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Development and Validation of an Automated Step Ergometer

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C. de Sousa M. d. S., Aniceto R. R., Neto G. R., T. de Araújo R. C., C. de Sousa J. B., Costa J. A. D., Pellegrinotti I. L.
Journal of Human Kinetics
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2014
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vol. 43
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issue 1
113-124
EN
Laboratory ergometers have high costs, becoming inaccessible for most of the population, hence, it is imperative to develop affordable devices making evaluations like cardiorespiratory fitness feasible and easier. The objective of this study was to develop and validate an Automated Step Ergometer (ASE), adjusted according to the height of the subject, for predicting VO2max through a progressive test. The development process was comprised by three steps, the theoretical part, the prototype assembly and further validation. The ASE consists in an elevating platform that makes the step at a higher or lower level as required for testing. The ASE validation was obtained by comparing the values of predicted VO2max (equation) and direct gas analysis on the prototype and on a, treadmill. For the validation process 167 subjects with average age of 31.24 ± 14.38 years, of both genders and different degrees of cardiorespiratory fitness, were randomized and divided by gender and training condition, into untrained (n=106), active (n=24) and trained (n=37) subjects. Each participant performed a progressive test on which the ASE started at the same height (20 cm) for all. Then, according to the subject’s height, it varied to a maximum of 45 cm. Time in each stage and rhythm was chosen in accordance with training condition from lowest to highest (60-180 s; 116-160 bpm, respectively). Data was compared with the student’s t test and ANOVA; correlations were tested with Pearson’s r. The value of α was set at 0.05. No differences were found between the predicted VO2max and the direct gas analysis VO2max, nor between the ASE and treadmill VO2max (p= 0.365) with high correlation between ergometers (r= 0.974). The values for repeatability, reproducibility, and reliability of male and female groups measures were, respectively, 4.08 and 5.02; 0.50 and 1.11; 4.11 and 5.15. The values of internal consistency (Cronbach’s alpha) among measures were all >0.90. It was verified that the ASE prototype was appropriate for a step test, provided valid measures of VO2max and could therefore, be used as an ergometer to measure cardiorespiratory fitness.
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Resistance Training in Type 2 Diabetic Patients Improves Uric Acid Levels

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R. Sousa M. S. S., Saavedra F. J. F., Neto G. R., Novaes G. S., Souza A. C. R., Salerno V. P., Novaes J. S.
Journal of Human Kinetics
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2014
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vol. 43
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issue 1
17-24
EN
Resistance training (RT) can provide several benefits for individuals with Type 2 diabetes. The aim of this study was to investigate the effects of resistance training on the strength levels and uric acid (UA) concentration in individuals with Type 2 diabetes. The study included 68 patients (57.7±9.0 years) that participated in an organized program of RT for 12 weeks. The volunteers were divided into two groups: an experimental group (EG; n=34) that performed the resistance training program consisting of seven exercises executed in an alternating order based on segments; and a control group (CG; n=34) that maintained their normal daily life activities. Muscle strength and uric acid were measured both pre- and post-experiment. The results showed a significant increase in strength of the subjects in the EG for all exercises included in the study (p<0.001). Comparing the strength levels of the post-test, intergroup differences were found in supine sitting (p<0.001), leg extension (p<0.001), shoulder press (p<0.001), leg curl (p=0.001), seated row (p<0.001), leg press (p=0.001) and high pulley (p<0.001). The measured uric acid was significantly increased in both experimental and control groups (p<0.001 and p=0.001, respectively). The intergroup comparison showed a significant increase for the EG (p=0.024). We conclude that the training program was effective for strength gains despite an increase in uric acid in Type 2 diabetics.
3
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Acute Effects of Different Stretching Techniques on the Number of Repetitions in A Single Lower Body Resistance Training Session

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Sá M. A., Neto G. R., Costa P. B., Gomes T. M., Bentes C. M., Brown A. F., Novaes J. S.
Journal of Human Kinetics
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2015
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vol. 45
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issue 1
177-185
EN
This study aimed to investigate the acute effects of passive static and ballistic stretching on maximal repetition performance during a resistance training session (RTS). Nine male subjects underwent three experimental conditions: ballistic stretching (BS); passive static stretching (PSS); and a specific warm-up (SW). The RTS was composed of three sets of 12RM for the following exercises: leg press 45 (LP), leg extension (LE), leg curl (LC), and plantar flexors (PF). Performance of six sessions was assessed 48 hours apart. The first visit consisted of a familiarization session including stretching methods and exercises used in the RTS. On the second and third visit, a strength test and retest were performed. During the fourth to the sixth visit, the volunteers randomly performed the following protocols: BS+RTS; PSS+RTS; or SW+RTS. For the sum of the RM number of each three-set exercise, significant differences were found between PSS vs. SW for the LP (p = 0.001); LE (p = 0.005); MF (p = 0.001); and PF (p = 0.038). For the comparison between the methods of stretching PSS vs. BS, significant differences were found only for the FP (p = 0.019). When analyzing the method of stretching BS vs. SW, significant differences were found for the LP (p = 0.014) and MF (p = 0.002). For the total sum of the RM number of three sets of the four exercises that composed the RTS, significant differences were observed (p < 0.05) in the following comparisons: PPS vs. SW (p = 0.001), PPS vs. BS (p = 0.008), and BS vs. SW (p = 0.002). Accordingly, the methods of passive static and ballistic stretching should not be recommended before a RTS.
4
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Effects of High-Intensity Blood Flow Restriction Exercise on Muscle Fatigue

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Neto G. R., Santos H. H., Sousa J. B. C., Júnior A. T. A., Araújo J. P., Aniceto R. R., Sousa M. S. C.
Journal of Human Kinetics
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2014
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vol. 41
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issue 1
163-172
EN
Strength training combined with blood flow restriction (BFR) have been used to improve the levels of muscle adaptation. The aim of this paper was to investigate the acute effect of high intensity squats with and without blood flow restriction on muscular fatigue levels. Twelve athletes (aged 25.95 ± 0.84 years) were randomized into two groups: without Blood Flow Restriction (NFR, n = 6) and With Blood Flow Restriction (WFR, n = 6) that performed a series of free weight squats with 80% 1-RM until concentric failure. The strength of the quadriceps extensors was assessed in a maximum voluntary isometric contraction integrated to signals from the surface electromyogram. The average frequency showed significant reductions in the WFR group for the vastus lateralis and vastus medialis muscles, and intergroup only for the vastus medialis. In conclusion, a set of squats at high intensity with BFR could compromise muscle strength immediately after exercise, however, differences were not significant between groups.
5
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Can Programmed or Self-Selected Physical Activity Affect Physical Fitness of Adolescents?

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Neto C. F., Neto G. R., Araújo A. T., Sousa M. S. C., Sousa J. B. C., Batista G. R., Reis V. M. M. R.
Journal of Human Kinetics
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2014
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vol. 43
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issue 1
125-130
EN
The aim of this study was to verify the effects of programmed and self-selected physical activities on the physical fitness of adolescents. High school adolescents, aged between 15 and 17 years, were divided into two experimental groups: a) a self-selected physical activity group (PAS) with 55 students (aged 15.7 ± 0.7 years), who performed physical activities with self-selected rhythm at the following sports: basketball, volleyball, handball, futsal and swimming; and b) a physical fitness training group (PFT) with 53 students (aged 16.0 ± 0.7 years), who performed programmed physical fitness exercises. Both types of activity were developed during 60 min classes. To assess physical fitness the PROESP-BR protocol was used. The statistical analysis was performed by repeated measures ANOVA. The measurements of pre and post-tests showed significantly different values after PFT in: 9 minute running test, medicine ball throw, horizontal jump, abdominal endurance, running speed and flexibility. After PAS differences were detected in abdominal endurance, agility, running speed and flexibility. The intervention with programmed physical activity promoted more changes in the physical abilities; however, in the self-selected program, agility was improved probably because of the practice of sports. Therefore, physical education teachers can use PFT to improve cardiorespiratory fitness and power of lower and upper limbs and PAS to improve agility of high school adolescents.
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