated the recovery with the use of a placebo (PLA) and ibuprofen (IBU), 800 mg. The Peak Torque (PT), Torque Development Rate (TDR), Fatigue Index (FI), reactive substances to thiobarbituric acid (TBARS) and sulfhydryl groups (SH) were evaluated. The training consisted of five sets of five repetitions (80–90%) 1-Repetition Maximum (1-RM) in the bench press. Results: The IBU showed a higher PT (24 and 48 h, p = 0.04, ɳ2 p = 0.39), a lower FI (24 h, p = 0.01, ɳ2p = 0.74) and an increased lymphocyte count (p < 0.001; ɳ2p = 4.36). There was no change in oxidative stress. Conclusions: The use of IBU provided improvements in strength and did not protect against oxidative stresspost-print915 K

Relationship of Biological Maturation with Muscle Power in Young Female Athletes

International Journal of Exercise Science 14(6): 696-706, 2021. 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

Relationship between the vertical countermovement jump and the simulated performance of the initial 15 meters of crawl swimming performed by adolescent athletes

Background: The start in swimming occurs via a jump that propels the swimmer into the pool. The relationship of the power generated by the start jump to first 15-m performance in swimming events is not yet known. Objective: Verify the correlation of the countermovement vertical jump (CMJ) with the simulated start performance of the crawl swimming. Materials and Methods: The present research was observational pilot study. The sample consisted of 12 Brazilian swimmers aged between 12 and 16 years (male). The CMJ was analyzed by a specific Platform for Jump Testing. Afterward, the athletes were directed to an Olympic swimming pool and positioned themselves in the starting block. Then, at the sound signal (whistle), they swam the first 15 meters of the pool in crawl style at the highest possible speed to simulate the start of the competition of swimming. Results: Thus, the study showed a negative correlation of the CMJ with the simulated start of 15 meters in the crawl style (r =-0.816; p=0.001). The analyses indicated that the CMJ contributes 66% (F (1.10) = 19.92; p=0.001) for the performance of 15 meters during the simulated start of the crawl stroke. It was shown that for every 1 cm increase in CMJ height, there was an improvement of 0.0885 milliseconds in swimming performance. Conclusion: CMJ is associated with the variation of the sprint time during the simulated start of a swimming test in the crawl swimming style

Evaluation of Training with Elastic Bands on Strength and Fatigue Indicators in Paralympic Powerlifting

Background: Variable resistance training has recently become a component of strength and conditioning programs. Objective: This randomized counterbalanced cross-over study aimed to investigate the use of elastic bands (EB) and the traditional method (TRAD) and force indicators in a training session. Methods: 12 Paralympic athletes (age: 28.60 ± 7.60 years) participated in this three-week study. In the first week, the participants were familiarized with EB and TRAD and were tested for maximal repetition (1-RM). The research occurred in weeks 2 and 3, which included the pre-post training, during which the following measures were extracted: maximum isometric force (MIF), the peak torque (PT), rate of force development (RFD), fatigue index (FI), and time to MIF (Time). The athletes performed two tests, EB and TRAD, separated by a one-week interval. Results: Significant differences were found between the pre- and post-test for 1RM (p = 0.018, η2p = 0.412), MIF (p = 0.011, η2p = 0.415), PT (p = 0.012, η2p = 0.413), and RFD (p = 0.0002, η2p = 0.761). With the use of EB, there was a difference in RFD between TRAD before and EB after (p = 0.016, η2p = 0.761). There were significant differences in the before and after for FI between TRAD and EB (p < 0.001) and for Time (p < 0.001), indicating that training with the use of elastic bands promotes overload, characterized by increased fatigue and decreased strength. Conclusions: Training with EB did not decrease 1RM, PT, MIF or RFD, however, there was an increase in fatigue and time to reach MIF when compared to the method with fixed resistance

Can the Neuromuscular Performance of Young Athletes Be Influenced by Hormone Levels and Different Stages of Puberty?

Background: Endocrine mechanisms can be a determining factor in the neuromuscular performance of young athletes. Objective: The objective of the present study was to relate maturational and hormonal markers to neuromuscular performance, as well as to verify whether young athletes with different testosterone levels show differences in muscle strength. Methods: The sample consisted of 37 young male Brazilian athletes (11.3 &plusmn; 0.94 years) who were members of a sports initiation project. Hormonal markers were analyzed biochemically by blood samples, and maturation markers by mathematical models based on anthropometry. Body composition was verified by tetrapolar bioimpedance. The performance of upper and lower limb strength and body speed were analyzed. Results: Hormonal and maturational markers were related to neuromuscular performance (p &lt; 0.05). Young people with higher testosterone levels showed higher muscle strength (p &lt; 0.05). Artificial neural networks showed that testosterone predicted the performance of upper limbs by 49%, and maturation by 60%. Maturation foreshadowed the performance of lower limbs by 30.3%. Conclusion: Biological maturation and hormonal levels can be related to neuromuscular performance, and young people with higher testosterone levels show superior muscle strength in relation to the others

Evaluation of Training with Elastic Bands on Strength and Fatigue Indicators in Paralympic Powerlifting

Background: Variable resistance training has recently become a component of strength and conditioning programs. Objective: This randomized counterbalanced cross-over study aimed to investigate the use of elastic bands (EB) and the traditional method (TRAD) and force indicators in a training session. Methods: 12 Paralympic athletes (age: 28.60 ± 7.60 years) participated in this three-week study. In the first week, the participants were familiarized with EB and TRAD and were tested for maximal repetition (1-RM). The research occurred in weeks 2 and 3, which included the pre-post training, during which the following measures were extracted: maximum isometric force (MIF), the peak torque (PT), rate of force development (RFD), fatigue index (FI), and time to MIF (Time). The athletes performed two tests, EB and TRAD, separated by a one-week interval. Results: Significant differences were found between the pre- and post-test for 1RM (p = 0.018, η2p = 0.412), MIF (p = 0.011, η2p = 0.415), PT (p = 0.012, η2p = 0.413), and RFD (p = 0.0002, η2p = 0.761). With the use of EB, there was a difference in RFD between TRAD before and EB after (p = 0.016, η2p = 0.761). There were significant differences in the before and after for FI between TRAD and EB (p &lt; 0.001) and for Time (p &lt; 0.001), indicating that training with the use of elastic bands promotes overload, characterized by increased fatigue and decreased strength. Conclusions: Training with EB did not decrease 1RM, PT, MIF or RFD, however, there was an increase in fatigue and time to reach MIF when compared to the method with fixed resistance

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