Effects of physical training on the metabolic profile of rats exposed to chronic restraint stress.

INTRODUCTION: Despite strong evidences supporting the protective role of exercise against stress-induced repercussions, the literature remains inconclusive regarding metabolic aspects. Therefore, this study aimed to evaluate the effect of Physical Training (PT) by swimming on the metabolic parameters of rats subjected to restraint stress. METHODS: Wistar rats (n = 40) were divided into four groups: Control (C), Trained (T), Stressed (S), and Trained/Stressed (TS). The restraint stress protocol involved confining the animals in PVC pipes for 60 minutes/day for 12 weeks. Concurrently, the swimming PT protocol was performed without additional load in entailed sessions of 60 minutes conducted five days a week for the same duration. The following parameters were analyzed: fitness progression assessed by the physical capacity test, body mass, serum level of glucose, triglyceride, cholesterol and corticosterone, as well as glycemic tolerance test, evaluated after glucose administration (2 g/kg, i.p.). RESULTS: Trained groups (T and TS) exhibited enhanced physical capacity (169 ± 21 and 162 ± 22% increase, respectively) compared to untrained groups (C: 9 ± 5 and S: 11 ± 13% increase). Corticosterone levels were significantly higher in the S group (335 ± 9 nmoL/L) compared to C (141 ± 3 nmoL/L), T (174 ± 3 nmoL/L) and TS (231 ± 7 nmoL/L), which did not differ from each other. There were no significant changes in serum glucose, cholesterol, and triglyceride levels among the groups. However, the glycemic curve after glucose loading revealed increased glycemia in the S group (area under curve 913 ± 30 AU) but the TS group exhibited values (673 ± 12 AU) similar to the groups C (644 ± 10 AU) and T (649 ± 9 AU). CONCLUSION: Swimming-based training attenuated stress-induced corticosterone release and prevented glucose intolerance in rats, reinforcing the importance of exercise as a potential strategy to mitigate the pathophysiological effects of stress.

Strength training improves heart function, collagen and strength in rats with heart failure.

BACKGROUND/OBJECTIVES: Myocardial infarction (MI) frequently leads to cardiac remodeling and failure with impaired life quality, playing an important role in cardiovascular deaths. Although physical exercise is a well-recognized effective non-pharmacological therapy for cardiovascular diseases, the effects of strength training (ST) on the structural and functional aspects of cardiac remodeling need to be further documented. In this study, we aimed to investigate the role of a linear block ST protocol in the rat model of MI. METHODS AND RESULTS: After 6 weeks of MI induction or sham surgery, male adult rats performed ST for the following 12 weeks. The ladder-based ST program was organized in three mesocycles of 4 weeks, with one load increment for each block according to the maximal carrying load test. After 12 weeks, the infarcted-trained rats exhibited an increase in performance, associated with reduced cardiac hypertrophy and pulmonary congestion compared with the untrained group. Despite not changing MI size, the ST program partially prevented cardiac dilatation and ventricular dysfunction assessed by echocardiography and hemodynamics, and interstitial fibrosis evaluated by histology. In addition, isolated cardiac muscles from infarcted-trained rats had improved contractility parameters in a steady state, and in response to calcium or stimuli pauses. CONCLUSIONS: The ST in infarcted rats increased the capacity to carry mass, associated with attenuation of cardiac remodeling and pulmonary congestion with improving cardiac function that could be attributed, at least in part, to the improvement of myocardial contractility.

Effects of physical training on the metabolic profile of rats exposed to chronic restraint stress

Abstract Introduction: Despite strong evidences supporting the protective role of exercise against stress-induced repercussions, the literature remains inconclusive regarding metabolic aspects. Therefore, this study aimed to evaluate the effect of Physical Training (PT) by swimming on the metabolic parameters of rats subjected to restraint stress. Methods: Wistar rats (n = 40) were divided into four groups: Control (C), Trained (T), Stressed (S), and Trained/Stressed (TS). The restraint stress protocol involved confining the animals in PVC pipes for 60 minutes/day for 12 weeks. Concurrently, the swimming PT protocol was performed without additional load in entailed sessions of 60 minutes conducted five days a week for the same duration. The following parameters were analyzed: fitness progression assessed by the physical capacity test, body mass, serum level of glucose, triglyceride, cholesterol and corticosterone, as well as glycemic tolerance test, evaluated after glucose administration (2 g/kg, i.p.). Results: Trained groups (T and TS) exhibited enhanced physical capacity (169 ± 21 and 162 ± 22% increase, respectively) compared to untrained groups (C: 9 ± 5 and S: 11 ± 13% increase). Corticosterone levels were significantly higher in the S group (335 ± 9 nmoL/L) compared to C (141 ± 3 nmoL/L), T (174 ± 3 nmoL/L) and TS (231 ± 7 nmoL/L), which did not differ from each other. There were no significant changes in serum glucose, cholesterol, and triglyceride levels among the groups. However, the glycemic curve after glucose loading revealed increased glycemia in the S group (area under curve 913 ± 30 AU) but the TS group exhibited values (673 ± 12 AU) similar to the groups C (644 ± 10 AU) and T (649 ± 9 AU). Conclusion: Swimming-based training attenuated stress-induced corticosterone release and prevented glucose intolerance in rats, reinforcing the importance of exercise as a potential strategy to mitigate the pathophysiologi-cal effects of stress.

Effect of Supervised and Unsupervised Exercise Training in Outdoor Gym on the Lifestyle of Elderly People.

The aim of this study was to investigate the effectiveness of supervised and unsupervised physical training programs using outdoor gym equipment on the lifestyles of elderly people. METHODS: physically independent elderly people were randomly distributed into three groups: supervised training (n: 20; ST), unsupervised training (n: 20; UT) and control (n: 20; C). The ST and UT groups completed a 12-week program, with exercises performed three times a week. The ST group underwent weekly 30 min sessions consisting of a 5 min warm-up (walking at 60% of HRmax), followed by 20 sets of 30, "monitored by a metronome with 30" of passive recovery between sets and a five-minute cool-down. The following equipment was used: elliptical, rowing, surfing and leg press. The UT group was instructed to freely attend the gym and train spontaneously using the same equipment used by ST. Lifestyle changes were evaluated using a questionnaire containing specific domains. RESULTS: no significant differences were identified in the domains for family, physical activity, nutrition, smoking, sleep, behavior, introspection, work and overall score; however, the values corresponding to the alcohol domain for the ST and UT groups were lower (p < 0.05) than the C group, remaining even lower after the 12 weeks of intervention. Time effect (p < 0.05) was found only in the ST group for the physical domains, sleep, behavior and overall score. CONCLUSION: elderly people submitted to supervised and unsupervised physical exercise programs using outdoor gym equipment present positive changes in lifestyle parameters compared to physical inactive elderly people.

Skeletal Muscle Discomfort and Lifestyle of Brazilian Military Police Officers of Administrative and Tactical Force.

Our aim was to evaluate musculoskeletal discomfort and the lifestyle of military police officers of administrative and tactical force departments. Military police officers were distributed into two groups: administrative (Adm, n = 15) and tactical force (TF, n = 16) departments. Their lifestyle was assessed using the Fantastic Lifestyle questionnaire. Moreover, physical activity quantification was assessed using the International Physical Activity questionnaire, and musculoskeletal discomfort was quantified using the Corlett diagram. The mean total time of physical activity was 546 ± 276 min per week. No differences (p = 0.0832) were found between the Adm (454 ± 217 min) and TF (623 ± 301 min) groups. Concerning lifestyle, in general the sample presented very good (42%) and good (42%) style classification. For this parameter, no significant differences were found, but only a tendency was discovered (x2: 7.437; p = 0.0592); indeed, the TF presented a better classification (63%) of very good, compared to the Adm (53%) of good. No differences (p > 0.05) were found in musculoskeletal perception of discomfort between the right and left sides (p > 0.05) for all police officers and between the Adm and FT groups (p > 0.05). Military police officers showed high and moderate risk for waist circumference and waist-to-hip ratio, respectively; however, lifestyle and total time of physical activity were considered adequate without differences between military administrative and tactical force sectors.