RESUMO
The aim was to investigate the long-term effects of metformin ingestion on high-intensity interval training on performance, glycogen concentration (GC), GLUT-4 content, and metabolomics outcomes in rats. Fifty male Wistar rats were randomly divided into baseline, metformin (500 mg daily), and control groups. Training consisted of 4 sets of 10 jumps with 30 s of passive recovery per day, 5 days/week for 8 weeks. The intensity equivalent was 50% of body mass (BM) in the first four weeks and 70% of BM in the last four weeks. The animals were submitted to a weekly jump test until exhaustion at 50% of BM. Serum and tissues were collected at baseline and after 4 and 8 weeks for biochemical and metabolomics analysis. The number of jumps increased in the Control group without a significant difference between groups at 4 and 8 weeks. GLUT4 was lower in the gastrocnemius muscle in the Metformin at the fourth week compared to Control (P=0.03) and compared to Metformin (P=0.02) and Control (P=0.01) at eight weeks. Hepatic and soleus GC were not altered by metformin. Gastrocnemius GC was lower after 8 weeks in the Metformin group compared to Control (P=0.01). Significantly lower levels of pyruvate and phenylalanine and higher levels of ethanol, formate, betaine, very low-density lipoprotein, low-density lipoprotein, and creatine were found in the Metformin compared to the Control. Although chronic administration of metformin decreased food intake and negatively influenced the synthesis of muscle glycogen, it did not significantly change physical performance compared to the Control.
RESUMO
According to the developmental origins of health and disease (DOHaD) hypothesis, changes in the maternal environment are known to reprogram the metabolic response of offspring. Known for its redox modulation, caloric restriction extends the lifespan of some species, which contributes to diminished cellular damage. Little is known about the effects of gestational caloric restriction, in terms of antioxidant parameters and molecular mechanisms of action, on the reproductive organs of offspring. This study assessed the effects of moderate (20%) caloric restriction on redox status parameters, molecular expression of sirtuin (SIRT) 1 and SIRT3 and histopathological markers in the ovaries and testes of adult rats that were subjected to gestational caloric restriction. Although enzyme activity was increased, ovaries from female pups contained high levels of oxidants, whereas testes from male pups had decreased antioxidant enzyme defences, as evidenced by diminished glyoxalase I activity and reduced glutathione content. Expression of SIRT3, a deacetylase enzyme related to cellular bioenergetics, was increased in both ovaries and testes. Previous studies have suggested that, in ovaries, diminished antioxidant metabolism can lead to premature ovarian failure. Unfortunately, there is little information regarding the redox profile in the testis. This study is the first to assess the redox network in both ovaries and testes, suggesting that, although intrauterine caloric restriction improves molecular mechanisms, it has a negative effect on the antioxidant network and redox status of reproductive organs of young adult rats.
Assuntos
Restrição Calórica/efeitos adversos , Mitocôndrias/metabolismo , Ovário/metabolismo , Efeitos Tardios da Exposição Pré-Natal , Sirtuínas/análise , Testículo/metabolismo , Animais , Antioxidantes/análise , Antioxidantes/metabolismo , Feminino , Masculino , Ovário/química , Oxirredução , Gravidez , Ratos , Ratos Wistar , Sirtuína 1/análise , Sirtuína 3/análise , Testículo/químicaRESUMO
Besides technical and tactical aspects, basketball matches involve high aerobic and anaerobic capacities, conferring the final performance of a team. Thus, the evaluation of physical and technical responses is an effective way to predict the performance of athletes. Field and laboratory tests have been used in sports. The first involving high ecological validity and low cost, and the second, greater control and accuracy but not easy application, considering the different preparation phases in a season. This study aimed, through complex networks analysis, to verify whether centrality parameters analysed from significant correlations behave similarly in distinct scenarios (laboratory and on-court), emphasizing aerobic and anaerobic physical parameters and technical performances. The results showed that, in a compelling analysis involving basketball athletes, the studied centralities (degree, betweenness, eigenvector and pagerank) revealed similar responses in both scenarios, which is widely attractive considering the greater financial economy and lower time when applying tests in the field.
RESUMO
The 3-min all-out test was developed and validated on a cycle ergometer using a modification of a linear mathematical equation (1/time vs. power) obtained from the original critical power model. The purpose of this development was to obtain, in a single test, the aerobic and anaerobic capacity parameters and identify the exercise transition moment from heavy to severe intensity. The aim of this study was to propose an adaptation of the all-out 3-min cycle ergometer to a non-motorized treadmill with tethered running. In addition, we tested the reproducibility of this adapted protocol, highlighting the need for mechanical power evaluation using a specific ergometer. Consequently, 10 physically active individuals visited the laboratory 4 times for testing and data collection. The results suggested that the protocol adaptation for the 3-min all-out test for non-motorized treadmill with tethered running was reproducible and feasible. It was also possible to show that the AO3 application in this ergometer ensures the specificity of the sports that involve the running exercise, from assessment of both aerobic and anaerobic parameters, accomplished in a single day of application.