Impact of social isolation on the level of physical activity in young Brazilian athletes caused by COVID-19.

BACKGROUND: Social detachment to prevent the spread of the COVID-19 pandemics in the year 2020 can significantly contribute to the physical inactivity of citizens worldwide. The study aimed to analyze the level of physical activity by identifying the training methods used during the social isolation resulting from the COVID-19 pandemic. METHODS: Sixty-eight Brazilian athletes (both sexes, 14.7±1.68 years) answered and adapted the International Physical Activity Questionnaire (I-PAQ) through an online platform. Participants were asked to report their level of physical activity before and during the period of social distance. RESULTS: According to our results, 67.7% of the interviewed athletes said they were able to adapt their sports training to the isolation environment under the guidance of a distance physical education professional. Only 4.38% of the sample was not training under such supervision and, therefore, inactive. Among the activities performed in the isolation environment, calisthenics was the primary practice (effect size: ƒ2=0.50, P<0.0001) and the sport practiced at home was the secondary practice (effect size: ƒ2=0.27, P=0.004). During the pandemic, the training hours of athletes reduced significantly from ~3h to ~1h per day (effect size: 1.74, P<0.0001), as well as the perceived intensity decreased from "high" to "moderate" (effect size: 1.38, P<0.0001). The weekly training frequency decreased from ~6 to 7 days to ~3 to 5 days (effect size: 0.40, P=0.03). CONCLUSIONS: Despite the social distance and the reduced pace of training, the young Brazilian athletes analyzed managed to remain physically active during the COVID-19 pandemic.

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.

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 stress.

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.

The influence of biological maturation and neuromuscular performance on peak bone mineral density in children.

BACKGROUND: The growth and development cycle of the adult is characterized by substantial changes in physical size and maturity, and is controlled by the simultaneous influence of genetic components and the environment. Changes in the development of bones, muscles and adipose tissue are among the most important aspects of adolescent physical development. The aim of this research was to examine the correlation between bone mineral density (BMD) and neuromuscular performance in children at different stages of maturation. METHODS: The study included 31 participants of both sexes (11.7±1.89 years). Body composition was assessed through bone densitometry using an energy duo X-ray source. The neuromuscular performance of the upper limbs was analyzed by the medicine ball hand grip and throwing tests. The lower limbs by the vertical counter-motion jump test, and skeletal maturation was analyzed by bone age. Maturation was used as an effect control between the association of BMD and neuromuscular performance. RESULTS: The results demonstrated significant associations between the performance of upper (P<0.0001) and lower (P=0.01) limbs and BMD. On inter-group comparison for only the accelerated maturational stage, male participants had greater BMD than female participants (P=0.001; effect size 3.13). Regarding the maturational stages, male participants in the accelerated maturational stage demonstrated higher BMD than those in the normal and delayed maturational stages (P=0.04; effect size 3.10), whereas female participants did not demonstrate significant differences in BMD accumulation. CONCLUSIONS: BMD has a strong correlation with the neuromuscular performance of upper and lower limbs of children of both sexes.

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 ± 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 < 0.05). Young people with higher testosterone levels showed higher muscle strength (p < 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.