Estudo da tecnologia de acesso Wi-Fie suas aplicações em ambientes indoor e outdoor

Wireless communications is a feature that has become indispensable for many people in the whole world. Through this feature, communication process can become much more efficient, allowing people to access information much more quickly wherever they are. The constant evolution of communication technologies allows the development of new unthinkable applications and services. This new range of possibilities brings greater mobility and efficiency for final users and also helps service providers and carriers to improve the quality of services offered by them. This study presents the principles of wireless communication and the Wi-Fi technology as well as its most modern applications, covering from the basics of computer networks to the procedures of planning a wireless network, concepts of radio frequency, antennas, patterns, regulatory agencies, network equipment, protocols and network monitoring

Kinesio Taping effects on knee extension force among soccer players

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Specific determination of maximal lactate steady state in soccer players

The aim of this study was to establish the validity of the anaerobic threshold (AT) determined on the soccer-specific Hoff circuit (AT(Hoff)) to predict the maximal lactate steady-state exercise intensity (MLSSHoff) with the ball. Sixteen soccer players (age: 16.0 +/- 0.5 years; body mass: 63.7 +/- 9.0 kg; and height: 169.4 +/- 5.3 cm) were submitted to 5 progressive efforts (7.0-11.0 km.h(-1)) with ball dribbling. Thereafter, 11 players were submitted to 3 efforts of 30 minutes at 100, 105, and 110% of AT(Hoff). The AT(Hoff) corresponded to the speed relative to 3.5 mmol.L-1 lactate concentration. The speed relative to 4.0 mmol.L-1 was assumed to be AT(Hoff4.0), and the AT(HoffBI) was determined through bisegmented adjustment. For comparisons, Student's t-test, intraclass correlation coefficient (ICC), and Bland and Altman analyses were used. For reproducibility, ICC, typical error, and coefficient of variation were used. No significant difference was found between AT test and retest determined using different methods. A positive correlation was observed between AT(Hoff) and AT(Hoff4.0). The MLSSHoff (10.6 +/- 1.3 km.h(-1)) was significantly different compared with AT(Hoff) (10.2 +/- 1.2 km.h(-1)) and AT(HoffBI) (9.5 +/- 0.4 km.h(-1)) but did not show any difference from LAn(Hoff4.0) (10.7 +/- 1.4 km.h(-1)). The MLSSHoff presented high ICCs with AT(Hoff) and AT(Hoff4.0) (ICC = 0.94; and ICC = 0.89; p <= 0.05, respectively), without significant correlation with AT(HoffBI). The results suggest that AT determined on the Hoff circuit is reproducible and capable of predicting MLSS. The AT(Hoff4.0) was the method that presented a better approximation to MLSS. Therefore, it is possible to assess submaximal physiological variables through a specific circuit performed with the ball in young soccer players.

Hamstrings-to-quadriceps strength and size ratios of male professional soccer players with muscle imbalance

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Brazilian soccer players and no-players adolescents: effect of the maturity status on the physical capacity components performance

The aim of this study was to compare the speed and the agility between Brazilian soccer players and non-players, regarding maturity status in adolescents 11-15 years old. Forty and two soccer players (age – 159.30±17.28 months old; weight – 48.45±9.96 kg; height – 1.53±0.10 m) and 45 non-players (age – 162.62±24.92 months old; weight – 48.30±8.35 kg; height – 1.54±0.12 m) participated of this study. Participants were classified by maturity status. On 2 different days with 1 week of differences between the assessments the participants were evaluated the agility, by Shuttle Run test, and the speed, by 30 m maximum speed test. The results showed that the maturity status was an influential factor in the performance with better results for individuals in a more advanced stage. The soccer practice does not seem to interfere in the performance of the physical capacity components analyzed, only effective when different maturity levels are involved in the analysis. It is also possible that late maturing boys selectively drop-out of soccer as age and sport specialization increase.

Correlation between Hoff test performance, body composition and aerobic and anaerobic fitness in professional soccer players

Purpose The purpose of the study was to investigate a possible association between the distance covered in the Hoff test with parameters of maximal oxygen uptake (V_O2MAX), anaerobic threshold, anaerobic fitness, and body composition of professional adult soccer players. Methods Twenty-five professional soccer players (20 ± 3 years) participated in the study. On different days the athletes performed: a graded incremental exercise test in a laboratory to measure V_O2MAX; a specific soccer field test called the Hoff test; a running anaerobic sprint test (RAST); an incremental test on an oval circuit to determine the velocity relative to anaerobic threshold (VAnT) and an estimation of body composition. Results The average V_O2MAX corresponded to 4.1 ± 0.1 L min-1 (54.1 ± 1.2 mL kg-1 min-1 ). The average distance covered during the Hoff test was 1,442.4 ± 30.0 m. The distance covered during the Hoff test showed significant correlations with absolute and expressed in an appropriated scale V_O2MAX (r = 0.44, p = 0.02; r = 0.42, p = 0.02, respectively) while no significant differences were found with body composition, VAnT and RAST variables. Conclusions The present study demonstrated that the distance covered during the Hoff test has weak correlation with V_O2MAX determined in treadmill running, and no correlation with VAnT, body composition and RAST outcomes, probably due to the non-specificity of the proposed tests when associated with the Hoff test.

A Preliminary Study: Body Dysmorphic Disorder in Division I Women’s Collegiate Soccer Players

The prevalence of Body Dysmorphic Disorder (BDD) among collegiate athletes has not been clearly determined. The purpose of this study was to determine if there are symptoms of body dysmorphic disorder found in Division I women’s soccer players. The researcher hypothesized that there would be some symptoms found within the participants of sport and that there was a need to research this area further. The study consisted of four participants who participated in semi-structured interviews. The subjects were asked a series of questions from the Yale-Brown Obsessive Compulsive Scale Modified for Body Dysmorphic Disorder (BDD-YBOCS) to determine if they indicated any symptoms of BDD. The prevalence of symptoms of BDD found among these four participants was very low. There was only one athlete who scored high on the questions that could be questionable of whether the indicators or symptoms of BDD were present. In conclusion there was not enough evidence to support the research hypothesis. The sample used was not a clear representation of all Division I women’s soccer players. Further research is needed to determine if BDD symptoms are found among Division I women’s soccer players.

Fit-climbing test: a field test for indoor rock climbing

Bertuzzi, R, Franchini, E, Tricoli, V, Lima-Silva, AE, Pires, FDO, Okuno, NM, and Kiss, MAPDM. Fit-climbing test: A field test for indoor rock climbing. J Strength Cond Res 26(6): 1558-1563, 2012-The aim of this study was to develop an indoor rock-climbing test on an artificial wall (Fit-climbing test). Thirteen climbers (elite group [EG] = 6; recreational group [RG] = 7) performed the following tests: (a) familiarization in the Fitclimbing test, (b) the Fit-climbing test, and (c) a retest to evaluate the Fit-climbing test's reliability. Gas exchange, blood lactate concentration, handgrip strength, and heart rate were measured during the test. Oxygen uptake during the Fit-climbing test was not different between groups (EG = 8.4 +/- 1.1 L; RG = 7.9 +/- 1.5 L, p > 0.05). The EG performance (120 +/- 7 movements) was statistically higher than the RG climbers' performance (78 +/- 13 movements) during the Fit-climbing test. Consequently, the oxygen cost per movement during the Fit-climbing test of the EG was significantly lower than that of the RG (p < 0.05). Handgrip strength was higher in the EG when compared with that in the RG in both pre-Fit- and post-Fit-climbing test (p < 0.05). There were no significant differences in any other variables analyzed during the Fit-climbing test (p > 0.05). Furthermore, the performance in the Fit-climbing test presented high reliability (intraclass correlation coefficient = 0.97). Therefore, the performance during the Fit-climbing test may be an alternative to evaluate rock climbers because of its specificity and relation to oxygen cost per movement during climbing.

EFFECT OF COMPETITION ON SALIVARY CORTISOL, IMMUNOGLOBULIN A, AND UPPER RESPIRATORY TRACT INFECTIONS IN ELITE YOUNG SOCCER PLAYERS

Mortatti, AL, Moreira, A, Aoki, MS, Crewther, BT, Castagna, C, de Arruda, AFS, and Filho, JM. Effect of competition on salivary cortisol, immunoglobulin A, and upper respiratory tract infections in elite young soccer players. J Strength Cond Res 26(5): 1396-1401, 2012-The present study examined the effect of a 20-day period of competition on salivary cortisol, mucosal immunity, and upper respiratory tract infections (URTI) in young male soccer players (n = 14). The players were monitored during the main under-19 Brazilian soccer championship, in which 7 matches were played in 20 days. Saliva samples were collected in the morning of each match and analyzed for cortisol and immunoglobulin A (IgA). Signs and symptoms of URTI were assessed across the study and a rating of perceived exertion (RPE) was obtained for each match. Compared with match 1, a significant increase in player RPE was observed in matches 4-7 (p < 0.05). Significant (p < 0.05) increases in the reporting of URTI occurred between matches 2 and 3, and 6 and 7, and this was accompanied by significant decreases in salivary IgA levels. Significant (p < 0.05) correlations were also seen between the individual reports of URTI and the decrease in IgA levels in match 2 (r = -0.60) and match 6 (r = -0.65). These results suggest that decrements in mucosal immunity, as measured by salivary IgA concentrations, may lead to a greater incidence of URTI in elite young soccer players. It may be speculated that the physiological and psychological stressors imposed by training and competition in a short timeframe are major contributing factors to these responses. Thus, the monitoring of salivary IgA could provide a useful and noninvasive approach for predicting URTI occurrences in young athletes during short-term competitions, especially if frequent sampling and rapid measurements are made.

Muscle lesion treatment in Brazilian soccer players: theory vs. practice

Background: In this study we evaluated the rehabilitation profile of Brazilian soccer players which underwent lower limb muscle lesions. Methods: This is a descriptive investigation. We evaluated 139 professional soccer players (1724 years old). We evaluated the following variables: muscle lesion diagnosis, symptoms, non steroidal anti-inflammatory used, physiotherapy treatment, which physiotherapy recourses was used if treated and train adaptation. Results: In great part of the athletes muscle lesion remained between 2 weeks and 1 month. Around 54% were diagnosed by a physician; the other part was diagnosed by a physical therapist. Non steroidal anti-inflammatory were prescribed by physicians in 42% of the cases; in 7% the physical therapist prescribed the medication while in 49% of the cases the masseur prescribed the drug. More than 1/4 of the athletes received physiotherapy treatement between 48 hours and 5 days. Isometric exercise therapy was applied in 15% of the cases. 63% were not accompanied by the physiotherapist on their return to the field. 48% received massages immediately after injury. Conclusion: We presented discrepancy between the recommended theory described by several researches and the practice. We indicate the necessity of recycling in a general context the rehabilitation of muscle injuries.

Preparation of percentile tables through anthropometric, performance, biochemical, hematological, hormonal and psychological parameters in professional soccer players

Introduction: The lack of reference values of anthropometric, performance, biochemical, hematological, hormonal and psychological parameters is an important limitation in the investigations with soccer players. Objective: To elaborate percentile tables to be used as comparison reference for further studies. Methods: 82 professional soccer players were evaluated approximately 30 days after the beginning of the main competition played by their teams. On the first day of evaluation, fast blood samples were collected for measurement of hematological parameters (i.e. erythrocytes, hemoglobin, hematocrit, mean corpuscular volume - MCV, mean corpuscular hemoglobin - MCH, mean corpuscular hemoglobin concentration - MCHC, leukocytes, eosinophils, lymphocytes, monocytes and platelets) and of concentrations of adrenaline, cortisol, creatine kinase, creatinine, norepinephrine, testosterone and urea. Subsequently, the soccer players had their anthropometric characteristics and psychological parameters assessed. In addition, the evaluation of the lactic anaerobic system efficiency was performed on a 400-m track. On the second day, both the alactic anaerobic and aerobic system efficiency was measured. Results: The percentile distribution (P-0, P-15, P-30, P-50, P-70, P-85 e P-100) was used to present the results. Conclusion: The elaboration of the percentile tables can be used as comparison reference for further studies.

Mechanical Alterations in airway smooth muscle after interaction with indoor pollutant – A mathematical model.

The viscoelasticity of mammalian lung is determined by the mechanical properties and structural regulation of the airway smooth muscle (ASM). The exposure to polluted air may deteriorate these properties with harmful consequences to individual health. Formaldehyde (FA) is an important indoor pollutant found among volatile organic compounds. This pollutant permeates through the smooth muscle tissue forming covalent bonds between proteins in the extracellular matrix and intracellular protein structure changing mechanical properties of ASM and inducing asthma symptoms, such as airway hyperresponsiveness, even at low concentrations. In the experimental scenario, the mechanical effect of FA is the stiffening of the tissue, but the mechanism behind this effect is not fully understood. Thus, the aim of this study is to reproduce the mechanical behavior of the ASM, such as contraction and stretching, under FA action or not. For this, it was created a two-dimensional viscoelastic network model based on Voronoi tessellation solved using Runge-Kutta method of fourth order. The equilibrium configuration was reached when the forces in different parts of the network were equal. This model simulates the mechanical behavior of ASM through of a network of dashpots and springs. This dashpot-spring mechanical coupling mimics the composition of the actomyosin machinery of ASM through the contraction of springs to a minimum length. We hypothesized that formation of covalent bonds, due to the FA action, can be represented in the model by a simple change in the elastic constant of the springs, while the action of methacholine (MCh) reduce the equilibrium length of the spring. A sigmoid curve of tension as a function of MCh doses was obtained, showing increased tension when the muscle strip was exposed to FA. Our simulations suggest that FA, at a concentration of 0.1 ppm, can affect the elastic properties of the smooth muscle ¯bers by a factor of 120%. We also analyze the dynamic mechanical properties, observing the viscous and elastic behavior of the network. Finally, the proposed model, although simple, incorporates the phenomenology of both MCh and FA and reproduces experimental results observed with in vitro exposure of smooth muscle to FA. Thus, this new mechanical approach incorporates several well know features of the contractile system of the cells in a tissue level model. The model can also be used in different biological scales.