Modelos matemáticos para estimativa do consumo máximo de oxigênio pela ventilometria de esforço em indivíduos saudáveis

The relation between metabolic demand and maximal oxygen consumption during exercise have been investigated in different areas of knowledge. In the health field, the determination of maximal oxygen consumption (VO2max) is considered a method to classify the level of physical fitness or the risk of cardiocirculatory diseases. The accuracy to obtain data provides a better evaluation of functional responses and allows a reduction in the error margin at the moment of risk classification, as well as, at the moment of determination of aerobic exercise work load. In Brasil, the use of respirometry associated to ergometric test became an opition in the cardiorespiratory evaluation. This equipment allows predictions concerning the oxyredutase process, making it possible to identify physiological responses to physical effort as the respiratory threshold. This thesis focused in the development of mathematical models developed by multiple regression validated by the stepwise method, aiming to predict the VO2max based on respiratory responses to physical effort. The sample was composed of a ramdom sample of 181 healthy individuals, men and women, that were randomized to two groups: regression group and cross validation group (GV). The voluntiars were submitted to a incremental treadmill test; objetiving to determinate of the second respiratory threshold (LVII) and the Peak VO2max. Using the método forward addition method 11 models of VO2max prediction in trendmill were developded. No significative differences were found between the VO2max meansured and the predicted by models when they were compared using ANOVA One-Way and the Post Hoc test of Turkey. We concluded that the developed mathematical models allow a prediction of the VO2max of healthy young individuals based on the LVII

Exercício aeróbico, resistência de artéria carótidae autonomia funcional em mulheres idosas

The aim of this study was to analyze the effects of an aerobic exercise program on the internal right carotid resistive index (IRCRI) and the functional autonomy levels of elderly women. The sample was composed of 25 elderly sedentary women, aged between 60 and 75 years, allocated into two groups: an experimental group consisting of 14 women submitted to aerobic treatment and a control group (n=11). Carotid artery resistance assessment was conducted using Doppler ultrasound and functional autonomy by the following tests: 10m walk (10mW), rising from a sitting position (RSP), rising from a chair and moving about the house (RCMH), rising from the ventral decubitus position (RVDP) and putting on and removing a t-shirt (PRTS). Aerobic training consisted of walking 30 minutes a day, 3 times a week, for 3 months. To control the intensity of the walk, the index of perceived exertion was used, with standardized Borg scale values corresponding to 13-15 points, characterized as slightly tiring exercise with training heart rate (TRH) between 50% and 80% of heart rate reserve (HRR). Repeated measures ANOVA was used for statistical analysis. Compared to the control, the experimental group obtained a statistically significant decrease in right internal carotid resistance (p = 0.021) and a significant increase in the following tests: 10mW (p=0.000), RSP (p=0.035) and RCMH (p=0.016). These results suggest that engaging in aerobic exercises was effective in decreasing IRCRI and improving functional autonomy inelderly women

Custos e benefícios de um programa de exercício aeróbios na doença pulmonar obstrutica crônica: ensaio cliníco aleatório controlado

Pulmonary Rehabilitation, especially due to aerobic exercise, positive impact in reducing morbidity/mortality of patients with COPD, however the economic impact with costs of implementing simple programs of aerobic exercise are scarce. This is a blind randomized clinical trials, which aimed to evaluate the costs and benefits of a simple program of aerobic exercise in individuals with COPD, considering the financial costs of the Public Health System and its secondary endpoints. We evaluated lung function, the distance walked during six minutes of walking, the respiratory and peripheral muscle strength, quality of life related to health (QLRH), body composition and level of activity of daily living (ADL) before and after eight weeks of an aerobic exercise program consisting of educational guidance for both groups, control and intervention and supervised walks to the intervention group. The health costs generated in both groups were calculated following table Brazilian Public Health System. The sample consisted of forty patients, two being excluded in the initial phase of desaturation during the walk test six minutes. Were randomized into control and intervention group thirty-eight patients, three were excluded from the control group and one was excluded from the intervention group. At the end, thirty-four COPD comprised the sample, 16 in the control group and 18 in the intervention group (FEV1: 50.9 ± 14% pred and FEV1: 56 ± 0.5% pred, respectively). After for intervention, the intervention group showed improvement in meters walked, the sensation of dyspnea and fatigue at work, BODE index (p <0.01) in QLRH, ADL level (p <0.001) as well as increased strength lower limbs (p <0.05). The final cost of the program for the intervention group was R $ 148.75, including: assessments, hiking supervised by a physiotherapist and reassessments. No patient had exacerbation of IG, while 2 patients in the CG exacerbated, generating an average individual cost of R $ 689.15. The aerobic exercises in the form of walking showed significant clinical benefits and economic feasibility of its implementation, due to low cost and easy accessibility for patients, allowing them to add their daily practice of aerobic exercises

Efeitos do treinamento aeróbio sobre sinais precoces do remodelamento do ventrículo esquerdo induzido pelo diabetes Mellitus experimental

Our aim was to investigate the effects of an aerobic training program on adverse and early left ventricle (LV) remodeling, using an experimental model of short-term type 1 diabetes (T1D). Wistar rats were divided in 4 groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). T1D was induced by streptozotocin (45 mg/kg). The training program consisted of 4 weeks running on a treadmill (13 m/min, 60 min/day, 5 days/week). At the end of the experiments, hearts were collected for analysis of morphology and transcriptional profile of LV, by focusing on its remodeling. Deaths were recorded during the 4-week period. We verified high mortality among animals of DS group, whereas it was significantly reduced in DT group. DS group also showed an increase in cross-sectional area of cardiomyocytes and fibrosis. TD group exhibited reduction in measures of cardiac trophism, but with respect to collagen content, it was similar to CS group. Analysis of gene expression related to cardiac remodeling revealed decreased expression of collagen I and III, as well as low expression of MMP-2 in DS group. TD group showed decreased levels of mRNA for MMP-9, and unchanged gene expression of MMP-2 when compared with the CS group. The expression of MMP-2 and TGF-1 were increased in CT group. The ratio between gene expression of collagen I and III was increased in the CT group and decreased in diabetic groups. These results establish early changes of the structure and transcriptional profile of LV myocardium. Moreover, they indicate that aerobic exercise training plays specific protection against mechanisms responsible for cardiac damage observed in T1D

Efeito agudo do exercício aeróbio vigoroso sobre as funções executivas em adolescentes

Executive functions are determinant cognitive processes for student success, since they execute and control complex cognitive activities such as reasoning, planning and solving problems. The development of the executive functions performances begin early at childhood going through the adolescence until adulthood, concomitant with the neuroanatomical, functional and blood perfusion changes over the brain. In this scenario, exercise has been considered an important environmental factor for neurodevelopment, as well as for the promotion of cognitive and brain health. However, there are no large scientific studies investigating the effects of a single vigorous aerobic exercise session on executive functions in adolescents. Objective: To verify the acute effect of vigorous aerobic exercise on executive functions in adolescents. Methods: A randomized controlled trial (RCT) with crossover design was used. 20 pubescent from both sexes/gender with age between 10 and 16 years were submitted to two sessions of 30min each: 1) The aerobic exercise session intensity was between 65 and 75% of heart rate reserve, in which 5min for warm-up, 20min at the target intensity and 5min of cool down; and 2) control session watching cartoons. The computerized Stroop test – Testinpacs and trail making test were used to evaluate the inhibitory control and cognitive flexibility assessment respectively, before and after both experimental and control sessions. The reaction time (RT) and number of errors (n) of Stroop test were recorded. The total time (TT) and the number of errors (n) of the trail making test were also recorded. Results: The control session’s RT did not present significant differences in the Stroop test. On the other hand, the exercise session’s RT decreased significantly (p<0.01) after the session. The number of errors made at the Stroop test had no significant differences in control and exercise sessions. The ΔTT of trail making test of exercise session was significantly (p<0.001) lower than the control session’s. Errors made in trail making test did not show significant differences between control and exercise sessions. Additionally, there was significant and positive association among the Stroop test ΔRT of exercise session with xiii chronological age (r= 0.635, p=0.001; r 2 = 0.404, p=0.003) and sexual maturation (rs= 0.580, p=0.007; r 2 = 0.408, p=0.002). Differently, there was no association among the control session ΔRT and chronological age (r= – 0.144, p=0.273; r 2 = 0.021, p=0.545) or sexual maturation (rs= –0.155, p=0.513; r 2 = 0.015, p=0.610). Conclusion: Vigorous aerobic exercise seems to improve acutely executive functions in adolescents. The effect of exercise on inhibitory control performance was associated to pubertal stage and chronological age. In other words, the benefits of exercise were more evident in early adolescence (↑ ΔRT) and its magnitude decreases along the growing up process.

Efeitos dos exercícios aeróbio contínuo e intervalado na variabilidade da frequência cardíaca em adultos jovens saudáveis. Ensaio clínico aleatório

The high-intensity interval exercise has been described as an option for increasing physical activity and its use also being suggested in the therapeutic management of many conditions such as diabetes mellitus and heart failure. However, the knowledge of its physiological effects and parameters that can assure greater safety for interval exercise prescription; especially its effect on short- and medium-term (24 hours after exercise) exercise recovery, need to be clarified. This study objective was to evaluate the effect of continuous and interval aerobic exercise on the cardiac autonomic control immediate and medium term (24 hours), by assessing heart rate variability (HRV). The present study is a randomized crossover clinical trial in which healthy young individuals with low level of physical activity had the VFC 24 hours measured by a heart rate sensor and portable accelerometer (3D eMotion HRV, Kuopio, Finland) before and after continuous aerobic exercise (60-70% HR max, 21 min.) and interval exercise (cycle 1 min. 80-90% HR max, 2 min. at 50-60% HR max, duration 21 min.). HRV was measured in the time and frequency domain and the sympathovagal balance determined by the ratio LF / HF. Nonlinear evaluation was calculated by Shannon entropy. The data demonstrated delayed heart rate recovery immediate after exercise and lower HR after 24 hours compared to pre intervention values, especially in the interval exercise group. There was a tendency to higher predominance and representatives index values of sympathetic stimulation during the day in interval exercise group; however, without statistical significance. The study results help to clarify the effects of interval exercise on the 24 hours following interval exercise, setting parameters for prescription and for further evaluation of groups with metabolic and cardiovascular diseases.

Efeitos da terapia laser de baixa intensidade associada ao exercício aeróbio no reparo de tenotomia do tendão de aquiles de ratos diabéticos

Diabetes Mellitus (DM ) is a complex disease that requires continuous medical care for the reduction of risk factors in addition to glycemic control. The typical hyperglycemia of this disease produces glycosylation of proteins and so the consequence is the accumulation of glycosylation final products in various human tissues, among them, the tendon. The aerobic exercise (AE) and the low level laser therapy (LLLT) have been used to treat tendinopathies in individuals with or without DM. Objective: The aim of this study was to watch the effect of the LLLT and the AE, in association, in partial tenotomy of the tissue repair of the Achilles tendon (AT) of diabetic rats. Methods: 91 animals were utilized and divided in to the following groups: control group (GC), injured control group (GCL), diabetic group (GD), diabetic group LLLT (GD – TLBI), diabetic group trained (GD - EX) and diabetic group trained laser (GD-EX+TLBI). The animals were submitted to intervention with AE, using a protocol with a progressive increase of time (12 to 60 min) and speed of (4 to 9 m/min), and the LLLT (660 nm laser, 10mW, 4 J/cm², single point for 16 seconds, three times for week). It was analyzed morphological, biomechanical and molecular characteristics. For data showing normal distribution was used one-way ANOVA test and post hoc Tukey and data without normal distribution was used Mann Whitney test and post hoc Dunn's. It was accepted p <0.05 for statistical significance Results: The biomechanical tests indicated major improvement in the GC and GD-EX+TLBI groups when compared with the diabetic groups in the following variables: maximum load, strain, absorbed energy, stress, cross section area, elastic modulus and energy density (p<0.05). The analysis through molecular biology indicated that the association of aerobic exercise and LLLT generated an increase of the collagen I gene expression and modulated the expression of the MMP2 and MMP9 (p<0.05). No observed any major improvement in the morphological variable studied. Conclusion: the LLLT associated with aerobic exercise promotes and increase of the mechanical properties, in the control of collagen I gene expression and of the MMP2 and MMP9 of the diabetic rats.