Treadmill Exercise Training Prevents Myocardial Mechanical Dysfunction Induced by Androgenic-Anabolic Steroid Treatment in Rats

Elevated concentrations of testosterone and its synthetic analogs may induce changes in cardiovascular function. However, the effects of the combination of anabolic/androgenic steroid (AAS) treatment and exercise training on systolic and diastolic cardiac function are poorly understood. in the present study, we aimed to investigate the effects of low-dose steroid treatment (stanozolol) on cardiac contractile parameters when this steroid treatment was combined with exercise training in rats and the effects of chronic steroid treatment on the Frank-Starling (length-tension curves) relationship. Male Wistar rats were randomly assigned to one of four groups: U (untrained), US (untrained and treated with stanozolol 5 mg/kg/week), T (trained, 16 m/min/1 h) and TS (trained and treated with stanozolol 5 mg/kg/week). Continuous exercise training was conducted 5 days/week for 8 consecutive weeks. the speed of the treadmill was gradually increased to a final setting of 16 m/min/1 h. Experiments were divided into two independent series: 1) central hemodynamic analysis for mean arterial blood pressure (MAP) and cardiac output (CO) measurements and 2) isolated papillary muscle preparation in Krebs solution. Stanozolol treatment significantly increased the MAP and the heart size in untrained and trained rats (U 113 +/- 2; T 106 +/- 2; US 138 +/- 8 and TS 130 +/- 7 mmHg). Furthermore, stanozolol significantly decreased developed tension and dT/dt (maximal and minimal) in U rats. However, the developed tension was completely restored by training. the Frank/Starling relationship was impaired in rats treated with stanozolol; however, again, training completely restored diastolic function. Taken together, the present data suggest that AAS treatment is able to decrease cardiac performance (systolic and diastolic functions). the combination of stanozolol and physical training improved cardiac performance, including diastolic and systolic functions, independent of changes in central hemodynamic parameters. Therefore, changes in ventricular myocyte calcium transients may play a cardioprotective role.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Sao Judas Tadeu, Dept Post Grad Phys Educ, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, Div Cardiovasc, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, Div Cardiovasc, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, São Paulo, BrazilWeb of Scienc

Effects of vitamin D supplementation on pulmonary function in postmenopausal women following an aquatic exercise program

Objective: This study sought to investigate the effects of vitamin D supplementation and aquatic exercise on pulmonary function in postmenopausal women. Materials and methods: This prospective and controlled study included 104 women (62 +/- 6.5 years) divided into three groups: a control group lacking vitamin D and calcium supplementation which remained sedentary (CGn = 17)a control group receiving vitamin D and calcium supplementation which remained sedentary (CDG, n = 33)and a group that completed aquatic exercises three times a week and received vitamin D and calcium supplementation (DTG, n = 54). Data before and after 6 months of the study were analyzed, including serum 25-hydroxyvitamin D (25(OH) D) and calcium concentrations, peak expiratory flow (PEF), forced vital capacity (FVC), and cirtometry. Results: We observed significant increases in 25(OH) D concentrations in CDG (52.9 +/- 2.4 to 69.1 +/- 2.2nmol/Lp < 0.0001) and DTG groups (55.5 +/- 3 to 71.5 +/- 3 nmol/Lp < 0.0001). PEF increased by 7 +/- 2% (p = 0.0080) in CDG group and 11 +/- 2% (p < 0.0001) in DTG group, whereas FVC increased by 7 +/- 2% (p = 0.0016) in the CDG group and 10 +/- 2% (p < 0.0001) in the DTG group, whereas CG had no changes in any of these parameters. The increment value of cirtometry in DTG group (+ 43 +/- 3%) were significantly (p < 0.0001) higher than those in CG (-4 +/- 8%) and CDG (+ 4 +/- 9%) groups. Conclusion: Our data suggest that vitamin D supplementation improves pulmonary function parameters in postmenopausal women.Fapesp (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)Federal AgencFederal Agency for Support and Evaluation of Graduate Education (Higher Education Personnel Improvement Coordination - Capes)Univ Fed Sao Paulo, Dept Med, Disciplina Endocrinol, Fac Med,Unifesp,EPM, Sao Paulo, SP, BrazilUniv Sao Judas Tadeu, Fisiol Translac, Programa Posgrad Educ Fis & Ciencias Envelhecimen, Sao Paulo, SP, BrazilUniv Sao Paulo, Escola Educ Fis & Esporte, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Med, Disciplina Endocrinol, Fac Med,Unifesp,EPM, Sao Paulo, SP, BrazilFAPESP: 08/50179-9Web of Scienc

Prior exercise training does not prevent acute cardiac alterations after myocardial infarction in female rats

OBJECTIVE: This study aimed to investigate whether previous exercise training could prevent or attenuate acute cardiac alterations after myocardial infarction. METHODS: Female rats were submitted to swim training (1 h/day; 5 days/week) or allowed to remain sedentary for 8 weeks. Afterwards, they were randomly assigned to left coronary artery occlusion or sham surgery. After this procedure, the rats remained sedentary for one week until euthanasia. Cardiac structural and functional analyses were performed using Doppler echocardiography. The rats that had a moderate or large infarct size were included in the evaluations. The data (mean + SEM) were analyzed using a two-way ANOVA model followed byTukey's post-hoc test. RESULTS: After the surgery, no significant difference between the exercise and sedentary groups was observed in the left ventricular infarct sizes (34.58 + 3.04 vs. 37.59 + 3.07). In another group of rats evaluated with Evans blue 1 h after myocardial infarction, no siginificant difference in the area at risk was observed between the exercised and sedentary rats (49.73 + 1.52 vs. 45.48 + 3.49). The changes in the left ventricular fractional areas for the exercised and sedentary myocardial infarction groups (36 + 2% and 39 + 3%, respectively) were smaller than those for the exercise sham surgery (ES, 67+1%) and sedentary sham surgery (SS, 69 + 2%) groups. The E/A was higher in the sedentary myocardial infarction (4.4 + 0.3) and exercised myocardial infarction (5.5 + 0.3) rats than in the SS (2.4 + 0.1) and ES (2.2 + 0.1) rats. CONCLUSION: Previous swim training of female rats does not attenuate systolic and diastolic function alterations after myocardial infarction induced by left coronary artery occlusion, suggesting that cardioprotection cannot be provided by exercise training in this experimental model

Comparison of the Effects of Linear and Non-Linear Resistance Training Periodization on Morphofunctional Capacity of Subjects with Different Fitness Levels: A Systematic Review

International Journal of Exercise Science 12(4): 666-690, 2019. Resistance training (RT) is recognized as an efficient method to improve muscle strength, power, hypertrophy; all are fundamental components of functional health and quality of life. Variables of RT such as volume, intensity, density, rest interval, duration, exercise order and selection, training frequency, and periodization models (i.e. linear periodization (LP), reverse linear periodization (RLP), block periodization (BP), and nonlinear periodization (NLP): undulating periodization (UP) and weekly undulating periodization (WUP)) are manipulated to potentiate musculoskeletal adaptations. The aim of the present study was to conduct a systematic review of studies comparing different periodization models on morphofunctional capacity in adults with different levels of physical activity. Databases from Ebsco, PubMed and Web of Science were searched between January 2007 and June 2017 using the following descriptors: RT; strength training; LP; UP; daily UP; NLP. From the 4337 articles found, 11 met the inclusion criteria. The mean number of sets in each RT model was 3 ± 1 for both (LP and UP), mean repetitions used was 10 ± 5, and the mean inter-set rest interval was 2 ± 1 minutes . The mean number of exercises was 7 ± 3 with training duration ranging from 45 to 90 minutes. The number of sets, repetitions, rest interval, and load intensity were minimally detailed in 12% of articles evaluated. In conclusion, RT programs that used LP and UP presented discrepant results, which precludes a consensus at this time. Most characteristics and differences between studies reported here should be used in future experimental designs to improve our understanding about periodization models

Effects of previous carbohydrate supplementation on muscular fatigue: double-blind, randomized, placebo-controlled crossover study

Abstract AIMS The aim of this study was to examine the effects of previous carbohydrate supplementation on high-volume resistance exercise performance METHODS Twenty males physically independent adults aged ≥18 years participated in a double-blind randomized placebo-controlled crossover study. Sixty minutes before the experimental protocol, each participant ingested 0,6 g.kg of body mass-1 of carbohydrate supplementation or placebo. Maximum voluntary isometric contraction tests were performed before and after the dynamic fatigue induction protocol consisting of 10 sets of 8 repetitions of right leg knee extensors at 120º s-1. RESULTS Lower decrement of the isometric peak torque (p<0,001) and of the rate of torque development (p<0,001) was observed in carbohydrate supplementation after the dynamic protocol. Both concentric and eccentric peak torque differed significantly (p<0,001) between carbohydrate supplementation and placebo treatments from the second set, although the slope of the force-repetitions curve was not different between them. Additionally, the carbohydrate supplementation resulted in a lower session rating of perceived exertion (p<0,05). CONCLUSIONS Previous carbohydrate supplementation attenuates muscle fatigue and internal load exercise in a high-volume isokinetic leg protocol

Futsal as a strategy for the improvement of elementary abilities and for the development of the body image in children

This current study aims to analyze the contribution of futsal practice in global praxis and body image in children in a specialized motor stage, evaluating the motor performance before and after an intervention in the following factors: hands and feet global praxis and body image. It was adopted the application method of 18 one-hour twice a week session, divided into three modules, I) displacement activities in different directions; II) coordination activities and reaction time and III) throwing and kicking activities. Twenty male participants, aged 8 to 12 years, with normal motor development were used. The survey was conducted at a private school. The results found were a significant improvement in the hits of the tennis balls with hands and make the number of hits in kicking the ball with his feet. Regarding the analysis of body image after the proposed intervention, the children has shown the body parts performance incorporated in drawings that were not previously present. It is concluded that there are positive contributions of the futsal practice in respect to the global praxis practice and body image in children in a specialized motor stage

Effects of a Competitive Season on Autonomic Heart Rate Modulation in Field Soccer Athletes

International Journal of Exercise Science 12(2): 1198-1205, 2019. The physical demands of soccer combined with the rigor of the competitive season may have a substantial impact on autonomic modulation in field soccer athletes. The number of sudden death cases associated with soccer may be related to the physical training required to maintain performance and fitness, minimal time for recovery, and recurrent game participation. It is possible to identify individuals at risk of cardiovascular events by measuring heart rate variability (HRV), which is an indirect method for assessing autonomic activity. Therefore, the objective of this study was to analyze HRV before and after a period of field soccer competition. We evaluated 17 healthy male professional field soccer athletes and 12 untrained controls. The HRV was analyzed during supine rest before and after a period of field soccer competition. The following parameters were evaluated: interval R wave variation (RR), standard deviation of normal–normal intervals (SDNN), Root-mean-square successive difference (RMSSD), low frequency component (LF), high-frequency component (HF) and sympathovagal balance (LF/HF). Results indicated that the RR (p\u3c .05, ES: 2.77), SDNN (p \u3c .05, ES: 1.70), LF (p\u3c .05, ES: 1.86), HF (pp\u3c .05, ES: 0.89) all decreased after the competition in the professional athletes with no change observed in the control group. In conclusion, the data suggest that a soccer competition negatively influences the autonomic regulation of heart rate

Prior exercise training and experimental myocardial infarction: A systematic review and meta-analysis

Exercising prior to experimental infarction may have beneficial effects on the heart. The objective of this study was to analyze studies on animals that had exercised prior to myocardial infarction and to examine any benefits through a systematic review and meta-analysis. The databases MEDLINE, Google Scholar, and Cochrane were consulted. We analyzed articles published between January 1978 and November 2018. From a total of 858 articles, 13 manuscripts were selected in this review. When animals exercised before experimental infarction, there was a reduction in mortality, a reduction in infarct size, improvements in cardiac function, and a better molecular balance between genes and proteins that exhibit cardiac protective effects. Analyzing heart weight/body weight, we observed the following results - Mean difference 95% CI - -0.02 [-0.61,0.57]. Metaanalysis of the infarct size (% of the left ventricle) revealed a statistically significant decrease in the size of the infarction in animals that exercised before myocardial infarction, in comparison with the sedentary animals -5.05 [-7.68, -2.40]. Analysis of the ejection fraction, measured by echo (%), revealed that animals that exercised before myocardial infarction exhibited higher and statistically significant measures, compared with sedentary animals 8.77 [3.87,13.66]. We conclude that exercise performed prior to experimental myocardial infarction confers cardiac benefits to animals

Description of training loads using whole body exercise during high-intensity-interval-training

OBJECTIVES: To describe external training load and internal training load through sets of a single session of high-intensity interval training (HIIT) body work. METHODS: Twenty male individuals (24±3 years) performed a HIIT body work protocol consisting of a single bout of exercise with 1:1 stimuli. The exercises used were 30 min in duration with “all-out” intensity. The exercises included jumping jacks, mountain climbers, burpees and squat jumps, totaling 20 min of exercise. During exercise, total movement capacity, blood lactate measurement, ratings of perceived exertion and recovery, training load and intensity were monitored. RESULTS: The single bout examined showed a total of 382±89 movements. Differences (p<0.01) in the total amount of movement for each exercise were noted, reflecting the difficulty of maintaining exercise over time. Increases in lactate concentrations (before: 0.98±0.16, after: 14.10±1.66; mmol/L) were found postexercise. Significant differences (p<0.01) were found after the fifth set, and the values for movement capacity remained higher than the values of the first set, demonstrating high load in a single session. No differences in ratings of perceived exertion (RPE) during the sets were found. However, the ratings of perceived recuperation from the second set were significantly (p<0.01) lower than those from the first set. CONCLUSIONS: The exercise protocol used in this study was of high intensity and produced large values for stress during performance, with increases recorded for the internal load indicators